MBB1 Flashcards

Question

What is a partial reinforcement schedule?

Answer 1

- Schedules when the learner only receives the reinforcement some of the time - Creates more persistent learning than continuous □ Gambling - pays off sometimes - just enough to think that maybe next time they will get the reward □ Keeps learner looking for the next reward ○ Start with continuous reinforcement then drop to partial reinforcement

Answer 2

○ Extinction occurs when reinforcement is withheld ○ Not immediate - may be brief increase in responding (extinction burst) followed by decrease in trained behaviour (eg tantrum) ○ Increase in more variable behaviour (ideal for shaping) ○ Responses that were reinforced partially are more difficult to extinguish than those reinforced continuously

Answer 3

The reinforcement of successive approximations to desired behaviour (reinforcing small steps)

Answer 4

○ Start by reinforcing a high frequency component of desired response - Since it won't naturally occur at the start, start rewarding the behaviour that is closer and closer to the desired behaviour - Build up to more sophisticated behaviour ○ Then drop reinforcement - behaviour becomes more variable again ○ Await response that is still closer to the desired response - reintroduce the reinforcer ○ Continue cycling through as closer and closer approximations to the desired behaviour are achieved ○ Enables moulding of a response that is not normally part of animal's repertoire

Answer 5

* Behaviour is punished whenever undesirable outcome occurs as a consequence of performing the behaviour * Punished behaviours less likely to be repeated

Answer 6

any consequence of a behaviour that makes the behaviour less likely to recur in future

Answer 7

○ An animal will learn to stop producing a behaviour if consequence for producing behaviour is the presentation of an unpleasant stimulus (adding)

Answer 8

○ Animal will learn to stop producing a behaviour if the consequence of producing that behaviour is that something desirable is taken away (taking away)

Answer 9

○ Three Cs: - Contingency □ Relationship between behaviour and punisher must be clear - Contiguity (timing) □ Punisher must follow behaviour swiftly - Consistency □ Punisher needs to occur for every occurrence of the behaviour

Answer 10

○ Rarely works for long-term behaviour - seems to suppress rather than eliminate ○ Does not teach a more desirable behaviour ○ If the threat of punishment is removed, behaviour returns ○ Produces negative feelings which do not promote new learning ○ Harsh punishment may teach recipient to replicate behaviour towards others

Answer 11

○ Stop reinforcing problem behaviour (extinction) ○ Reinforce and alternative behaviour that is constructive and incompatible with undesired behaviour ○ Reinforce non-occurrence of undesirable behaviour

Answer 12

• About predicting the future from past experience and using these predictions to guide behaviour

Answer 13

○ Need to recognise signals that preempt harmful creature being upon me rather than just the harmful predator itself - Need to predict the future

Answer 14

- Had dogs restrained in Pavlov harness - Measured strength of salivation response in response to food stimuli - Dogs started to predict when he was coming and started to salivate before he showed food

Answer 15

• Conditioning = associative learning ○ Important to learn associations between stimuli in the environment that reliably predict other stimuli ○ Especially in relation to survival

Answer 16

○ Learning an association between a stimulus that reliably predicts another stimulus that is naturally associated with a defensive or appetitive reflex response - Learning to produce a reflex response to a stimulus that would not naturally cause it

Answer 17

• Before conditioning: ○ Unconditioned stimulus (UCS) and unconditioned response (UCR) = reflex - Unlearned - Shown a treat --> salivate ○ A stimulus that does not produce a reflex = neutral stimulus (NS) • During conditioning ○ Preceding UCS with NS to get UCR ○ Establishing conditioned response ○ Need to do NS before UCS so that NS predicts the UCS ○ Repeat a few trials in one session, and again after a delay (days, a week) • After conditioning ○ NS alone gets CR (conditioned response) ○ Reflex salivation response occurs at presentation of formerly neutral stimulus on its own ○ NS becomes CS (conditioned stimulus) ○ UCR becomes CR

Answer 18

Classically conditioned response will generalise to other similar stimuli

Answer 19

- the extinction of stimulus generalisation | - eg Ring a number of other bells and not provide a UCS as well as the one bell that does

Answer 20

○ Keep giving NS but without giving UCS | ○ Learning remains but becomes suppressed

Answer 21

○ Classically conditioned response can return after extinction ○ If there is a rest period after extinction trials and then present the stimulus again, conditioned response will return ○ Extinction will be stronger if extinction trials are spaced over multiple sessions ○ Each time the spontaneously recovered response will be decreased

Answer 22

○ Teaching the subject the CR again after sustained extinction ○ Quickly relearn the response in fewer trials than initially needed - Learning was never fully lost

Answer 23

○ Said you could train infants to become any type of specialist you might choose - Nature dominates over nurture

Answer 24

○ Testing to see if they could induce a phobia in an infant by conditioning a fear response to a rat ○ After the instances they elicited an extreme fear response to the white rat ○ Generalisation occurred to other furry animals and Santa's white beard that he had not previously shown feared in ○ Did not get to extinguish the fear ○ NS --> CS = rat ○ UCS = loud noise ○ UCR = startle response ○ CR = fear of rat

Answer 25

○ Believed cognitive processes played important role in learning complex behaviours, even in non-human animals ○ Against hard-core behaviourism

Answer 26

- Food at end of maze - Number of obstructions in maze that mouse needs to make it past - If it makes wrong decision - punished - Right decision will be rewarded - After number of days rat knows how to run through maze most efficiently making minimal mistakes - Didn't just learn pathways that were rewarded, but also learned mental representation of maze (cognitive map) they would draw upon to get to the food □ Sometimes rat would misbehave - learned much more about spatial environment than what were rewarded paths

Answer 27

- Altered the maze - sunburst maze (more pathways, and the original pathway does not lead to food anymore - Which is the most likely path for rat to run down in new maze? □ Most rats rans down alley 6 when they found out that their original one had no food (brings them out right where food would have been)

Answer 28

- Learning can occur in absence of rewards and punishments

Answer 29

□ Group A was left to explore maze without reinforcement for 20 days □ Group B was left for 10 days and then after 10 days was reinforced, □ Group C was always reinforced □ Learning becomes evident for Group B at day 11 - errors drops as soon as reinforcement was introduced, and mistakes made on day 12 was same as group C □ Learning of group B was latent - couldn't see it (it's not that the rats hadn't learned anything about the maze before reinforcement, but we just couldn't see it because they had no reason to demonstrate it) □ Therefore rewards affect whether learning is demonstrated, not achieved

Answer 30

* Humans and other animals can learn through observing * Observational learning provides another example of how learning can occur indirectly without direct reinforcement or punishment * Learning can take place socially and vicariously (through others) by observing others (models)

Answer 31

○ Observational learning takes place through active judgement and constructive processes not just imitation

Answer 32

○ Experiment investigating children's imitation of aggressive behaviour - Four year-olds watched short film of adult playing aggressively with bobo doll - One group sees adults reinforced with treats after performing aggressive actions - Another group sees adults punished (scolding/spanking by another adult) - Third group saw same film but with no consequence - After film, children played alone in a room with several toys including a bobo doll - When no incentive was given to the kids to imitate the behaviour, those who had seen the rewarding video reproduced same amount of actions as those who saw no consequence, whereas those who saw the punishing video were significantly less likely to reproduce the actions with no incentive - Boys in general were more likely to reproduce the aggressive behaviours than girls - When the children received incentive to reproduce the behaviours, all of them, no matter what video they watched, were equally able to reproduce the behaviours (still with gender difference) - Demonstrated vicarious reinforcement and vicarious punishment - Ties in with latent learning - children only performed the behaviour when reward was present but were much less likely to reproduce the behaviour when there was no reward - reward affects the demonstration of learning rather than the acquisition

Answer 33

- Caused bilateral hippocampal damage - Results in pattern of memory deficits: □ Recall of autobiographic episodes = poor □ Recall of facts learned prior to illness = relatively good □ Capacity to learn new things = poor □ Ability to attend to and understand current conversation = fully preserved □ Musical ability = fully preserved - Despite amnesia still retained his intelligence - No longer had any episodic memory □ Did not have brain parts necessary to recall anything that happened to him his whole life - Could remember general things (semantic memory) □ Knew he was married (semantic) □ Could not remember the wedding (episodic) - Lives in present moment □ Represented by short-term memory and working memory

Answer 34

- Set of systems for encoding, storing, and retrieving information acquired through our senses, and for relating this information to previously acquired knowledge - Mental and neural representation of information we have experienced, imagined, and learned

Answer 35

○ Encoding ○ Retrieval of non-consolidated memory -Retrieval of consolidated memory

Answer 36

- Experience an event (with audio, spatial and visual information) - as we experience that event it sets off activation in the cortex in areas dedicated to receiving that sensory input - Interplay - back-and-forth between the activation occurring in the cortex and the process going on in the hippocampus where each stream of sensory information is being put together into a single representation that matches the input that's occurring - Process of encoding leaves and imprint on brain

Answer 37

- Something causes that event to come to mind - retrieval cue (something that shares some of the same sensory components as original event) - Causes activation of that partial information in hippocampus - Sets off retrieval process that brings to mind other associating information (brings to life connections that have been formed and sends that information back out to the areas of the brain that were originally activated by past experience --> not only the sensory components present in retrieval cue but also other sensory components of original event come to mind - Consolidation occurs through process of retrieval - Storage is strengthened by retrieval

Answer 38

- At point of consolidation of a memory, retrieval cue in environment doesn't need to trigger hippocampus - input is sufficient to regenerate entire network of connections originally experienced - Retrieving can occur either inadvertently - retrieval cue, or with internal intention to retrieve the memory

Answer 39

• Temporary, sensory-based representation of input received through sensory channels ○ First stage of acquisition of sensory input ○ Opportunity for encoding to occur • Allows sensation to persist long enough that we have time to attend to it and store it • Provides buffer ('holding area) between early sensory processes and later cognitive processes • Only some of information stored in sensory memory will be retained • Iconic (visual) and echoic (auditory) memory ○ Brief duration (decays quickly) ○ Large capacity (relative to STM)

Answer 40

○ Letters flash on screen for 50ms - how many can you remember ○ Conclusion of iconic memory capacity - Capacity Is about 4 items ○ Sperling thought method he used was flawed because participants said they could recall everything but it disappeared too quickly to say them all aloud ○ Addressing problem - Modified approach □ Instead of full report of what was seen, asked participants for partial report - Initial set of letters displayed for 50ms - Then auditory tone indicated which line to retrieve from (high tone = top line etc) - Participant repeats cued line □ Findings: - Participants were able to recall most of line cued

Answer 41

-Information goes into sensory register, moves into short-term memory - moves into long-term memory if we rehearse it enough ○ Short-term sits between sensory memory and long-term memory - role is to mediate transformation of sensory input into meaningful content that can be transferred into long-term memory - Thought of as a temporary storage site - structural account ○ Information kept active in short-term memory (STM) through process of active rehearsal mediated by verbal representations ○ Rehearsal results in transfer from STM to LTM (long-term memory) storage site

Answer 42

○ Capacity = 7 +/- 2 items, about the amount of verbal information that can be rehearsed for 2 seconds ○ Duration = seconds to minutes, depending on ability to maintain attention to stimulus

Answer 43

-only gives one-directional flow - doesn't give us a clear mechanism for how information from long-term might be retrieved ○ Need more than just the ability to maintain sensory input to get into long-term memory - need to integrate information that is currently active in consciousness with things from cognitive past

Answer 44

Digit-scan task

Answer 45

○ Recall random sequence of verbally presented digits in the order they were present - Test of immediate serial recall ○ Systematically increased length of sequence to determine the span ○ Average span is 7 +/- 2

Answer 46

overestimates pure short-term memory although useful measure of verbal memory capacity

Answer 47

• Change-detection task

Answer 48

○ Briefly displays a sample array ○ After a brief retention interval (small break) a test array is presented ○ Participants compare the test array with their memory representation of the sample array to determine if there are any differences ○ Results showed that if the size of the sample array changed while the time of the retention interval remained the same, participants could readily make stable judgements about test array up to about 3 or 4 items - then performance accuracy gets worse rapidly

Answer 49

-a strategy to group the input events, apply a new name to the group, then remember the new name rather than the original input events ○ Don't merely retain information but try and make sense of it • Capacity limit on STM should be viewed in relation to the number of meaningful chunks rather than meaningless bits of information • Method that can be used to increase our STM capacity by chunking in groups of 3 or 4 - compatible with capacity of STM • Recent studies that reduce the potential for chunking estimate the pure capacity of STM at 3 +/- 1 units of information rather than 7

Answer 50

○ Remember three consonants ○ To prevent rehearsal - required to count backwards in 3's until given a signal to stop ○ Retention interval was manipulated systematically ○ Memory probed (tested) after 3, 6, 9, 12, 15 or 18 seconds ○ Ability to retrieve three letters in their order dropped rapidly ○ After 3 seconds - participants got the letters right on about 50% of trials ○ By 9 seconds performance dropped to about 20% ○ By 12-18 seconds performance dropped to 0 ○ Suggests memory trace seems to fade half strength after 3 seconds and down to nothing after 12-18

Answer 51

- Forgetting occurred due to interference □ Retroactive interference from subsequently attending to the backwards counting task □ Proactive interference from consonant strings studied on previous trials - Even after 12-18 seconds on first few tasks results were quite accurate - only got worse the more trials done

Answer 52

- Three-part model - Working memory is multi-component model of short-term memory that expands on original idea of multi-component model - Top-tier = central executive process - connects to subsidiary systems: - visuospatial sketchpad - Phonological loop - Episodic buffer - all fluid systems

Answer 53

- Previous accounts left this part out - Images and spatial representations ○ Visuo-spatial working memory system temporarily holds visually based representations such as faces, objects, and written words - Mentally manipulate visual information □ Mental rotation of objects □ The use of mnemonics □ Mental arithmetic □ Cognitive maps for navigation

Answer 54

- Attkinson-Schiffman's model of short-term memory - Verbal memory processes and mechanism of maintenance rehearsal for verbally-coded representations of memory - Capacity for amplifying verbal and sound input and retaining that input through a loop/rehearsal mechanism ○ Working memory involves not just maintenance of information in a phonological store, but active manipulation of the information ○ digit-span backwards task - Considered a test of phonological working memory □ Need to not only hold in mind the number sequences in order, but then also present them backwards - manipulation - In contrast to standard digit-span task which measures maintenance only and does not nvolve manipulation

Answer 55

- Combines information from visuospatial sketchpad and phonological loop together into a bound representation - Combined in multisensory episodic trace - Workspace and experience we have of consciousness - sound and vision work together to give integrated experience - Holds integrated episodes and it's a buffer in that it provides a temporary place for representing the current contents of consciousness

Answer 56

- attentional processes - Higher-level control system that allows us to focus attention on any of the representation areas (the subsidiary systems), and ability to do so simultaneously ○ Executive processes are used in planning and coordinating complex behaviour (attentional system not memory system) - Goal orientation - Focus attention - Control of social behaviour - Switching between tasks, updating memory, inhibition of distracting information - Planning and problem solving ○ Executive processes are governed by circuitry in the pre-frontal cortex

Answer 57

Pre-frontal cortex networks

Answer 58

left-hemisphere fronto-temporal lobe network

Answer 59

right occipital-parietal network

Answer 60

parietal network

Answer 61

- Declarative memory (explicit) | - Non-declarative memory (implicit)

Answer 62

``` ○ Knowing what, why, when, where ○ all of the information that we can talk about ○ Facts, events, locations, ○ Hippocampal-dependent ○ 2 Sub-divisions - Episodic □ Remember personally-experienced events □ Contextualised □ Ability to mentally time travel □ When/where memories □ Tulving - said it is particularly human - Semantic □ What/why □ Abstract □ General knowledge about the world □ Not personal □ Conceptual knowledge ○ Type of declaritive memory can be revealed through explicit memory tests ```

Answer 63

○ Knowing how ○ Motor skills (eg riding a bike) ○ Cognitive skills (eg reading) ○ Non-hippocampal dependent ○ This kind of memory is revealed when previous experience facilitates (improves) performance on a task - Reveals itself through behaviour ○ Does not require conscious recollection ○ Type of memory is revealed through implicit memory tests ○ 5 Subdivisions: - Procedural memory □ Ability to learn and perform motor and cognitive skills ('how to' memory) - Priming □ Demonstrated by change in ability to identify a stimulus as a result of prior exposure to that stimulus or a related stimulus □ Repetition priming - For example, prior exposure to a word in a lexical decision task will make the word easier to respond to the next time it is encountered □ Associative/semantic priming - Example - the prior presentation of the word 'nurse' facilitates subsequent identification of the word 'doctor' - Classical conditioning (associative learning) □ Learning to attend a neutral stimulus because it has become associated with a meaningful stimulus - Operant conditioning (associative learning) □ Learning to produce/avoid a behaviour because it has become associated with rewarding/punishing consequences - Non-associative learning □ Habituation - Earning to ignore a stimulus because it is trivial (eg screening out background noise) □ Sensitisation - Learning to attend to a potentially threatening stimulus

Answer 64

• Deficits in memory caused by brain damage, disease, drug abuse, or psychological trauma • The selective deficits in memory processes seen in cases of amnesia provide support for the proposed division between the declarative and non-declarative memory systems -Two types: -retrograde -anterograde

Answer 65

○ Inability to recall things that happened prior to problem causing the amnesia ○ Usually temporally graded - Oldest memories are less susceptible to amnesia - Temporal gradient - *Clive Wearing did not have a temporal gradient - did not remember any of it* ○ Usually rare or temporary

Answer 66

○ An inability to recall anything since the time of the brain injury ○ Inability to learn new information ○ Much more common

Answer 67

• Developed severe epileptic seizures in his youth ○ Rendered him unconscious every time • Through teens and early 20s seizures became more frequent • Experimental surgery proposed to treat the seizures ○ Removal of the medial portion of both temporal lobes, including hippocampi • H.M. acquired a severe and permanent inability to acquire any new information ○ Both episodic and semantic ○ Anterograde amnesia • very precise damage to brain - precision of surgeon's knife rather than general damage ○ Very pure case of what happens when the medial temporal structures are removed • Did stop seizures • Experienced both retrograde and anterograde amnesia ○ Retrograde: - Couldn't remember hospital staff or his way to the bathroom - Did not remember death of favourite uncle three years previously - But early memories vivid and intact (temporal gradient) ○ Severe Anterograde: - Could recall nothing of his day-to-day events of his hospital life - Could not form, retain, or retrieve new episodic memories - Severely impaired ability to learn new semantic facts • Normal sensory and working memory (STM) ○ Normal digit span ability

Answer 68

Said they were merely outcomes of the normal processes of perceiving and comprehension • Brenda Milner challenged this: ○ Her amnesic patients had no trouble comprehending events, they were clearly capable of processing deep semantic levels, but they don't remember things - How can that be explained by Craik's theory?

Answer 69

* The temporal gradient of retrograde amnesia tells us that memories cannot be stored permanently in the hippocampi * Severe anterograde amnesia that results from the removal of the hippocampi bilaterally indicates that these structures must be crucial for the consolidation of new information * Craik conceded that cases like H.M. forced him to adjust his account of elaborative encoding to include not just the process of interacting meaningfully with information in working memory, but also an additional process of consolidation, mediated by the hippocampus * Memory can be fully consolidated at the point at which it can be retrieved through cueing where memories are now independent of hippocampus and can self-activate in their own network

Answer 70

no: ○ Concurrent performance of a visuo-spatial task and a phonological recall task does not impair the performance on either task - Eg a visuospatial task such as recalling the pattern of coloured squares on a checkerboard does not interfere with verbal digit-span task ○ Operate independently from one another ○ Two tasks of the same nature (ie two phonological loop or two visuo-spatial sketchpad tasks) when performed together will have interference ○ Contrast with the effect of non-attended speech in the auditory channel while trying to complete an auditory memory task - the non-attended speech effect occurs when performance on a verbal memory task declines in the presence of irrelevant speech

Answer 71

○ Given piece of paper with double-outline of a star on it ○ Need to trace a third line in between the two lines trying not to take new line outside boundaries of other two ○ Do this with a barrier up so you can't directly see what hands are doing - only have a mirror to reference your performance ○ Need to adapt to following movements of your hands mirror-reversed ○ Difficult to do the first time but will adapt with practice ○ Would H.M. show equivalent mirror tracing performance if he practiced the task over a few days? - Despite thinking he had never done the task before, his results did show improvement over time - Showed completely normal acquisition of the skill - Demonstrates that procedural learning can proceed independently of the brain systems required for declarative memories - First evidence of a clear dissociation between devastated declarative memory ability and his fully preserved non-declarative performance

Answer 72

○ Intact classical conditioning ○ Intact priming effects seen in word-stem completion tasks ○ Normal habituation and sensitisation • Both H.M. and Wearing show these effects • Also patients with Korsakoff's syndrome (anterograde amnesia caused by binge-drinking), depressed patients undergoing bilateral ECT, patients with anoxic encephalopathy who all suffer anterograde amnesia

Answer 73

The ability to preferentially process some parts of stimulus at the expense of processing other parts of the stimulus

Answer 74

○ Perceptual system has limited capacity ○ Can't process everything in visual scene simultaneously - Helps us avoid becoming overwhelmed by limiting processing

Answer 75

Overt attention | Covert attention

Answer 76

Looking directly at an object

Answer 77

- looking at one object but attending to other objects | ○ Could be used in sports to make people think they are going to move one way but actually move another way

Answer 78

Tracking eye movements | -Unless purposely try not to, you generally look at the object to which you attend

Answer 79

saccades • Eyes do not move over scene smoothly - they jump from point to point Jumps are known as saccades

Answer 80

Rests between the eye jumps where eyes stay looking directly at object

Answer 81

Your goals and expectations

Answer 82

Ballistically (fast)

Answer 83

○ Initial involuntary process (mediated by attentional capture) ○ Subsequent voluntary process (guided by goals and expectations)

Answer 84

• When scene is first presented fixations are captured by salient parts of a scene ○ Known as 'attentional capture' - involuntary • After first few fixations can then direct your fixations according to your goals ○ Voluntary

Answer 85

○ Contrast - Regions of colour contrast or luminance contrast - Regions of size contrast - Regions of orientation contrast - Regions of motion/flicker contrast

Answer 86

○ Observer's goals and expectations - If an object is unexpected you will fixate on it longer and more often □ Syntactically inconsistent = an expected object doing something unexpected (something that violates the fundamental laws of nature) □ Semantically inconsistent = unexpected object

Answer 87

-Attention speeds responses -Can influence appearance • Attention can change apparent contrast of an object • Attention can also make objects appear bigger, faster, more richly coloured • Makes perception more vivid -Can influence physiological responding

Answer 88

○ Shown a box with an arrow above it to indicate which side an 'X would appear on ○ Valid trials = X appeared on side indicated by arrow ○ Invalid trials = X appeared on other side than implied by arrow ○ Neutral trials = no arrow appeared ○ Participants had to press button as soon as X appeared (only had to respond to indicate the X appeared, not on which side it appeared on) ○ Found that Invalid trials produced the slowest response times

Answer 89

- Participants were shown two gratings of different contrast and had to record which one had higher contrast - Sometimes there was a peripheral cue (a dot drawing the attention to one side) - When there was a peripheral cue and the contrasts were the same participants recorded the grating on the side of the cue to be of a higher contrast - Suggests that cued grating appeared to be higher contrast

Answer 90

Neurons in the brain respond more strongly to attended stimuli than to unattended stimuli

Answer 91

The issue of how an object's individual features are combined (bound) to create a coherent percept is known as the binding problem

Answer 92

○ Suggests that binding problem is solved by attending to only one location at a time ○ Crucially, only features associated with that location are processed - only these features are bound together ○ This avoids binding features from different objects

Answer 93

○ A prediction of FIT is that if attention is inhibited features from different objects will be incorrectly bound together ○ Treisman and Schmidt - illusory conjunctions occur - Presented character strings very briefly (95-168ms) followed by a noise mask - Primary task was to report the two numbers - Observers were asked to report coloured letters - Observers often associated the wrong colour with the wrong letter - Incorrect bindings = illusory conjunctions

Answer 94

○ RM is a patient with parietal lobe damage ○ Has Balint's syndrome ○ When multiple objects are present, RM has difficulty focusing attention on a single object ○ When shown two letters, each with a different colour, reported the wrong letter-colour combinations on 23% of trials, even when allowed to view the letters for 10 seconds ○ RM is very prone to illusory conjunctions because he could not focus attention on single object

Answer 95

○ Some forms of visual search require binding to occur ○ Eg binding is required is the target contains the same features as the distractors ○ If the target differs from the distractors only by its particular conjunctions of features - conjunction search ○ FIT predicts that in conjunction searches attention needs to be applied to each object in turn (one at a time) to determine whether or not the attended object is the target ○ These searches are predicted to be very slow ○ Other types of visual search can occur without solving the binding problem ○ If the target contains a feature that the distractors do not - feature search ○ FIT predicts that because binding does not need to occur, attention does not need to be applied to each item in turn - Searches are predicted to be fast

Answer 96

• Attention can determine what we remember • If you don't attend to it , you probably won't remember it • Change blindness = changes that are obvious when attention is drawn to them and are missed when attention is not drawn to them • You can only notice a few parts of a scene at a time • If one of those parts change you will notice it • If another part of the scene changes you will not notice it • Doesn't only happen in static pictures - can also happen in real world ○ Simons and Levin - Experimenter asks someone on the street for directions - People carry a door pass between them and the experimenter changes - 50% of people giving directions did not notice the change in person

Answer 97

-Stimulus on the retina is ambiguous ○ Objects can be hidden or blurred - Machines have difficulty recognising objects if the whole object is not seen or is blurry ○ Objects look different from different viewpoints and in different poses - Machines find it hard to recognise an object when they appear in unexpected poses or angles

Answer 98

- Structuralism | - Gestaltism

Answer 99

○ Distinguishes between sensations and perceptions ○ Sensations = elementary processes occurin response to stimulation ○ Perceptions= = conscious awareness of objects and scenes ○ Structuralism claims that sensations combine to form perceptions ○ According to structuralism conscious awareness is sum of these elementary sensations § Contains nothing that was not already present in these elementary sensations

Answer 100

○ Directly contradicts structuralism ○ Conscious awareness is more than just the sum of the elementary sensations ○ Conscious awareness can have a characteristic not present in any of the elementary sensations ○ Two pieces of evidence for this claim: - Apparent motion □ Observer sees two stationary dots flashed in succession □ Although each dot is stationary observer sees motion □ Conscious awareness has a character (motion) not present in elementary sensations □ Conscious percept of motion was constructed and was not present n the elementary sensations - Illusionary contours □ Seen in locations where there are no physical contours □ Conscious awareness of the illusory contour is constructed

Answer 101

-Grouping □ Process by which parts of an image are perceptually bound together to form the perceptual whole -Segregation □ Process by which parts of a scene are perceptually separate to form separate wholes/objects -Together, grouping and segregation allow a scene to be perceptually organised into its constituent objects thereby allowing observers to make sense of the scene

Answer 102

• The more of these principles that apply, the more likely components of an image will be grouped together to form a perceptual object • Original principles ○ Good continuation - Aligned or nearly aligned contours are grouped together to form a single object ○ Pragnaz - AKA principle of good simplicity - Essentially groupings occur to make the resultant figure as simple as possible ○ Similarity - The more similar objects are, the more likely they will be grouped together ○ Proximity - The closer objects are together the more likely they will be grouped together ○ Common fate - Things that move together are grouped together • Additional 2: ○ Common region - Elements that are in the same region of space are grouped together ○ Uniform connectedness - Connected regions with the same visual characteristics (eg colour) tend to group together

Answer 103

• Much of perceptual literature focuses on figure-ground segregation • Objects are normally perceived as figures and the background is typically perceived as the ground • If you can identify the figure you can identify the objects • Regions of image are more likely to be seen as the figure if: ○ They are in front of the rest of the image ○ They are at the bottom of the image ○ They are convex ○ They are recognisable • The more factors that combine, the more likely that it will be seen as a figure

Answer 104

• When scenes are flashed rapidly in front of an observer, she may not be able to identify all the objects in the scene • But she will get an overall impression of what the scene is about ○ Gist of the scene • Potter - studied gist perception ○ In each trial the observer was cued with a particular scene description ○ Then she saw 16 randomly chosen scenes each for 250 ms ○ Was asked if any of the scenes fitted the description ○ Observers were at ear 100% accuracy ○ Showed that observers can rapidly perceive a scene's gist • Fei Fei investigated what the minimum scene exposure time is need to perceive a scene's gist ○ Observers were presented with just one scene followed by a mask ○ Were then asked to describe what they had seen ○ Reported that the longer the stimulus presentation time, the more detailed and accurate the description ○ People could start to perceive aspects of the scene at about 27ms but perceptions were not very detailed

Answer 105

``` ○ Break camouflage ○ Attract attention ○ Segregate objects from their backgrounds ○ Interpret events ○ Determine the structure of objects ○ Determine what actions people are performing ```

Answer 106

○ A camouflaged animal can be virtually invisible until it moves ○ When it moves the camouflage is broken and it attracts attention ○ It also helps us segregate the animal from the background

Answer 107

○ Can infer causality relationships and social relationships by seeing how objects interact

Answer 108

○ Can help us determine the shape of a moving object | § Kinetic depth effect

Answer 109

○ Static poses are often ambiguous, but when someone moves their actions and intentions are often made clear - Demonstrated using point-light walkers □ Placing lights on a person's joints and getting them to do actions □ Videoed so only the lights can be seen □ Humans are so good at processing motion stimulii they can often guess what action the person was doing

Answer 110

Akinetopsia

Answer 111

``` ○ Pouring cup of tea § Can't tell when it will overflow ○ Crossing street § Can't tell whether cars are moving ○ Following speech § Trouble detecting motion of the mouth • Examples in every day life Ship on horizon is too far away to detect the motion ```

Answer 112

-When there is real motion -When nothing is moving (illusory motion) • Motion aftereffects • Induced motion

Answer 113

○ Static image - Rotating snake illusion (concentric circles that appear to rotate even htough they're stationary) - Don't know why it appears to move - Percept of motion is caused by contrast of the colours ○ Apparent motion - Series of stationary images presented in succession to give impression of motion - Eg two dots flashing gives impression of one dot moving between the points - Only works if dots are lose together - If alternation rate is too fast, motion perception does not occur - For it to occur, as separation increases, alternation rate needs to decrease - Known as Korte's Third Law of Apparent Motion - Mostly insensitive to colour changes - But colour can still be used to disambiguate ambiguous motion (eg if two of the same objects are different colours and flash to different positions, you will see their motion separately)

Answer 114

○ Waterfall illusion: § After staring at a waterfall for several minutes, then looking at the stationary rockface, the rockface will appear to move upwards

Answer 115

○ Moving background (or object) causes stationary object to appear to move

Answer 116

The effect of motion making things seem to disappear

Answer 117

○ Motion induced change blindness ○ Normally colour changes attract attention because of transient signals associated with the change ○ When things are moving, there are transient signals associated with all objects not just the ones changing ○ Attention is no longer drawn preferentially to the changing objects so changes are not noticed

Answer 118

can inform us of the process underlying motion perception

Answer 119

○ Yellow and blue rectangle placed with yellow above blow in front of black and white lines ○ As they cross the lines, the rectangles appear to take it in turns speeding up and slowing down when looking at the focus crosses ○ Happens because when end of yellow rectangle is over the white line, contrast at the leading edge is low and the contrast of the leading blue edge is high ○ When end of yellow is on black contrast with the leading edge is high and contrast with the leading blue edge is low ○ When one has low contrast, the other has low contrast ○ When contrast is high they appear to move faster ○ Shows that contrast affects motion perception

Answer 120

○ If you can't see end of a line the movement of the line is ambiguous ○ Consequently, if the ends of a line are hidden by an 'aperture' the motion of the line is determine by the terminators (the points at which the line meets the aperture) ○ When terminators move horizontally, line appears to move horizontally, when they move vertically the line appears to move vertically

Answer 121

○ Aperture problem applies ○ Lines curve around a cylinder creating virtual terminators that move vertically ○ Lines themselves appear to move vertically

Answer 122

* Suggested that colour vision evolved to help humans find things * Can also help make judgements * And poisonous animals * And to attract mates

Answer 123

electromagnetic radiation with wavelengths varying 400nm - 700nm

Answer 124

Light cannot pass through it, its colour is determined by the colour it reflects

Answer 125

Determined by the colour it transmits (ie that passes through it)

Answer 126

○ Blue paint absorbs red light but reflects blue and green light ○ Yellow paint absorbs blue light but reflects red and green light ○ Mixing blue and yellow results in a mixture absorbing both red and blue light but reflects green light - looks green

Answer 127

○ Mixing red and green makes yellow light | ○ Mixing blue and yellow light - get white (because it contains blue green and red)

Answer 128

○ Hue (colour) ○ Value (lightness) Chroma (saturation)

Answer 129

• In retina - photoreceptors called rods and cones • Rods cannot distinguish between colours - active only at low-light levels • Three types of cones (each type responds to different wavelengths) ○ S cones (419nm) - blue --> short wavelengths ○ M cones (531nm) - green --> medium wavelengths ○ L cones (558nm) - red --> large wavelengths • By comparing the relative activities of these three types of cones humans can distinguish between colours • If L cone is most active - mainly see red

Answer 130

○ Because we only have 3 cones any coloured ligth can be made using the three lights - red, blue, green ○ Even though two patches of light may not have same spectral composition, they will appear to have the same colour ○ Physically different stimuli that appear the same are called metamers

Answer 131

○ Monochromatism | ○ Dichromatism

Answer 132

§ Affects about 1 in 100 000 people § Usually have no functioning cones § Only functioning rods § Truly colour blind - see the world in shades of grey § Very sensitive to light - need dark glasses during the day

Answer 133

- Lacking of the three types of cones - Three types of dichromatism □ Protanopia - Lack L cones - Cannot distinguish red and green - 1% males - 0.02% females □ Deuteranopia - Lack M cones -Cannot distinguish red and green - 1% males - 0.01% females □ Tritanopia - Lack S cones - Cannot distinguish blue and green - 0.002% males - 0.001% females - Because dichromats lack a cone type, for their perception it is possible to match a patch of any coloured light using just two lights - Unilateral dichromats - normal vision in one eye and dichromatic vision in the other □ Can give an insight as to what dichromats see in comparison to normal vision □ Protanopes and Deuteranopes (cannot distinguish between red and green) see world in shades of blue and yellowish green □ Tritanopes see the world in shades of blue and red

Answer 134

• Doesn't replace trichromatic theory, merely supplements it • What colour we perceive is not only determined by cones in our retina ○ Singals from these cones are processed by the cortex where they are combined into three colour opponent channels § Red-green § Blue-yellow § White-black

Answer 135

- After images □ When you stare at a colour for a while (eg red), that colour's processing channel will get fatigued and the opposite colour in the colour channel (green) can be more active to compensate - causing you to see green where there was red □ Evidence that colour channels exist - Impossible colours □ Some colour combinations are impossible □ Can have bluish red (purple) and yellowish red (orange), yellowish green and bluish green □ Can't have redish green or bluish yellow □ Adding blue to yellow light - becomes green not bluish yellow □ Adding red to green light - becomes yellow not reddish green □ These colours are impossible because they are opponent colours

Answer 136

• The colour light an object reflects is determined not only by its reflectance but also by the colour of the light shining on it • If white is shone on a green jumper, green jumper will predominantly reflect green light • But if light shone on jumper is red then the jumper will appear predominantly red because the jumper will reflect predominantly red light • Even though green objects absorbe red light, if you shine enough red light on it it will reflect some • If you only shine red light on it it can only reflect red light • Light reflected by an object is determined by the product of its reflectance and the illumination • Why do we continue to see a green jumper even when it is reflecting red? ○ We habituate the colour ○ If entire scene is under red light we habituate to red so everything appears greener than it otherwise would ○ Habituation is not large enough to explain colour constancy • There are at least two ways of achieving colour constancy: ○ Habituation ○ Discounting the illuminant

Answer 137

○ Cues to do with the eyes ○ Where are the eyes focussed ○ How have they accommodated ○ Cues based on our ability to sense the position of our eyes

Answer 138

- Binocular convergence □ Objects that are close to face make eyes converge (cross-eye) □ By estimating the degree of convergence you can estimate how far away an object is - Accomodation □ Lens changing shape to focus on an object depending on how close/far away it is

Answer 139

Oculomotor cues Monocular cues Binocular cues

Answer 140

○ Cues that you can pick up with one eye shut

Answer 141

Accommodation Pictorial cues Movement-based cues

Answer 142

□ 7 types - Occlusion ◊ Something behind partially hidden by another (eg when it is behind) - Relative height - Familiar and relative size - Perspective convergence ◊ Parallel lines appear to converge - Atmospheric perspective ◊ Degree to which an atmosphere obscures something gives and indication for how far away it is - Texture gradient ◊ Things close up can bee seen in detail - Shadows ◊ Humans assume light comes from above, so if a shape is lit from above and shaded from the bottom it looks like it comes out, but if it is shaded from the top it looks like It goes in

Answer 143

□ Motion parallax - Objects closer to a moving train (when looking out from a train) appear to move faster than those far away - Because closer objects require retina to move more than objects further away when moving the same distance □ Deletion and accretion - Some things pass and some things appear when moving - the rate of deletion/accretion gives and idea for how far away they are

Answer 144

○ But point of fixation does affect absolute disparity ○ Whichever object is being fixated on falls at the centre of the left and right retinas ○ Therefore left and right images of the object fall onto corresponding parts of the retina ○ All objects that lie on the horopter fall on corresponding parts of the retina § Horopter = a plane containing all the points that will fall on corresponding parts of the two retinas) ○ In front of horopter = appears to the right of horopter in left eye, and left of horopter in right eye ○ Behind horopter = appears to the left of horopter in left eye view, right of horopter in right eye view

Answer 145

* Retinal images can be ambiguous * If there are multiple identitcal objects in the scene it can be hard to figure out which images in the left retinal image should be associated with which images on the right retinal image * This is known as the correspondence problem

Answer 146

Size constancy | Size illusions

Answer 147

○ The phenomenon where an object's apparent size does not depend on its physical distance ○ When an object is far away it appears to be the same size when it is closer even though visual angle is much larger in the latter ○ To achieve size constancy the observer needs to consider both the size of the retinal image and the distance of the object ○ S = K ( R x D ) - Where S = apparent size of and object, K is a constant, R is the size of the retinal image, D is the distance to the object -Two factors -Angular size -Visual angle and object subtends -The closer and object is to a person the larger its angualr size - Perceived depth

Answer 148

○ Most size illusions are caused by causing people to mistake the distance to an object so that it appears larger or smaller than it actually is ○ If an object appears closer than it really is, it will appear smaller than it really is and the vice versa

Answer 149

○ Investigated how observers accurately estimate the size of objects ○ In particular how depth cues can affect size judgements - Observers sat in intersection of 2 corridors, and could view a test circle in one corridor and a comparison circle in another - Task was to adjust the size of the comparison circle to match the size of the test circle - Test circles were different sizes but were presented at different distances so their angular size was always the same - In condition 1, they could determine the depth of the test patch using binocular disparity, motion parallax and shadows - In condition 2 observers viewed the test circle with one eye to remove binocular disparity cues - In condition 3 observers viewed the test circle through a peephole to remove motion parallax cues - Condition 4 - in addition to viewing circle through a peephole, drapes were used to remove shadows - Found that condition 1 estimated the actual size of the test circle relatively well (albeit slightly overcompensating), condition 2 also very accurate at guessing the test circle size, condition 3 had great difficulty estimating the actual size, and condition 4 misperceived the size (underestimating) even more ○ Therefore, when there are sufficient depth cues, the size of the test patch can be accurately estimated, but when there are insufficient depth cues, apparent size of test patch is biased towards visual angle

Answer 150

sound is pressure changes in the air or other medium

Answer 151

sound is the experience we have when we hear

Answer 152

○ Pressure waves move through the air at 340m/s and 1500m/s in water ○ However only the pressure wave is moving ○ Each air molecule is oscillating in place to create regions of high and low pressure

Answer 153

○ A pure tone occurs when the pressure change follows a sine wave

Answer 154

○ The higher the frequency the higher the pitch ○ 1 Hz = 1 oscillation per second ○ Humans can hear frequencies ranging from around 20 Hz to about 20 000Hz

Answer 155

○ The greater the amplitude, the louder the sound seems ○ Measured in decibels (dB) ○ dB= 20 x logarithm(pressure change/reference pressure) ○ Reference pressure is usually set to 20 micropascals

Answer 156

○ Combination of different-frequency sine waves ○ The 200Hz frequency is known as the fundamental frequency and is also known as the first harmonic ○ 400 Hz = second harmonic ○ 600 Hz = third harmonic ○ 800Hz = fourth harmonic ○ Because the first harmonic is 200Hz, this means that the wave repeats every 5 ms

Answer 157

• The greater the amplitude, the louder it seems • However, the actual loudness depends on the frequency • Perceptual loudness is is measured in phons ○ Units of loudness for pure tones ○ Can't measure with a machine • Loudness is also determined by frequency - a sound with frequency of 800Hz will sound louder than a sound with the same amplitude and a frequency either lower or higher ○ More sensitive to frequencies at about 800Hz

Answer 158

-perceptual aspect of sound ○ For a pure tone, pitch is determined by a frequency ○ For a complex tone, pitch is usually determined by the fundamental frequency - Pitch is a psychological quantity, not a physical quantity so it depends on a number of factors - Cannot describe pitch in terms of Hz, instead assign musical notes ○ All notes of the same musical letter are a multiple of the same frequency - They sound similar □ Have the same chroma - Tone height increases as one moves from left to right on a piano keyboard ○ Pitch has two variables - Chroma □ Cyclic in that neighbouring letters of the same type sound similar - Tone height

Answer 159

○ For many sounds, their frequency components are multiples of a particular frequency - Fundamental frequency ○ Since all the harmonics are multiples of the first harmonic, they will repeat at 200Hz ○ However, the complex tone will continue to repeat at the fundamental frequency even when the fundamental frequency is absent - Because all the other frequencies of the tone are mutiples of the fundamental frequency - Humans will perceive the presence of the fundamental frequency even when it's not there - 'Missing fundamental' ○ The missing fundamental determines the pitch of a complex tone ○ This is why you can hear over the telephone a man's voice corresponding to 100Hz even though telephones do not produce sounds lower than 300Hz

Answer 160

-part of perceptual aspect of sound ○ When two musical instruments play the same note they do not sound the same - Because in addition to playing the fundamental frequency, each instrument plays many of the harmonics of the fundamental frequency - Amplitude of these harmonics will differ across instruments - Causing different timbres

Answer 161

○ Musical sounds are periodic - meaning the wave forms repeat - Two types □ Simple (single sinewaves) □ Complex (multiple sinewaves)

Answer 162

``` waveforms that don't repeat - Eg door slamming shut/gunshot - Called aperiodic sounds □ Two types - Continuous (noise) - Transient (pulse) ```

Answer 163

* binaural cues - both ears | * monaural cues - one ear

Answer 164

-Interaural time difference -Time difference between sound geting to one ear relative to the other -Interaural level difference -Amplitude of the sound arriving at one each compared with the other -For high frequency sounds there can be a large interaural level difference between the two ears due to the sound shadow caused by the head -For low frequency sounds, the interaural level difference will be much less ○ Cone of confusion - At any two points connected by a circumference line on the surface of this cone have the same difference in distance to the two ears - Thus they will have the same interaural time difference and interaural level difference - So binaural cues cannot be used to distinguish between the two points - need to use monaural cues

Answer 165

○ Sound coming from different directions bounces off different parts of the pinna (outer ear) before entering ear canal ○ Consequently sound acquires characteristic frequency notches that depend on its elevation ○ Can be used to determine the elevation of the source

Answer 166

○ If you hear the same sound twice with a temporal separation of 5-20ms you will not register the second sound ○ However if the temporal separation between the two sounds is more than about a 10th of a second, you will hear the two sounds separately

Answer 167

- Reverberation time □ Time it takes for sound to decrease by 60dB □ For a concert hall it should be about 2 seconds □ For an opera hall ideally it would be around 1.5 seconds to make the voices more distinguishable - Intimacy time □ Temporal difference between when the direct sound arrives and when the first indirect sound arrives □ Concert halls with good acoustics typically have intimacy time of 20ms - Bass ratio □ Measured for indirect sound □ The ratio of low frequencies to middle frequencies for the indirect sound □ Want high bass ratio - Spaciousness factor □ Ratio of indirect sound to total sound □ Greater the proportion of indirect sound the greater the spaciousness factor □ Want a high spaciousness factor

Answer 168

- When concert hall is full, people absorb a lot of sound - If a concert hall is designed to sound very good when it is full it might sound bad when it's empty - Solution: have pillows where each pillow absorbs the same amount of sound as the average person

Answer 169

○ Five cues: - Location □ Because the instruments will not be playing exactly the same notes at exactly the same time, ou will be able to hear that they occupy separate locations □ Make use of interaural level differences □ Very strong cue for segregation □ However, it is not necessary □ Even if all the sound were to come from just one location (eg speaker) you would still be able to segregate the musicians - Onset Time □ If the two sounds start at different times, chances are the originate from different sources □ If two sounds start at the same time they probably come from the same source - Timbre and pitch □ It's easy to segregate musical instruments that have different timbres □ Even instruments with the same timbre an be separated on a basis of pitch - Auditory continuity □ Tones interrupted by silence are heard as distinct □ Tones interrupted by noise are heard as continuous □ Humans assume tones continue through the noise - Experience □ If two melodies are played simultaneously, you are more likely to segregate them if you know the two melodies separately □ Similarly, if you know what a particular person or particular animal sounds like, you are more likely to detect the presence of that as background noise

Answer 170

• 100 billion neurons in the brain - 1 000 000 billion synapses

Answer 171

○ Initially thought heart was seat of the mind ○ Changes to out understanding of the brain were limited by - Religious/moral view - Limited methods - Reliance on chance discoveries - Scientific conservatism

Answer 172

-a disorder of language comprehension ○ Inability to comprehend what was being said to them, but could otherwise prodcue language ○ Lesions in left temporal lobe ○ Implies the two areas need to be used together for language abilities

Answer 173

○ Patients often difficult to test intensively ○ Problem of replicability in single cases ○ Assumption that local lesions have local effects (not true for broca's and Wernicke's area) ○ No control of lesion size or location in the brain (experiments of nature)

Answer 174

-precise localisation of cortical function ○ Fritsch & Hitzig - electrically stimulated different parts of the frontal cortex in a dog ○ Induced contractions of specific muscles on opposite side of the body ○ Surgical removal of these motor regions of the cortex led to impairments of actions performed by the relevant limb ○ Electrical activity was not only sufficient, but necessary for controlling movement

Answer 175

-hippocampus role in memory ○ Deliberate lesions allow a fairly high degree of precision ○ Eg Limbic system contains a number of small structures including hippocampus and amygdala - Ablations in monkeys show only the hippocampus playing a role in learning and memory ○ Recall HM - Bilateral medial temporal lobectomy (removing hippocampus) - Left him densely amnesic

Answer 176

-linked to personality ○ Introduced prefrontal leucotomy (lobotomy) for the relief of psychiatric disorders ○ Surgical procedure was based on reports by Yale researchers that removing the frontal lobes of a chimpanzee made it calmer and more cooperative

Answer 177

``` ○ Initial impression of improvements - Led to widespread use - Subsequently shown to be ineffective ○ Profound personality consequences - Apathy - Emotional unresponsiveness - Disinhibition - Inability to plan ```

Answer 178

○ Popularised by Walter Freeman - Patients did not need to undergo surgical procedur □ Patients would be rendered unconscious by electric shock □ Ice pick placed behind eye against bone at the back of the eye socket □ Ice pick would pierce frontal lobes, and moving it backwards and forwards would sever connections between frontal lobes - 40 000 operations in USA

Answer 179

• Electroconvulsive therapy for treatment of psychiatric illnesses ○ Based on knowledge that seizures seemed to relieve psychiatric symptoms ○ ECT originally used to treat a range of mental illness - Now used to treat severe depression ○ Mechanism of action is unknown - Electrical stimulation of frontal lobes needs to be strong enough to cause seizure • TMS - more causal ○ Generates strong magnetic field which travels down into brain tissue ○ Can alter brain function in specific area of brain under coil ○ Can be used clinically - Disrupts frontal lobe activity to provide relief for people with psychiatric disturbance

Answer 180

○ One of the main diagnostic tests for epilepsy ○ Sign that person is having a seizure: all neurons are firing in a coordinated way - normal brain activity requires different brain modules activated at different times ○ Not clear where brain activity changes are happening across the brain

Answer 181

○ Hodgkin & Huxley - recorded action potentials in giant axon of Atlantic squid ○ A subsequent explosion of research in the following decades was based on technical advancements - Development of microelectrodes - High-gain electronic amplifiers - Oscilloscopes ○ Much of sensory and motor cortex was mapped using these methods in animal studies ○ Hubel and Wiesel mapped the development and functional organisation of the visual system

Answer 182

• Computerised tomographic (CT) scanning reveals brain structures ○ First introduced commercially in 1983 • Magnetic Resonance Imaging (MRI) reveals brain structure ○ 3D computer reconstruction ○ More detail in brain itself than CT ○ MRI physics - Hydrogen is affected by magnetic fields □ Hydrogen has a single proton □ Proton spins around axis □ Axis of spin is usually random □ Axis aligns with magnetic fields □ Introduce a radiofrequency pulse - axis of rotation in every atom moves by the same amount □ Turning off radiofrequency pulse - atoms relax back into alignment with magnetic field - Give off energy which is picked up by detectors in MRI machine □ Tissue that is less dense has more water - large amount of hydrogen - Amount of energy given off is directly related to density of tissue in that part of body

Answer 183

-allow us to look into the functioning of the brain when someone is experiencing functional loss to see if there is a structural correlate of that brain function ○ Can use them in real time - don't need patients to be dead

Answer 184

-functional Magnetic Resonance Imaging (fMRI) ○ Cognitive processes use energy - Production of energy uses oxygen from blood ○ Oxygenated blood - Weakly diamagnetic - Doesn't distort surrounding magnetic field ○ Deoxygenated blood - Paramagnetic - Distort the surrounding magnetic field ○ Blood vessels became more visible as blood oxygen is decreased - BOLD effect ○ Provides fine spatial detail - can locate activity relatively well ○ Takes a long time though - not very good for resolving quick changes in brain activity

Answer 185

-reflects anticipated brain activity ○ Dominates fMRI studies that map human brain funciton ○ When brain is about to become active - oversupply of oxygenated blood in anticipation that the brain is going to need more oxygen to support the activity ○ Neurons can't use up all of the oxygenated blood as it would at rest - see an increase of oxygenated blood relative to deoxygenated blood - BOLD effect

Answer 186

○ While they do provide some correlation between brain activity in one part of the brain and cognitive function, doesn't necessarily prove causality - Why we use TMS: can infer causality

Answer 187

- behaviour that doesn't need conscious thought | • Purpose: to respond quickly to something potentially damaging to us

Answer 188

○ Axon of sensory neuron (conscious signal of pain - eg when you touch something hot) ○ signal is carried from receptors back through the limb to a neuron that projects into the spinal cord ○ some signals go out from the spinal cord to the brain (we know from the conscious experience of heat), but the semata-sensory neuron comes into close proximity with an interneuron in the spinal cord itself ○ if there is enough activity in the semata-sensory neuron, it will excite the interneuron ○ interneuron then comes into close proximity with a motor neuron at the same level of the spinal cord ○ axon of this neuron projects out forming synapses on the limb's muscle ○ if motor neuron is excited it causes a release of the chemical (neurotransmitter) onto muscle fibre ○ If that happens, muscle contracts - causing withdrawal from source of pain

Answer 189

○ We know that signals get up to cortex because we have conscious experience of pain ○ We might be able to use current knowledge of situation to influence activity of motor neuron ○ If we don't want to drop something - opportunity for signal to descend back from cortex down through spinal cord ○ That signal could come down from an axon from a neuron in the brain and excite an interneuron at same level in spinal cord ○ While other interneuron might excite the motor neuron, this interneuron might inhibit it - Whether or not motor neuron fires might depend on level of excitation coming through semato- sensory neuron through the withdrawal pathway and the amount of excitation coming down from axon in the brain with an inhibitory influence - More excitation coming through withdrawal reflex - firing of motor neuron and withdrawal from source of pain - If inhibitory effect is stronger, will not withdraw from source of pain

Answer 190

- Signal originates from axon hillock - Myelin sheath are needed to electrical signal doesn't leak out - Mitochondria - responsible for releasing a chemical that's used as energy within the cell

Answer 191

- Comprised of lipid sheath □ Physically separates fluid inside neuron from fluid outside neuron □ Also provides electrical insulation between the two fluids

Answer 192

- Provide physical support (astrocyte) - Assist with chemical transport to and from neurons (oligodendrocyte and schwann cell) - Provide insulation - Destroy and remove neurons that have died from injury or old age (microglia) - Oligodendrocyte found in central nervous system, schwann cells found in peripheral nervous system - Microglia - also play role in inflammatory responses in infection in the brain

Answer 193

- Small electrodes can be inserted into cell body of neurons - If there is another electrode in the extracellular space, can connect both electrodes to an amplifier and measure the voltage difference between inside and outside of cell - Sending signal to an oscilloscope - can display the voltage difference □ Find that inside of neurons have slight negative charge □ Called resting membrane potential (-70mV) - All cells must maintain resting membrane potential to be able to generate electrical signals - Can use electrode to inject current into neuron - cause a shift in membrane potential in neuron □ Using this to make membrane potential closer to 0mV - called depolarisation - Depolarising membrane potential is important step in generating electrical signals that propagate neural networks in the brain

Answer 194

○ Extracellular space is largerly salty water - Salt dissolves into water breaking up into positively charged sodium ions, and negatively charged chloride ions ○ Inside axon, abundance of positively charged potassium ○ Number of structures in cell membrane - Under the right circumstances, these channels will open up and allow ions to move across cell membrane - Because ions are charged, when they move across cell membrane it will cause changes in the resting membrane potential

Answer 195

- When there is enough depolarisation at start of axon, a series of sodium channels open automatically and allow sodium to enter axon - Because sodium has positive charge, sudden increase in positive charge where gates are - Voltage can go to zero and increase - become more positively charged just at that location - After a while, sodium gates close, and there is a reversal in membrane potential at that location in axon -As soon as sodium gates close, new set of gates open up - allow potassium to flow out into extracellular space -Makes inside more negatively charged -If we cross -50mV threshold - automatically open and close sodium and potassium channels ○ In between locations where sodium and potassium are along the axon are the myelin sheaths ○ As the active current moves through one section of myelin sheath, only loses a small amount of current, but still is above the threshold - allowing for a renewal of the active current at the next break in the myelin sheath all the way down the axon - Ensures electrical signal propagates all the way down the length of the axon □ Called Saltatory conduction of AP

Answer 196

○ No matter how much current is injected, so long as it crosses the threshold, the AP amplitude will remain the same

Answer 197

○ Neurons can produce AP without stimulus ○ When stimulus is applied there is a surge of Aps produced - The size of the surge (ie the amount of Aps produced is proportional to the strength of the stimulus) ○ The importance of the signal coming down na axon is communicated by the number of AP rather than the amplitude

Answer 198

• Begins with visual problems, numbness, weakness of the limbs • Ultimately leads to paraplegia, slurred speech, problems with vision and eye movements • Frequent attacks followed by quiescence or remission • Autoimmune disorder that affects the insulation covering nerve cells (myelin sheath) ○ Means action potentials can't be carried down the whole way of the neuron • Effects of myelin damage in MS ○ AP is generated with normal amplitude, but signal begins to leak out of axon as it travels down demyelinated axon - No longer enough depolarisation at next Node of Ranvier to renew the AP

Answer 199

• Presynaptic neuron ○ Axon associated with neuron sending out message • Postsynaptic neuron ○ Neuron receiving message on dendrites

Answer 200

``` • Presynaptic membrane ○ Membrane surrounding presynaptic neuron (lipid layer) • Postsynaptic membrane ○ Membrane on postsynaptic neuron ```

Answer 201

○ Shape of dendrite which conforms to the axon terminal ○ Ensures physical separation between pre and post synaptic neurons is very small - Because AP releases a chemical which has to travel across gap - if gap was large that would take a long time

Answer 202

○ Contain chemical neurotransmitter

Answer 203

○ Gap between axon and dendrite

Answer 204

○ Used to guide the vesicles down to axon terminal to release zone • Release zone ○ Immediately adjacent to the synaptic neuron membrane

Answer 205

○ Vesicle contains neurotransmitter molecules ○ AP triggers vesicle to move toward cell membrane ○ Followed by fusion of the two membranes (of vesicle and presynaptic membrane) ○ When they fuse, it means the intracellular space of vesicle is one with extracellular space of synpase ○ Allows neurotransmitter molecules to be released into synaptic cleft

Answer 206

○ Ionotropic receptors - structures in cell membrane that have their own binding sites, and are ordinarily closed, but when the right neurotransmitter attaches to the binding site, it opens the channels allowing ions to move across the cell membrane ○ There are sodium, potassium, and chloride ionotropic channels ○ When sodium channels are open - excitatory postsynaptic potential (postsynaptic neuron becomes more positive to more excited) (EPSP) ○ When potassium gates are open, potassium leave the postsynaptic neuron, making it more negative, and causing inhibitory postsynaptic potential (IPSP) ○ When chloride channels are open, chloride moves into postsynaptic neuron, so it makes it more negative, therefore IPSP

Answer 207

○ Depolarise the postsynaptic cell membrane | ○ Increase the likelihood that an AP will be triggered in post synaptic neuron (don't always cause them though)

Answer 208

○ Hyperpolarise the postsynaptic cell membrane ○ Decrease likelihood that an AP will be triggered ○ Combined effect of IPSP and EPSPs is called neutral integration

Answer 209

○ Drugs act upon Central nervous system in different ways ○ Most drugs that affect behaviour do so by acting on synapses ○ Two categories of drugs affecting synaptic transmission - Agonists □ Facilitate activity of postsynaptic neurons - Antagonists □ Inhibit activity of postsynaptic neurons

Answer 210

○ Can increase the synthesis of neurotransmitter molecules - Increase likelihood that vesicles have large amount of neurotransmitter so that when they fuse, we get an increased amount of neurotransmitter to influence postsynaptic neuron - Eg L-dopa for parkinsons disease ○ Can increase the release of the neurotransmitter molecules from terminal buttons - Making larger numbers of neurotransmitter fuse with membrane of postsynaptic membrane ○ Can bind to postsynaptic receptors and directly activate them or increase the effects of neurotransmitter molecules - Eg nicotine, which stimulates acetylcholine rceeptors

Answer 211

○ Can block the synthesis of neurotransmitter molecules - Meaning there is less neurotransmitter in each vesicle - Eg PCPA inhibits synthesis of serotonin ○ Can block the release of neurotransmitter from terminal buttons - Botulinum toxin blocks release of acetylcholine ○ Can bind to postsynaptic receptors (covering them up) and block the effect of neurotransmitter molecules

Answer 212

• Amino acids ○ Glutamate & GABA ○ Particularly associated with excitation and inhibition in nervous system • Monoamines ○ Two categories: - Catechloamines □ Dopamine □ Norepinephrine - Indolamines □ Serotonin ○ Play a role in regulating complex brain function - as well as mood and reward systems • Acetylcholine - Associated with muscle activity

Answer 213

○ Rostral-caudal (from nose to tail of dog) | ○ From back to stomach - dorsal-ventral

Answer 214

Anterior/Toward beak

Answer 215

Posterior/towards tail

Answer 216

Towards back

Answer 217

Toward belly

Answer 218

toward the side

Answer 219

toward midline

Answer 220

opposite side

Answer 221

spinal and cranial nerves Made up of: ○ Sematic system - Connects central system to voluntary muscles ○ Motor system ○ Autonomic system - Connects central system to non-voluntary muscles and glands □ Sympathetic system - Arousing, prepares body for activity, uses energy □ Parasympathetic system - Calming, prepares body for restoration of energy

Answer 222

brain and spinal cord Meninges • Cerebral spinal fluid (CSF)

Answer 223

○ Three-layered sheath surrounding brain and spinal cord - Dura mater (outer-most layer) □ Doesn't conform to folds of brain's surface - Arachnoid mater □ Middle layer □ Fine structures creating space - provides opportunity for cerebral spinal fluid to flow between dura and brain itself □ Not found in the Peripheral nervous system - Pia mater □ Conforming to surface of the brain □ Level closest to brain

Answer 224

○ Only found in central nervous system ○ Clear fluid like blood plasma ○ Purpose is to reduce shock to brain from head movements or other collisions ○ Floating the brain in this fluid reduces effective brain weight from 1.5 to 80g - Reduces chance that brain will bump into skull ○ Produced in each hemisphere in ventricles - Fluid from both ventricles then passes through a number of narrow passages to a third ventricle, and from there through down another narrow passage (cerebral aquaduct) to fourth ventricle - spinal fluid then flows out around brain and spinal cord ○ Choroid plexus - contains cells producing CSF ○ Because it is always being produced, it needs to go somewhere, so it is reabsorbed back into the bloodstream as structures called arachnoid villae

Answer 225

○ Telencephalon | ○ Diencephalon

Answer 226

- Two brain hemispheres form cerebrum - Hemispheres have outerlayer - cortex - Region deep within hemispheres contains basal ganglia and limbic system - Grey matter of brain (darker outer part) contains largely neural cell bodies - White matter - has higher proportion of myelinated axon - the connections between neurons in outer cortex - Purpose of folded brain surface is to jam in the 100 000 000 neurons in the brain - Gyri are the outer parts of folds - Sulci are the inner folds - Central sulcus - the fold the goes from the centre of the brain down to the sides of both hemispheres

Answer 227

- Contains □ Thalamus - Relay station for sensory inputs to cerebral cortex - Divided into several nuclei □ Hypothalamus - Controls automatic nervous system and endocrine system - release of hormones for regulating behaviour - No overlap in function with thalamus - Regulates survival behaviours (fighting, fleeing, feeding, mating)

Answer 228

○ Frontal lobe ○ Parietal lobe ○ Occipital lobe ○ Temporal lobe ○ Functional symmetry in visual areas of occipital lobe, somata sensory areas in parietal lobe and some motor areas in frontal lobe ○ Left hem controls aspects like language - involved in analytic processing of incoming information ○ Right hem - involved in aspects of spatial processing - damage leads to difficulties in constructing objects, or drawings - specialised for synthesis of information forming whole pieces

Answer 229

○ Post central gyrus consists of neurons immediately behind central sulcus - Neurons process signals that originate from receptors in our skin ○ Somatasensory neurons project back from spinal cord, travel through thalamus, neurons there project to the primary areas of the cortex responsible for processing incoming somatosensory signals ○ Ordered organisation of the cells along somatosensory cortex ○ Amount of cortex used to process signals coming from different parts of the body does not represent their physical size ○ Somatotopic map - Maps different parts of the body onto cortical surface and tells us something about the functional organisation in this part of brain ○ Body parts with especially large representations in primary somatosensory cortex - Face - cheeks, lips, tongue, vocal musculature - Hands - thumb, fingers, palm

Answer 230

○ Cells in this part of the brain are where signals arrive once they've originated from the eyes and gone through thalamus ○ Arranged according to functional property of importance - Important aspect of vision is where objects are in space - Visuotopic organisation

Answer 231

○ On posterior part of superior temporal gyrus ○ Cells that receive signals originating from ear ○ Cells are organised according to the sound frequency - higher frequencies towards posterior of primary auditory cortex ○ Neurons immediately close together typically respond to signals with same frequency ○ Tells us that auditory processing is understanding sound frequency - Important for recognising certain types of sounds

Answer 232

○ Cells take signals from PAC and process them in a way that gives us a more complex sense of the sound ○ Adjacent to this area is the area that when damaged causes Wernicke's aphasia - Part of brain that takes signals orignating from PAC and allows us to recognise and understand speech

Answer 233

○ Human frontal cortex different from other animals - Relatively larger than non-primates - Higher level of connectivity with the rest of the brain (compared with other apes) ○ Functions - Voluntary, controlled behaviour - Language - Abstract reasoning and planning - Impulse control and emotional regulation - Social cognition - Personality

Answer 234

-part of primary motor cortex - Area of myelinated axons linking the two hemispheres above the ventricles - Role is pure two connect cerebral hemipheres - Three connection types □ Homotopic - Neurons in one hemisphere are connected to the exact same physical location on the other hemisphere □ Heterotopic - Connections where neurons in one hemisphere are connected to neurons in a different place in the other hemisphere □ Ipsilateral - Connections within one hemisphere - Removal of corpus callosum □ Callosotomy - Severs connection between two hems - Can have decision making in one hem without being reconciled with the other - Someone with callosotomy might be asked to choose an item of clothing, and because left side of brain is responsible for understanding language and control right side of body, if you ask them to use their right hand to reach for something, they might say that they are reaching for something - If you ask them to use the left hiand, the right side of brain does not process language, so they might say their reaching for blue dress but reach for red shirt - Usually used to stop epileptic seizures

Answer 235

``` § Mamillary body § Amygdala § Hippocampus § Cingulate gyrus § Fornix ```

Answer 236

○ Important for involuntary movement ○ Within two hems - regions with lower amount of myellinated axons (aggrigation of cell bodies) - Caudate nucleus - Putamen - Globus Pallidus ○ Play important role in regulating non-voluntary movement

Answer 237

○ Divided into - Tectum □ Superior - Process aspects of visual and auditory information □ inferior colliculi - Important for processing auditory information especially in terms of location of the auditory signals - Tegmentum □ Reticular formation - Important for regulating arousal - damage usually causes coma □ Substantia nigra - Produce dopamine - Damage results in lower levels of dopamine

Answer 238

○ Metencephalon - Consists of Pons and cerebellum - Important for regulating aspects of sleep and arousal - Also important for relaying info to and from cerebellum via cerebellar peduncles ○ Medulla (myelencephalon) - Consists of neurons that are important for autonomic function, such as respiration, and links hind brain to spinal cord

Answer 239

○ Highly folded surface - Purpose is to be able to jam more neurons into small space - Has more neurons than cerebral cortex ○ Appears to be particularly important for learning skilled movement - When we learn complex movements and are able to do them quite fluidly, the cerebellum takes over the processing of those movements ○ Also makes changes in motor system in response to unexpected events - liquid in ear detects sudden change in body position, which then sends signal to cerebellum which can use info to cause movements in body to compensate for postural change - without we would fall a lot

Answer 240

``` ○ Vertebrae - Cervical (neck) - Thoracic (chest) - Lumbar (lower back) - Sacral (pelvic region) ○ Spinal foramen - central region consistent across all vertibrae - Channel in which spinal cord resides ```

Answer 241

○ Grey matter surrounded by white matter ○ Surrounded by 3 meninges ○ 31 pairs of spinal nerves (to receive and convey information)

Answer 242

• Regulates smooth muscle (skin, blood vessels, walls and sphincters of internal organs), cardiac muscle and glands) • Controls blood pressure, temperature, digestion and sexual functioning • Two antagonistic systems ○ Sympathetic division - Responsible for arousing us to perform some sort of action ○ Parasympathetic division - Calm down from performing action ○ Both systems are responsible for activity in the same organs ○ However, the fibres controlling parasympathetic activity sometimes follow a very different anatomical route to that of the sympathetic branch

Answer 243

``` ○ Dilated pupils ○ Sweating ○ Accelerated heart rate ○ Increase in breathing rate ○ Decrease in digestive function ○ Secretion of adrenaline ○ Then need to restore body to previous calm state - Separate set of neural pathways that □ Constrict pupil □ Increase salivation □ Slow heart rate □ Constrict brochi □ Upregulate stomach and digestive processes ```

Answer 244

○ Primary sense in the dark | ○ Basis for language

Answer 245

-Nervous system ○ Volume = change in amplitude ○ Pitch = change in frequency ○ Complexity = multiple wave forms with different amplitudes and different frequencies

Answer 246

• Changes in air pressure associated with sound wave - come down auditory canal ○ Cause ear drum/tempanic membrane to oscillate • Ear drum is connected to series of bones called ossicles ○ Malleus/hammer, incus/anvil, and stapes/stirrup - names of ossicles ○ Movement of eardrums causes leveraging movement in the ossicles • Stapes pushes up against cohlea ○ Cochlea - name from looking like a snail ○ It is hollow, and largey rigid except for two places: - Oval window - soft membrane - Round window ○ When stapes moves backwards and forwards against the oval window, causes fluid to move backwards and forwards along cochlea - Fluid moves backwards and forwards because round window can buldge out and in in response to the movement

Answer 247

• Cochlea converts mechanical movement of ossicles into fluid movement along Basilar membrane ○ Basilar membrane runs length of cochlea

Answer 248

○ Converts fluid movements into neural signals ○ Basilar membrane is at bottom ○ Movement of fluid through cochlea either causes hair cells to rub against tectorial membrane, or causes them to flex and bend in that movement of fluid ○ Inner hair cells connects with multiple spiral ganglion cells - Spiral ganglion cells send out action potentials, and bundled together comprise the auditory nerve - send information back to the brain - Damage to inner hair cells largely responsible for hearing loss ○ Multiple outer hair cells make contacts with a single spiral ganglion cell - If outer hair cells are sufficiently excited, the will cause receptor potential which will depolarise the spiral ganglion cells - Once spiral ganglion cells have been sufficiently depolarised, generate action potentials which propagate down the myelinated axons comprising auditory nerve

Answer 249

○ High frequency tone causes more vibration closer to the base of the Basilar membrane ○ Low frequency causes more vibration closer to the apex ○ Hair cells at each location will cause receptor potentials that are directly related to the frequency of the incoming tone - Action potentials generated by spiral ganglion cells associated with different position along the Basilar membrane give information about the frequency being encoded along the Basilar membrane

Answer 250

○ Auditory nerve project to several nuclei in the medulla - at bottom of brain ○ From there, project to contralateral inferior colliculus ○ Then project to both hemispheres through Thalamus ○ Auditory signal originating on one side of body is processed on both sides of brain - Stronger level of processing on opposite side

Answer 251

○ Designed for people experiencing hearing loss due to a loss in hair cells ○ Bypass a functional hair cell stage ○ Electrically stimulate spiral ganglion cells ○ Implant an electrode array along the cochlear ○ Process sound and break it up into different frequencies ○ Match the voltage to the electrode location that induces action potentials in spiral ganglion cells that mimic the sound ○ How do they sound? - Voice recognition requires relatively few electrodes - Music appreciation requires many more electrodes □ Difficult to understand and hear with early cochlear implants - not complex enough

Answer 252

• Electromagnetic spectrum ○ 400-700nm stimulates our photoreceptors and starts process of ability to see • Conversion of that signal happens in eyes • There is a close relationship between position of image on retina and its physical position in the outside world • Retinal neurons that are stimulated by light from the same location in space are bundled together

Answer 253

○ Retinal ganglion cells ○ Myelinated axons of these cells bundle together and go down optic nerve back to the brain ○ Ganglion cells inherit the property of where they originate

Answer 254

- Cones | - Rods

Answer 255

□ cone shape □ Convert light energy into a signal □ The signal passes through to ganglion cells □ Myelinated axons of these cells go back via optic nerve to brain □ Signals coming out of eye are largely the action potentials in ganglion cells □ Three cone types receptive to different wavelengths - determining what hues you see - S-cone (receptive to short wavelengths) - M-cone (peak-sensitivity of 500nm: light that appears green) - L-cone (long-wavelength sensitive cones: appears red) - Signals in cones don't represent colours - they are information about wavelength - not until signals get to brain that it translates to colour

Answer 256

□ Rod shape | □ Receptive to very low levels of light - wha we use in dark conditions

Answer 257

- Photoreceptors do not directly connect with ganglion cells □ Connect to bipolar cells which connect to Ganglion cell □ Other cell types with modulatory role: - At junction between bipolar cells and photoreceptors: horizontal cells - At junction between bipolar cells and ganglion cells: amacrine cells - Cells play a role in processing visual info before it's sent to the brain

Answer 258

○ Objects from right visual field - Left eye: light passes through cornea and lens and projects onto temporal retina □ Axons from retinal ganglion cells project out through optic nerve, down to the left LGN (lateral geniculate nucleus - specialised nucleus of the thalamus for processing visual information) - Right eye: light goes through cornea and lens and projects onto nasal retina (closest to nose) □ Signal goes down optic nerve and cross over at the optic cavern □ Also project to left LGN - Objects in right visual field are processed in left thalamus □ From there neurons project to the left primary visual cortex

Answer 259

puts together receptive fields in a way that enables us to recognise common objects

Answer 260

distinction of 'where and what'

Answer 261

○ Can occur because of bloackage to a particular artery that supplies blood to that part of the brain ○ If cells die, we have a loss of visual perception that is related to the visuotopic arrangement of V1 ○ People with right visual field loss - would see thing son the left side, not the right -Damage does not always cause a loss in sight

Answer 262

□ Damage to V4 - results in loss of colour in right visual field

Answer 263

-Motion blindness □ Damage to MT (important for perception of motion) □ Rather than seeing smooth motion, you see series of still images that change in position

Answer 264

□ Temporal lobe damage □ Difficulties recognising familiar objects □ It isn't that they don't know what the object is - if you show them the actual thing they will know, it's just they can't translate the visual representation of something into an object they know

Answer 265

○ Face inversion effect: - Normally see upright faces - Parts of neuron that see a face are particularly tuned to seeing faces in that orientation ○ Face blindness (prosopagnosia) - Lesion to right fusiform gyrus - particularly active when looking at faces - Able to recognise other objects

Answer 266

``` ○ Behavioural ○ Autonomic - physiological responses in body prepare for fight/flight response ○ Hormonal - Reinforce physiological changes ```

Answer 267

○ Bard - used ablation to study effects of removal of different brain parts removed from cats' on their agression ○ Observed 'sham rage' in cats whose cerebral hemispheres had been surgically removed - Sham rage = overt aggressive responses to stimuli that wouldn't display the same agression ○ Sham rage was absent when hypothalamus was removed ○ Posed that hypothalamus was responsible for generating aggressive responses, but cerebral hemispheres play a key role in controlling the emotional expression

Answer 268

○ Consists of amygdala, hippocampus, fornix, medial surface of both hemispheres - Proposed by Papez and McLean to be important in emotional processing

Answer 269

○ Used bilateral ablation to temporal lobes in monkeys ○ Caused impaired visual recognition (psychic blindness) ○ Also develop hyperphagia (oral exploration of objects) ○ Displayed impulsive and stereotyped actions, aberrant sexual behaviour ○ Developed absence of fear

Answer 270

○ Comprised of large number of subnuclei ○ At the top - information coming in from thalamus and cortex into lateral nucleus ○ From there, there are connections that ultimately stimulate central nucleus ○ Central nucleus - particularly important - Outputs to the hypothalamus (important for regulating autonomic arousal) - Ideally suited to cause physiological changes which are important component of emotional processing - Lesions abolish fear response - Stimulation is sufficient to cause fear and agitation

Answer 271

• Demonstrated importance of frontal lobes in certain types of emotional response • Tamping iron went through skull and all the way through his head - landed behind him • Remarkable things about case: ○ He survived injury and infection afterwards ○ Survived long enough for behavioural changes to be observed ○ No longer the person he was before - changes in emotional responses • Iron broke his cheekbone - important because it allowed the left side of the skull to lever slightly off ○ Normally if something penetrates skull, there is an increase pressure on the brain having detrimental effects on the entire brain ○ In this case, brain injury was likely to be restricted to the part of the brain penetrated by iron, not spread throughout the brain ○ Missed optic nerve and all the parts of brain regulating arousal and consciousness - Would have died instantly if they were damaged

Answer 272

``` ○ Personality changes profoundly - Fitful, irreverant, profane □ Swore a lot - Impatient, obstinate, capricious □ Unable to settle on a plan or follow a course of action - Unable to plan for future - Not employable in old job ○ Had to have jobs where he didn't make decisions ○ Died from seizures due to brain damage ```

Answer 273

* Involved in social and emotional decision making * Processes, evaluates and filters emotional and social information * Damage impairs decisions that rely on feedback from social and emotional cues * Evidence that people who have higher levels of antisocial behaviour have reduced levels of grey matter in this area too

Answer 274

○ Threat leads to behavioural and physiological responses ○ Leads to pounding of heart and running away ○ Somatosensory signals are then interpreted as emotion

Answer 275

○ Said that people have cogitive appreciation of their motion, so James-Lange theory doesn't seem right ○ Emotion-inducing stimulus, and there are automatic behavioural and physiological changes ○ Importantly, suggested that we can appreciate the emotional aspect of the stimulus without the physiological changes

Answer 276

○ Importance of somatosensory feedback from body - James-Lange theory: people who don't have somatosensory feedback (spinal injury) - would expect them to have no emotion in response to emotion-inducing stimuli - Cannon-Bard theory: we don't need physiological changes to experience the emotion ○ People with spinal lesions - do have emotional response (supporting Cannon-Bard theory) -But their emotional response is diminished (suggesting neither theory is actually correct)

Answer 277

○ Schachter and Singer's two-factor theory of emotion - Physical arousal plays a primary role in emotion - But arousal is the same for a wide variety of emotions ○ We must identify the arousal to feel the emotion - Depends on context and memories of previous experience - Feelings are an interaction between physical arousal and the cognitive label given to that arousal - Eg - being on a rollercoaster can have same arousal as seeing a bear

Answer 278

* Decision making guided by an evaluation of the consequences of our actions * Faced with the same decision activates memories of past events * These representations activate traces of the bodily responses to previous behaviour * Feelings steer us towards decisions that increase positive feelings and decrease negative feelings * Allows us to anticipate the emotional consequences of our actions

Answer 279

○ Patients with frontal lobe damage compared emotional responses with those who didn't have frontal lobe damage ○ Found images that people usually have strong emotional response to and had previously been shown induce a change in skin conductance due to sweat ○ Showed images to both groups of patients and some neutral to compare their emotional responses ○ Found that when an emotional image was shown, the control group had an increase in skin conductance ○ Frontal-lobe impaired patients showed no change in skin conductance across the whole series of photos - Not getting trace physiological response, and presumably can't use that to help guide behaviour

Answer 280

○ Two decks of cards: pile A and B ○ Both piles are similar in that they have cards with a monetary value, and either a 'win' or a 'loss' ○ Pile A has larger money values on each card compared with pile B ○ If you choose from pile B, in the long run you'll win money, if you choose from pile A you will loose money ○ Control subject - Contemplating choosing from pile A - leads to physiological respons that makes them think they should choose from pile B ○ Frontal-lobe impaired people - Continue to be lured by large amounts of money in pile A and will continue to choose from it, despite loosing money - Do have emotional response to loss, but they will continue to choose from pile A despite this

Answer 281

• Blue square would appear on screen immediately followed by electric shock • In normal patients, after fear conditioning, there will be an increase in skin conductance after seeing the blue square • Patient with amygdala damage, only have a change of skin conductance after electric shock, not the square ○ Doesn't mean they don't have capacity to experience the fear, it just means that the fear conditioning was insufficient to cause a physiological response ○ While the blue square was not the CR, patients knew that the blue square signalled an electric shock ○ Despite cognitively knowing, the amygdala was unable to help the patients learn that the blue square was something to be feared

Answer 282

○ Le Doux: two parallel pathways - 'Low road' □ Quick but dirty information to amygdala (thalamus --> amygdala) - 'High road' □ Slow but detailed picture of sensory information (thalamus --> sensory cortex --> amygdala) ○ Fear response starts with something potentially dangerous in world around us - brain needs to get sensory information from eyes and possibly ears - Sensory information comes back via sensory thalamus □ From there - direct link to amygdala □ Because this pathway involves low amount of sensory processing, call it 'dirty' □ Not signal that corresponds to conscious recognition of incoming sensory information □ Example is jumping because you see an object that could be a snake □ Enables you to respond quickly in potentially fatal situations - High road enables cognitive awareness of the situation - could realise it's a stick not a snake so don't need to react □ Takes longer

Answer 283

• Emotional reactions to questions are used to determine 'truthfulness' of answers • Measures physiological responses associated with activity of autonimic ervous system • Still used routinely by law enforcement in many countries • Effectiveness of lie detection can be evaluated by 'mock crime' procedure • Two approaches to questioning: ○ 'Control-question' technique - Establishing a baseline by asking a number of neutral questions and then asking a question which might relate to someone's guilt - 80% detection of liars - False positives ○ 'Guilty-knowledge' technique - Relies on fact that if someone has been involved in a crime, they will have knowledge about the crime scene - Makes them recall the crime - 88% detection of liars - No false positives

Answer 284

* Plays an important role in regulating what we're aware of in the world around us * Involves prioritising processig information for objects of interest at the cost of less awareness of other things around us * Is conscious awareness essential for our ability to orient the world around us?

Answer 285

• V1 (primary visual cortex) - important for conscious visual experience • Artery that supplies blood to visual cortex in both hemispheres ○ Interruption of blood supply will result in neuron death in V1 - Lose conscious visual experience in the part of visual field process by those neurons • Neurons in right hemisphere = process info coming from left visual field ○ Lesion of primary visual cortex in left hemisphere = complete loss of visual consciousness in right visual field ○ Homonymous hemianopia

Answer 286

• Occurs following unilateral damage restricted to the primary visual cortex • Above-chance visual performance in the 'blind hemifield' ○ Patients may say they have no ability to process visual information in that area, but there is evidence that there is some happening • When testing to see the processing, shows preservation of: ○ Pupillary reflexes - Where puils restrict ○ Manual and saccadic localisation - Pointing and looking ○ Wavelength and motion discrimination - Can discriminate against objects that are different colours/moving ○ Orientation and shape discrimination

Answer 287

○ Patient looks directly ahead ○ Lights can be turned on in right, left, upper, lower visual fields ○ Two tones are played, with one of them a lights is turned on - patient is asked if it was turned on during first or second tone ○ If light was turned on in blind region, they would believe they were guessing - If that were the case they woul get 50% right - But they had correct responses 90+% of the time in the blind region - In one particular area (outside of blind region) - much lower results □ Performed by chance □ When light is being presented in optic disk - Part of the retina where the myelinated ganglion cells exit eye - don't have any photoreceptors there, so person should be performing at chance

Answer 288

○ Lights presented in left and right, and patients would have to point at where it is ○ When patients do it in their blind region, they don't think they can - But their performance was not much worse than in their intact visual field, despite the fact that they thought they were guessing

Answer 289

○ Some fibres to go from the LGN (in the thalamus) back to the primary visual cortex - Project to the Superior colliculus □ Evolutionary older sensory processing pathway □ presumable these areas play a role in helping animals orient to the world around them without conscious experience □ May explain how information can be processed in vestidual information that are still intact - From there to the Pulvinar

Answer 290

``` ○ Selectivity § Spatial § Temporal § Motoric ○ Capacity limitation ○ Vigilance ('sustained attention') ○ Perceptual set ('expectation') ○ Switching ```

Answer 291

○ Screen with letters on it ○ Central fixation point ○ Device with a switch that would provide a very brief light spark ○ Helmholtz would look at middle of screen but shift his attention covertly to another location ○ Couldn't report letters of where he was looking, but had enhanced processing of letter where he had been attending covertly ○ Can concentrate attention on a particular part of our peripheral nervous system, while excluding attention from all other parts - Limited resources - need to priorise some visual input, so need to take resources from other locations

Answer 292

• Spatial attention alters neural processing speed ○ Central focal point ○ A target ○ Before target appeared, a cue was presented indicating the side the target would be on - Valid trials - cue was right - Invalid trial - cue was wrong - Neutral trial - indicated both sides ○ 80% of trials were valid ○ Did shifting attention away from or towards target have an impact on how quickly you processed the target? - Response times were faster on valid trials than neutral trials □ Enhanced processing of info at location we are attending to - Invalid condition - much slower response times □ Slower neural processing times at locations that we are not attending to

Answer 293

• Neurons in parietal cortex are modulated by attention ○ Monkeys were trained to maintain fixation at a certain location ○ Target can appear to the left or right ○ Monkey keeps looking at fixation point, but we can look at the action potentials generated when light stimulus is flashed on in the receptive field for that neuron ○ If there is no reason for the monkey to shift its attention there, presume its attention would be used to maintain fixations ○ How do we get monkey to covertly shift attention from where it's looking to the location of the receptive fields? - Got monkeys to shift attention away from where they were looking by dimming the light very subtly - Monekys could only get juice reward if attention had shifted to that location - When light dimmed they would press a lever and get a reward - If they didn't notice, they wouldn't press the lever - High motivation - Much larger number of action potentials very soon after light is turned on □ Could reflect speed of processing

Answer 294

○ Causes unilateral spatial neglect ○ Occurs after damage to one side of brain (usually in right hem) ○ Patients behave as if the affected side of space has ceased to exist - Ignore food on one side of plate - Fail to shave one side of face - Bump into objects on one side - Fail to read text from one side of the page

Answer 295

○ Line by section task - Need to draw a vertical line bisecting the horizontal line in half - Patients draw that line significantly to the right of the horizontal line - not in centre - as though left hand side doesn't exist ○ When asked to draw house or tree - Aspects missing from left hand side - Position of features on left hand side of objects seems to be disarrayed □ As though the parietal lobe is necessary to work out where things have to go together to make the whole form

Answer 296

○ Medial frontal gyrus ○ Inferior frontal gyrus ○ Superior temporal gyrus ○ Inferior parietal lobule

Answer 297

○ When presented images of two houses, one of which had a fire on the left hand side - patient asked if houses were the same or different - Patient said they were the same ○ If fire was on the right-hand side (and they had left unilateral spatial neglect) they would say they were different ○ When asked 'which house would you prefer to live?' - If fire was on the right - would say the house without fire - When fire was on left side - would expect them to have no awareness of fire □ Still routinely choose house without fire □ Have no insight into why they would make that choice