Cognative Flashcards
know everything
Cognition definition
Set of all mental processes that allow us to aquire knowledge/understanding through though, experience and the senses
Criticisms of the view that humans are stimulus response machines
Does not allow for parallel processing
Ignores top down processing
Top down processing
Stimulated by the individuals prior knowledge etc
Bottom up processing
Stimulated by external stimuli
Evidence that neurons represent specific information
Found a certain set of neurons fire when Luke Skywalker is mentioned (similar ones firing when other star wars things mentioned)
Rate coding
A greater rate of neuronal response is used to represent information
Temporal coding
A greater synchrony of neuronal responses is used to represent information
Possible types of coding (2) and which is more likely
Rate and temporal coding, temporal being more likely based of evidence
Different approaches to studying cognition (3)
Experimental Cognitive Psychology
Cognitive neuropsychology
Cognitive neuroscience
What is experimental cognitive psychology
Studying behaviour in lab setting (with manipulations), traditionally focusing on behavioural measures
Limitations of experimental cognitive psychology
Ecological validity (real-world translation)
Only indirectly measures cognition
Relies heavily on theory
What is Cognitive neuropsychology
Studying cognition in brain damaged patients to find specific brain areas role in cognitive functions
Limitations of cognitive neuropsychology (4)
Rare to get pre-damage measures for patients on performance
Often has complex damage in several regions
All brain damage is unique
the brain is unlikely to be modular
What is cognitive neuroscience
Relates brain structures and function to cognitive processes, usually by recording brain activity while tasks are completed
Tools in cognitive neuroscience (4) and their use
EEG for electrophysiology imaging
MRI for structural imaging
fMRI for functional imaging
TMS and TCS for brain stimulation
Single cell recordings
Very small electrode recordings from within an axon, or outside an axon membrane
When are single cell recordings used
Usually just on animals but known to be used on epileptics
EEG
Via electrodes in the scalp, it records the electrical activity of a large number of neurons firing together
Event related potential (ERP)
Average waveform from a task recorded multiple times, used to compare between conditions
Advantages (3) and disadvantages (2) of EEG
Adv: good temporal resolution, portable, cheap
Disadv: Spatial resolution, only measures brain’s surface
How MRI machines work
Very strong magnetic field (0.5-0.7 Tesla’s) on scanned area with single protons aligning to it. Alignment disturbed by short radio frequency pulse and the change is measured - different tissues realign at different times, giving brain map
Diffusion Tensor Imaging (DTI)
For structural imaging, it measures white matter (axons) by measuring the direction of water diffusion
How fMRI works
Doesn’t measure neural activity, it measures BOLD signals - oxygenated blood has higher signal than deoxygenated as it has less magnetic field disturbance
What does BOLD stand for
Blood Oxygenation Level Dependent signals
Hemo-dynamic Response Function (HRF)
The way blood changes to a stimulus
??
Advantage and disadvantages (2) of fMRI
Adv: spatial resolution
Disadv: temporal resolution, doesn’t directly measure neurons (inference required)
How TMS works and what it stands for
Uses short magnetic pulses that transiently affect electrical activity in a localised patch of tissue under the coil
Transcranial Magnetic Stimulation
How tDCS works and what it stands for
Uses small current flowing constantly from one electrode to another. Area under cathode is inhibited and under anode is excited
??
transcranial direct current stimulation
How tACS works and what it stands for
Uses small current alternating in flow from one electrode to another, inducing oscillations at different frequencies
??
transcranial alternating current stimulation
Advantages (2) and disadvantages (2) of tDCS / tACS
Adv: provides causal evidence, is mostly non-invasive
Disadv: stimulation is weak making weak effects, risky for epileptics
Summary of process of vision from eye to cortex (3)
Reception - absorbed by photons
Transduction - converted into electrochemical pattern in neurons
Coding - represented in the brain
Two types of retina and their function
Cones - process colour and sharpness of vision
Rods - process movement and dim light
How many 1) cones and 2) retina are there in the eye and where are each located
1) 6 million, mostly in the fovea
2) 125 million, in the outer regions of the retina (peripheral vision)
Trichromatic theory for eyes
As all colours mix into three primary colours, it was proposed the eye has three colour receptors responding at different wavelengths (found to be true)
Three colour receptors / cones in eye
Short wave length detects blue
Medium detects green (and yellow)
Long detects red
Problem with Trichromatic theory
Doesn’t account for the negative after image - e.g. staring at green square for a while makes a red afterimage for a second (opponent process) on white background after it disappears
Opponent process theory for eyes
Colour perception has 3 opponent processes: red/green, blue/yellow, light/dark. Combined in an opponent way
Duel process theory for eyes
Links opponent processes to the combinations of inputs from 3 cone types (trichromatic theory)
Support for opponent process theory for eyes
Opponent cells found in monkeys geniculate nucleus
Colour constancy
Tendency for a surface to appear the same colour despite a dramatic change in light source (brain makes sense of it - in concert with coloured lights, everyone still same colour) - proves perception is constructive
Parvocellular pathway
Sensitive to colour and fine detail, input comes mostly from cones
Magnocellular pathway
Mostly motion sensitive, inputs come from rods
Visual perception pathway summary from eye to brain
Retina to optic nerve to optic chiasm to Lateral Geniculate Nucleus to cortical area
Why your right visual field is processed by the left side and vice-versa
Signals cross from right visual field to the left side of the retinas, and come through in straight lines to left side of brain
Receptive fields
The region of sensory space in which light will cause neurons to fire
Retinotopy
Things spatially near to each other are processed by cells near to each other
Lateral inhibition
A reduction in activity of a neuron caused by a neighbouring neuron
Lateral Geniculate Nucleus (LGN)
Part of the thalamus, it is a subcortical relay for most sensory inputs and motor outputs, correlates incoming signals from the retina in space and time
Primary visual cortex (V1)
Extracts basic information (edges, orientations etc) from the visual scene and then some more complex information (colours, movement, shape etc)
Blindsight
Caused by damage to V1, patient cannot consciously report objects in space but can make some automatic visual discriminations through other visual pathways
Visual pathway to V1 (primary visual cortex) is called…
Genial ostriate route (thought to be fore conscious vision)
Central cullcus
Visual motor system (automatic)
‘Where’ pathway
After V1, goes through pariental processing pathway concerned with movement processing (‘vision for action’)
‘What’ pathway
After V1, goes through temporal processing pathway concerned with colour and form processing (vision for perception) - goes through lateral occipital and temporal lobe
Patient with lateral occipital cortex damage would lose function in….
Their ‘what’ pathway, difficulty locating and identifying objects (but can automatically interact with them)
Functional specialisation theory for vision
Different parts of visual cortex specialised for different visual functions
Function of V1 to V5 according to functional specialisation theory for vision
V1 - lines V2 - similar to 1 V3 - responds to form V4 - for colour V5 - for movement
Cortical achromatopsia
Damage to V4, a patient cannot see colours (often V2 and V3 damage also) but has fully functioning retina. However implicit colour perception intact as can still see through expectations from experience before damage
Akinetopsia
Damage to V5, deficit in movement visual processing with everything else intact
Challenge for functional specialisation theory for vision
How are V1 to V5 bound together to make sense, colour and shape are not seen separately
Visual perception synchronisation hypothesis
A potential solution to the challenge for functional specialisation, the functions (V1-V5) are synchronised (temporally coded) to bind together - likely attention dependent
Model for object recognition in steps
Early visual processing (colour, motion, edges etc)
Perception segregation (grouping visual elements)
Map this onto representation (expectations) in brain
Attach meaning to object (‘what’ stream)
Perceptual segregation
Separate visual inputs into individual objects
Gestalt Psychology
studying perceptual segregation
Law of Pragnanz
Of several possible geometric organisations, the one with the simplest, stablest shape will occur (assuming segregation early in processing)
Gestalts laws of perceptual organisation (4), how inputs are organised
Law of proximity (how close they are)
Law of similarity
Law of continuation (whether it carries on)
Law of closure (whether it is half blocked from sight)
Criticisms of Gestalts laws of perceptual organisation (3)
Mostly descriptive findings
Evidence relies heavily on introspection and 2D image examples
Does not include top-down processing’s effect on segmentation
Where V1 to V5 are located
The occipital lobe
Agnosia
Impairment of object recognition with no primary visual deficits
Types of agnosia (2)
Apperceptive and Associative
Apperceptive agnosia
Impaired process of constructing a perceptual representation (can see the parts, not the whole), associated with damage to lateral occipital lobes
Associative agnosia
Impaired process of understanding the function of objects (can see the whole but not the parts, impaired mapping of perception onto stored knowledge), associated with damage to left occpito-temporal lobe
Damage to bilateral ventral-medial occipital lobe causes…
Apperceptive agnosia, patient will perceive objects by parts (see a handle and brush, not a paintbrush).
Prosopagnosia
Patient that’s unable to recognise faces, caused by damage to Fusiform Face area (FFA) - part of the ventral stream
Debate of function of Fusiform Face Area (FFA)
Many believe its specialised to recognise faces, but some think its for expert processing of things constantly seen. However patients with prosopagnosia still have expert processing of other things
Uniqueness of faces for visual processing
Configurally / holistically processed (making prosopagnosia an apperceptive agnosia)
Horizontal information very important for recognition, also cannot be recognised up-side-down
Attention
The taking possession of something in vivid form by the mind
Why is attention necessary
It makes sense of the world, 108 bits per second travel through the optic nerve (much more than the brain can process), so attention needed to focus on necessary things to process
Experiments demonstrating attentions limits
Change blindness (Skoda advert) Attention blink Inattentional blindness (gorilla study)
Summary of inattentional blindness study
Told to watch video of two teams bouncing and passing a ball between themselves and count the passes. Because their attention was drawn, a large proportion did not notice a dancing gorilla coming on screen
(the more difficult the task set, the less they saw the gorilla)
Cocktail Party problem
How do humans focus in on one conversation/noise so well in a loud area with lots of other noises, yet also process other noises at a lower level and can attend to them if relevant to (e.g. hearing your name)
Very difficult to program computers to do this
When a voice is easier to attend to in a loud, cocktail party problem room (2)
Familiar voices (top down processing) Depends on features (high pitch easier than low)
Broadbent’s theory of sensory processing
Parallel inputs go to sensory register where they are filtered based on salience of physical characteristics. Inputs that pass the sensory register (bottleneck) go onto later, more complex processing
Problems with Broadbent’s theory of sensory processing (2)
Does not account for top-down processing’s influence on the sensory register
As seen in blindsight patients, stimuli that aren’t consciously registers still alter behaviour so must be processed further than Broadbent was proposing
Deutsch and Deutsch’s late selection theory of sensory processing
All stimuli is fully unconsciously analysed, with the most relevant passing the sensory register and coming to consciousness, effecting response more
Problem with Deutsch and Deutsch’s late selection theory of sensory processing
Imaging shows ERP’s to be smaller if it remains unconscious later on, indicating an earlier sensory register than they proposed
Treisman’s leaky filter, flexible theory of sensory processing
Unattended information is filtered after the sensory register, going through a hierarchy which takes physical characteristics and personal meaning into account. When limited capacity reached, hierarchy tests are precluded for all but the attended stimulus
Cognitive load
Phenomena that some simple tasks are completed simultaneously much worse than some complex ones - indicates processing semantic information is prioritised over physical characteristics
Endogenous attention
Internal choices that makes one react faster to stimuli in a peripheral part of space
Exogenous attention
External queues that make one react faster to stimuli in a peripheral part of space, only when the stimuli comes quickly after the queue
Posner’s attention systems (2)
Endogenous system (top-down) - controlled by intentions, expectations etc (depends on person!) Exogenous system (bottom-up) - automatically shifting attention from uninformative peripheral queues
Evidence for object based attention (not space)
Participants shown translucent, hybrid images of house and face and sometimes one moved. Brain area for each object was activated more when attending to that one, and even more so when object moved
Central capacity theory
A central executive function is flexibly used to direct attention (has limited resources)
What are dual task costs and why do they appear
Appear due to limited resources of attention, they are when two or more tasks are performed badly when done simultaneously
Multi-tasking / divided attention’s location in the brain
Imaging shows it to be in the DLPFC
TMS studies show impaired divided attention when DLPFC is impaired - appears to distribute resources
Question surrounding visual search
How does the brain search for all the features of the object it is tasked for all at once and so well?
Feature integration theory of visual search (FIT) and implications
Features of an object are encoded in parallel, prior to attention. Making them separable from the object itself when visually searching
Meaning if an object has a unique feature, it can be detected without attention. If not unique, attention/visual search is needed
Stages of visual search according to Feature integration theory of visual search (FIT)
1) Rapid initial parallel process to identify features (no attention)
2) Slower, serial process of spatial attention to form objects from the features (give meaning) - top down influence
Evidence for Feature integration theory of visual search (FIT) (2)
Search time for items with a unique feature is not effected by the number of distractors
Illusory conjunctions
Illusory conjunctions
Showing two objects briefly in periphery means they often experience a combination of the two object’s features - often highly confident of experience, not just guessing
When do Illusory conjunctions occur (5)
Focused attention is absent Relevant stored knowledge is absent Spatial attention absent In peripheral vision Not temporally, just spatially (exact same time)
Evidence against Feature integration theory of visual search (FIT)
Negative priming tasks show unattended stimuli are semantically processed (processed early - stage 1?)
Neglect patients have problems with both conjunctive and single feature visual search targets, indicating they are not in separate systems
Guided search theory (dual path model) of visual search
Emphasising top-down processing, it proposes a mix of serial and parallel processing is used. Pre-attention processing gives an activation map of how ‘promising’ each stimuli is (the more promising the more prioritised to pass through the attentional bottleneck)
Balint’s syndrome
Damage to the bilateral occipito-parietal cortex causing simultanagnosia (could not focus on one object at a time, and could not combine features to form objects (constant conjunction errors
Brain damage that causes problems with feature binding of visual objects (2)
Parietal lesions cause spatial binding problems and Thalamus lesions cause binding problems linked to top-down processing
Brain areas that influence feature binding in visual search (conjunction) tasks
Posterior temporal cortex (and parietal cortex) activated in tasks
Intraparietal sulcus reduces illusory conjunctions, indicating its role in conjunction of objects (activation gives higher performance)
Hemispatial neglect cause
Usually from stroke, lesions to a specific portion of the parietal lobe in one hemisphere
Symptoms of hemispatial neglect
Lack of awareness of stimuli presented to contralesional (other side from brain damage) side of space causing: inability to copy, imagine/remember (even pre-injury memories) or attend to objects on that side of space
Extinction attention disorder
Often detect stimuli in ipsilesional side of space (same as brain damage) but not contralesional - showing a bias
Most hemispatial neglect patients also have this
How much processing of contralesional field takes place for hemispatial neglect patients
A lot of basic in the visual cortices but much less than controls by the point of the dorsal parietal lobe
Evidence for hemspatial neglect patients’ attention being one of object deficit rather than space
Often seem to neglect the contralesional side of all objects in the scene, not their contralesional side
Evidence for strong processing of contralesional field in hemispatial neglect patients
Has a strong priming effect (faster reaction time) when an associated object is later presented in the ipsilesional field (must have been processed through ‘what’ stream)
Most common lesion for hemispatial neglect patients and evidence for it
On the right inferior pariental lobe (contralesional side on the left most often)
TMS on area causes temporary neglect symptoms
Is hemispatial neglect an attention or perception disorder
Attention
Evidence for an intact endogenous attention system in neglect patients (2)
They benefit from valid cues (arrow indicating direction of stimuli) when doing covert attention tasks
Patients are most impaired when trying to disengage from their ipsilesional side
??
Is hemispatial neglect more an exogenous or endogenous attention disorder and what are the implications
Exogenous, they can attend much better when asked to deliberately but struggle with automatic attention
Hemispatial neglect without brain lesions
Occurs when very drowsy, attention tends to shift to right side of visual field. Suggesting a left hemisphere attentional dominance for healthy people
Prevalence of ADHD
5-10% of children, 2-5% of adults, ratio of 3:1 boys:girls
Diagnostic subtypes of ADHD and how common they are
ADHD/IA: Predominantly inattentive (30%)
ADHD/HI: Predominantly hyperactive (9%)
ADHD/com: Combined (61%)
Inattention symptoms of ADHD (4)
Poor attention to detail
Difficulty persevering
Inability to follow instructions
Often forgetful
Hyperactivity symptoms of ADHD (3)
Tendency to fidget
Talks excessively, often before thinking
Tendency to interrupt
Requirements for ADHD diagnosis other than symptoms (2)
Present before aged 7 (a developmental disorder)
Impaired in two or more settings (school, home etc)
Risk factors for ADHD (4)
Genetics (4 times more likely if other family diagnosed)
Prenatal alcohol or tobacco exposure
Post natal pre-frontal damage
Premature births or low birthing weight
Neurocognitive deficits of ADHD (4)
3-4% reduced cortical volume (especially PFC)
Reduced cortical connectivity (axons) between hemispheres
Reduced grey matter and axons in fronto-parietal attention networks
hypoactivity (less) in DLPFC (the ‘choosing’ part of attention)
Imbalance in dopamine and noradrenaline circuits
MANY MORE - research xx
Medication for ADHD (2)
Methylphenidate (Ritalin, metadata etc)
Dextroamphetamine (Adderall)
How ADHD medication works (2)
Block reuptake of noradrenaline and dopamine, whilst facilitating their release
Enhance their availability in the PFC (noradrenaline) and Basal Ganglia (dopamine)
Executive function
Controls considered behaviours in a meta-cognitive way over multiple specific domains
Brain area predominantly associated with executive function
The PFC
Characteristics of the (1) lateral and (2) orbital and medial PFC
1) ‘cold’ control processes, cognitive aspects
2) ‘hot’ control processes, social regulation etc
Location of frontal lobe
Everything in front of the central sulcus
Situations to use executive function (5)
Planning / decision making Error correction / trouble-shooting Complex or skill required situations Dangerous situations Overcoming habituation / temptation
Describe ‘tower of London’ executive function task and brain activity
Move blocks into a required order (only one at a time), requiring planning and working memory. DLPFC highly active
Describe Wisconsin card sorting executive function task and brain activity
Sort cards and adapt to changes in rules throughout, requiring trouble-shooting. VLPFC highly active for this
Meaning of Dorsa and Ventra
Dorsa is above, Ventra is below
Describe Stroop executive function task and brain activity
Say the colour of the word, not the word written. Requires the overcoming of habituation. Anterior Cingulate Cortex (ACC) and pre-Supplementary Motor Area (pre-SMA) are highly activated
Anterior Cingulate Cortex location and function
ACC located on medial wall of brain of frontal lobes, generally appears responsible for error detection (not correction) and response conflict
Pre-Supplementary Motor Area (pre-SMA) location
In frontal lobe in motor area
Non-unitary model of working memory
Assumes PFC divided into separate processes: VLPFC responsible for maintenance / retention and DLPFC for manipulation / updating
Posterior cortex location and function
Back of head in cortex, is the storage site of information
Evidence for DLPFC’s manipulation role in working memory
Damage to it impairs patients at self-ordered pointing tasks which require memory updating (supported by PET scan studies)
Role of left DLPFC in working memory according to the hemispheric non-unitary model and evidence (2)
Specialised in selecting a range of plausible responses and free will actions
Activated when choosing a finger to move, TMS shows impairment
Role of right DLPFC in working memory according to the hemispheric non-unitary model and evidence
Specialised in monitory and sustaining attention (info held in mind) for both external and internal information
Activity greatest in uncertain conditions where attention more important (tip-of-the-tongue states)
Describe n-back task and brain activity
Click when an image in sequence is the same as it was n times ago. Right DLPFC highly activated the more difficult it is as conditions of uncertainty
Role of left VLPFC in working memory according to the hemispheric non-unitary model
Retrieval and maintenance of semantic or linguistic information (known as Broca’s area)
Role of right VLPFC in working memory according to the hemispheric non-unitary model
Retrieval and maintenance of visual and spatial information
Anterior prefrontal cortex (APC) function
Multi-tasking, maintaining future intentions whilst performing other tasks
Unitary theory of working memory / executive function and evidence (2)
Just one underlying function controlling all specialised areas
Performance on tasks all correlate with each other (suggesting fluid intelligence)
Single cell recordings in monkeys implies any area could perform any executive function
Goldman-Rakic model for executive function
Assumes a unitary executive control but has some divisions. For example, spatial (dorsal) and object based (ventral) working memory
Evidence against Goldman-Rakic’s model for executive function
Some experiments show involvement in both areas that it claims there is divisions
Multiple demand network model for executive function
MORE UNDERSTANDING NEEDED
Executive function tasks are divided by fronto-parietal brain regions into sets of less complicated tasks (broken down into ‘attentional episodes’
??
Remembering
Retrieval of memory into conscious awareness
Process of retrieving and producing a memory
Encoding then consolidation then retrieval then the memory
Episodic memory
Remembering or recognising from previous experience
Semantic memory
Knowledge recalled unrelated to experience
Memory trace
Mental representation of previous experience
Taxi driver memory study
Found them to have more active hippocampus’ (episodic spatial memory) as they needed to remember so many routes
Differences found in taxi and bus drivers brains (2)
Taxi drivers have more grey matter in their posterior hippocampus (thought for navigation)
Bus drivers have more grey matter in their anterior hippocampus (thought for visio-spatial information
(the areas compete for activation, more in one causing less in other)
Autobiographical memory
From events in ones own life
Why memories can become less accurate every time they are recalled
The next time they are recalled one will be remembering a memory of a memory from the previous recall (they are updated in content)
Schematic processing principle
A memory is the interaction between the event and our own existing schemata
When a memory is schema-congruent…
It can provide retrieval cues and assumptions can be made
When a memory is schema-incongruent…
Unexpected and uniqueness can attract attention
Effects of schema on memory (3)
Determines how information is processed
Determines how memorable information is
Determines how memories are changed / updated
How schemas influence the processing of memories
Make the information coherent but not necessarily accurate, it is made to fit with the information already fitted by the schema in our memories
Explanations for childhood amnesia (lack of memory up to 3 years old) (3)
Freud saw it as repressed sexual feelings towards parents
Maybe due to underdeveloped hippocampus and frontal lobes
Underdeveloped schemas and sense of self (babies feel like they are a part of the mother
Cross cultural differences of childhood amnesia and reason
Average age of 1st memory in the US is 3.8years but 5.4years in China
Could be because of greater focus on the baby as an individual in the US
Reminiscence bump in memory and reasons (3)
Older people remember much more from 15-25 than any other years
Because brain is at neurological peak, they are formative years, things are experienced for the first time a lot (supported by bump for people who emigrated at certain time)
Why autobiographical memories can be inaccurate (3)
Tendency to put oneself at centre of stage
Tendency for favourable views of oneself
Tendency to fit events with ones schema
Example of the effect of schemas
Students were much more willing to say grades were important to them after an exam if they did well, and many changed their answers from before the exam depending on how it went
Flashbulb memories
Highly detailed, vivid memories for surprising events that are resistant to forgetting
Research showing the accuracy of flashbulb memories
Though they feel vivid, research shows they had the same detail as normal memories from the same time only felt with more emotion
Facts showing inaccuracy of witness testimony in court (3)
48% wrongful convictions due to misidentification
Witness accusations ‘within race’ more accurate than across race
Also more accurate with own age (unless exposed to another age consistently - e.g. teachers)
Factors that effect eye-witness memories
Perceptual stage (lighting, distance etc) Encoding stage (stress, violence, state of witness) Storage stage (decay, interference) Retrieval stage (misremembering, schema, questioning)
How perceiving an event for an eye witness could be dubious
Seeing the perpetrator more than 3 metres away on a full moon
How encoding an event for an eye witness could be dubious (2)
Noradrenaline narrows attention, peripheral aspects remembered worse (however also enhances memory of what is attended to)
Easier to remember an unexpected weapon than the carrier as the weapon is the threat
How decay of an event in memory could be dubious for an eye witness (2)
Forgetting curve shows sharp drop in memory after 20 minutes, falling for 2 days
Children forget faster than adults
How interference of an event in memory could be dubious for an eye witness (2)
Unconscious transference: correct memory assigned incorrectly in the line up
Proactive interference: knowledge or experience of a similar event confuses the details
How retrieval of an event for an eye witness could be dubious
Witness exposed to misleading information which alters memory (leading questions)
Personal or influenced opinion of the accused shapes how memory is told
Study on leading questions effecting memory retrieval
Whether asked if a car was bumped, hit, smashed etc effected the mph they guessed the car in the video was going at
Why witness line ups often go wrong
People have a tendency to choose someone even if they are not there, they then commit to the choice in court
Factors for a successful witness line up (5)
Make them look similar with similar clothes
Officer with witness does not know suspect (double-blind)
Emphasise that the criminal may not be there
Suspects shown one at a time so no pressure to choose
Record confidence statement after
Factors for a successful police interview
Report / record everything
Ask information in different orders for more detail
Recreate the context for better retrieval
Report / question from different perspectives
Do not interrupt interviewee
Ebbinghaus memory experiment (1895)
Participants tried to memorise nonsense syllables and he highlighted the shortcomings (he memorised 2000 himself)
Law of repetition for memory
The more rehearsal / recall the better memory, however rehearsals have a diminishing marginal return (learning curve)
Where memories are generally stored in the brain (2)
Temporary memory trace in hippocampus
Then integrated in cortical information networks
Multi-store memory model
information goes from sensory memory to encoded into short term (unrehearsed) memory and further encoding brings it to long-term memory. Retrieval brings it back to short term so in vulnerable for decay
Sensory memory
Unattended information that decays in milliseconds to seconds, but keeps information in mind to be attended to for further encoding
Different sensory memory stores (5)
Iconic (vision) Echoic (hearing) Haptic (touch) Olfactory (smell) Gustatory (taste)
Experiment for visual memory’s capacity and duration
Sperling presented 12 letters for 50ms, participants could name 4 on average. When queued by tone after the letters which row to say, they generally got most of them - indicating that almost all were stored in iconic memory but only some could be retrieved
Also found info to decay after 500ms, 250-500ms meant full report ??
Experiment on echoic memory
12 sounds presented in quick succession to test capacity and duration. Found large capacity for almost all sounds, retention between 2 and 4 seconds (longer than iconic memory)
Function of short term memory
Conscious processing of information, attention being necessary therefore is limited to the scope of the ‘spotlight’ (has an information bottleneck)
Chunking in short term memory
Grouping familiar or similar information for storage as single unit
Decay in short term memory
If information is no rehearsed, it will decay in 15-20seconds
Rehearsal in memory
The process of repetitively verbalising / thinking about information
Criticisms of short term memory component of the multi store memory model (4)
Does not account for information decaying (being forgotten) due to proactive interference from other stimuli (only suggests time)
Simple rehearsal doesn’t guarantee LTM encoding
Not only consciously processed info is encoded to LTM
Some patients have STM impairments but LTM works, so is the transfer the model suggests essential?
Retroactive interference and example
New material interferes with the already encoded
E.g. second language causes first to deteriorate
Alternative to the short term memory component multi store memory model
Split short term memory into four types of working memory: central executive (which all others link to), phonological loop, visuospatial sketchpad and episodic buffer. Gets round the problem that interference also causes forgetting
Function of long-term memory
Organises and stores information semi-permanently (unknown capacity and duration)
Principles that make STM and LTM distinct
Recency effect (more of last items remembered) is due to STM and primacy effect (more of first items remembered) is due to LTM. Middle items tend to be lost due to interference
Explanations for the recency and primacy effects (with middle items being lost) (2)
Recency being STM, primacy being LTM
Items at beginning and end are less interfered with
(research more)
Neurological evidence that STM and LTM are distinct
Double disassociations have been made with patient cases (some have impaired STM, not LTM. Others have impaired LTM, not STM.)
Central executive part of STM model
Attentionally limited, controls other components. It maintains goal related information to direct processing capacity to optimal functions
Phonological loop, its two structures and their functions
Temporary storage of speech like information
Structures: phonological store - passive, temporary store house with 2 second capacity (inner ear)
Articulatory loop - active rehearsal component linked to speech (inner voice)
Evidence for phonological loop (4)
Phonological similarity effect - error in memory likely to be phonologically similar to answer
Word length effect - memory for short words greater than for long
Unattended speech effect - irrelevant spoken material accesses phonological store
Articulatory suppression effect - rehearsal can be prevented by repeated articulation of a word / sentence (overt or covertly)
Articulation suppression effect and when its reduced
Rehearsal can be prevented by repeated articulation of a word / sentence (overt or covertly)
Effect is reduced when the rehearsed is presented auditory as has direct access to phonological store
Word length effect and reason for it
Word length effect - memory for short words greater than for long
Due to articulation duration, not syllables as words with same syllables and longer articulation still harder to remember (harpoon harder than bishop)
Visuo-spatial sketchpad component of memory model
A system for setting up and manipulating mental images (limited capacity)
Components of Visuo-spatial sketchpad (component of STM memory model) (2)
Visual cache - visual information about shape and colour
Inner scribe - spatial and movement information
Experiments on visuo-spatial sketchpad (component of STM model) (2)
More likely for a rabbit to have whiskers in imagination when picture next to fly rather than elephant
Evidence shows people mentally put themselves in location when imagining route of travel
Tasks of central executive (component of STM model) (4)
Directing attention, updating information, shifting between strategies, selecting inhibitions
Evidence for central executive (component of STM model)
Dysexecutive syndrome - frontal lobe damage impairs central executive function (can also cause catatonia - remaining motionless for hours)
(also found in Alzheimer’s patients)
Episodic buffer (component of STM model)
Intergrates information into a single complex structure, holding around 4 differing types in multidimensional code (smell, sound, visual etc) - binds and makes sense of sensory input
(Phonological loop and visiu-spatial sketchpad link to it)
Implicit memory and other name
Memories that cannot be explicitly retrieved (consciously), for example motor memories etc. Individual has a passive role
Also called non-declarative
Explicit memory and other name
Actively, consciously recalling the memory with language
Also called declarative
Examples of explicit memory test (3)
Free recall, cued recall, forced choice recognition
Examples of implicit memory tests (2)
Lexical decision, word fragment completion
Example of questions that elicits an explicit and implicit memory response
Explicit: what word is paired with car?
Implicit: what comes to mind when I say car? - no awareness memory is being used
Causes of amnesia (6)
Parkinson's Acute virus infections Brain re-sectioning for epilepsy treatment Korsakov's syndrome Head injury Psychological disorder
Effect after removal of bilateral medial temporal lobes (including hippocampus)
Anterograde amnesia: unable to make new, explicit (largely episodic) memories. Could retain information for several minutes and had a working implicit memory (e.g. riding a bike)
Brain areas thought for implicit memories (5)
Basal ganglia Cerebellum (for motor) Ventral thalamus Substantia Nigra Premotor cortex
Brain areas within the medial temporal region (5)
Hippocampus Amygdala Entorhinal cortex Parahippocampal cortex Perirhinal cortex
Brain areas thought for explicit memories (3)
Medial temporal region (especially hippocampus)
Frontal cortex
Connections between temporal region and frontal cortex
Example of impaired implicit memory, with explicit intact
Man in his 70’s with Parkinson’s with a primarily damaged Basal Ganglia. He cannot repeat habits and skills but can remember facts and stories
How we know implicit and explicit memory are separate systems
Patients have been found to create a double disassociation (though most have partial damage to both)
Types of explicit memory (2)
Semantic (general knowledge, no time/place)
Episodic (recalling past experiences or recognition from them)
Semanticisation
Episodic memory becoming a semantic one, the experience where knowledge was required being irrelevant
How we know semantic and episodic memory are separate systems
Double disassociation:
Semantic dementia (anterior temporal lobes damage)
Patient after bike accident had specific episodic impairment (no context behind knowledge)
Procedural, implicit memories
Automatic performance of certain actions that have been repeated before (skills, e.g. walk into university)
Priming
Reacting to stimuli in learnt way from previous encounters - happens implicitly and can be semantic
What happens faster, procedural or priming memories
Priming memories
Outline a neurological priming study
Brain area is less active after priming than if no priming as it takes less processing if stimuli is familiar
How forgetting takes place (2)
Decay of memories over time
Interference from similar stimuli / events
Process of consolidation
Memory trace temporarily stored in hippocampus, then is transferred to cortex for long term storage if it does not decay
Anterograde amnesia
Can form no new memories, caused by damage to the hippocampus (generally)
Why patients with anterograde amnesia sometimes have retrograde amnesia for the time just before surgery / being diagnosed
When the hippocampus is damaged too much memories are no longer able to consolidate memories into the cortex. Anything before has been consolidated therefore remembered in the intact cortex
How to improve the consolidation process
Sleeping is evidenced to as there is no interference whist asleep
Dementia
General loss of function caused by cell death, memory often being a primary loss
Possible symptoms of dementia (6)
Memory impairment Aphasia (language impairment) Apraxia (motor skills impairment) Agnosia (sensory memory impairment) Executive function impairment Social impairment
Difference between degenerative and non-degenerative dementias
Degenerative have a degree of genetic cause (e.g. Alzheimer’s), unlike non-degenerative (have a diverse origin)
Memory impairment in Alzheimer’s (3)
More difficulty retaining new information, episodic memories and explicit memories
How the brain degenerates in Alzheimer’s patients
Generally from the outside inwards. Entorhinal cortex often worst hit, which links the hippocampus and neocortex
Brain areas commonly damaged in Alzheimer’s patients (4)
Entorhinal cortex
Limbic cortex
Inferior temporal cortex
Posterior parietal cortex
Symptoms of (i) early (2) (ii) middle (2) and (iii) late (3)Alzheimer’s
i) Needs reminding, loss of concentration
ii) Gets lost easily, personality changes
iii) Severe confusion, personal care, lack of recognition of self and others
Semantic networks
For language, the brain categorises words into these association links, forming a complex structure of groupings
Evidence for semantic networks
Sentence verification tasks: ‘a robin is a bird’ is verified faster than ‘a robin is an animal’
How are semantic networks organised and example
By their semantic relatedness depending on ones own experience
‘A robin is a bird’ verified faster than ‘a penguin is a bird’ as the latter is generally more abstract
Evidence against semantic networks
Life is too complicated for such a simple structure as words hold multiple definitions and meaning (e.g. games). It is probably similar in principle but more complex
Experiment on if word meaning or comprehension processed first
People detect ‘London buses are white’ and ‘London buses are sour’ as false with the same amount of time - showing meaning and knowledge processed simultaneously (sour being impossible and white being semantically false)
Parsing
Figuring out links between words during sentence analysis (based on context)
A schema about events if often called…
A script
Advantages of schemas / scripts (2)
Capture commonly encountered aspects of life so expectations can be formed in the future to conserve the energy of detailed attention
Can draw inferences from new events based off expectations
Types of inferences in language (3)
Logical - based on word meanings
Bridging - established coherence from current text and preceding text
Elaborative - makes use of world knowledge for coherence
Inferences in terms of language
Contexting sentences / words through schemas and scripts
Theories for inferences in language (3)
Constructionist - numerous elaborative inferences made automatically
Minimalist - some automatic inferences but only local ones
Depends on individual differences of person’s ability
Local inference in language
Inference from one sentence to another
global inference in language
Integrating overall text with an inference
Aphasia
Impairment of language comprehension and/or production
Broca’s aphasia, cause and other name
Impairment of language production, with poor syntax. Caused bu frontal lobe (Broca’s area) damage
Also called non-fluent aphasia
Wernicke’s aphasia, cause and other name
Impairment of language comprehension, with lack of meaning but vague grammar. Caused by temporal lobe damage
Also called fluent aphasia
Anomia
Impairment in the naming of object (either semantically or phonologically)
Most aphasia patients also have this
Experiment on anomia patients
Divided them into more phonologically or semantically impaired and recorded ERP’s during naming task
Phonological group had abnormal ERP’s until 450ms (phonological encoding time), semantic group had much quicker abnormalities representing semantic processing
Shows both are at play in anomia
Agrammatism
Patients know words but cannot put them together in correct structure, linked to a damaged Broca’s area
Where Phrase structures in language are processed
in frontal operculum and anterior superior temporal gyrus
2) relationships between sentence elements processed in Broca’s area
3) integration of lexical and syntacti
Where relationships between sentence elements are processed
Broca’s area
Where integration of lexical and syntactic information is processed
Posterior superior temporal gyrus
Experiment on syntactic processing in language
Aphasic patients with damage to pathways linking Broca’s and Wernicke’s area were impaired at syntactic tasks more so than patients with damage to the areas
Shows syntactic processing not dependent on one region but the pathways linking
Psycholinguistics
Studying the relationship between linguistic behaviour and psychological processes
How psycholinguistics is usually researched (3)
With EEG and various reading tasks and eye tracking
Garden pathway model for syntactical structure
The simplest structure is initially considered for any sentence - syntactic analysis done before and semantic knowledge used to make sense needed
Constraint-based model for syntactic structure
Syntactic and semantic information processed at the same time, with grammatical knowledge containing interpretations
Interpretations differ based on experience (expectations)
Cloze probability
Likleihood of a word occurring in a particular context (based on semantic knowledge / expectations)
Experiment on processing of fiction
Context can be changed to expect fictitious things. A larger N400 (prediction error) to a peanut being salted than to a peanut being in love when a love context was stressed beforehand
How the rate of learning help learning
More time spent the better the retention (law of repetition)
How distributing practice can help learning
Short and regular learning is better than occasional cramming as there is time for consolidation
Rote learning, and is it effective for learning
Simple repetition of information to increase its time in working memory
Studies indicate it is not very effective for retention
How testing and feedback can help learning
Bringing information into consciousness oneself very effective for learning (studies show). Feedback helps correct persistent errors
Generation effect for learning
Better memory if answer is thought yourself
How motivation can help learning
Increases time and attention however has no individual effect if these are the same
How arousal (energy levels) help learning
Optimal learning is at medium arousal, the curve looking like an n. However implicit learning is not effected by arousal
How meaningfulness of material can help learning
The more meaningful (e.g. related to what is known) it is easier to learn
Organisation principle for learning
Memory functions by relating things/events together
How duel recoding helps learning (and what it is)
Information recoded and stored with a different sense or in a different way. Can be accessed in more ways so helps learning
Study shows better memory if word paired with image
How studying with a friend can help learning (3)
Listen to new insights
Explaining helps understanding
Information can be retrieved from memory of conversation
How level of processing effects learning
Shallow processing of ‘shark’ (‘starts with S’) is remembered worse than deep processing (‘type of fish’),
(does not apply for implicit memories)
Elaborative rehearsal principle for learning
Connecting information with existing knowledge makes it more memorable (context application)
Retrieval cue in learning
Information that allows access to a memory trace, these vary in strength depending on experience (how many activations etc)
How experiences are remembered
Accessing a fragment (retrieval cue) of it as a key to the whole
Cue dependent forgetting
When a memory is stored but cannot be accessed
Encoding specificity principle in memory
Each item is encoded with respect to the context it is studied in, meaning better retrieval when the cue matches the trace
Subtypes of retrieval (4)
External / spatiotemporal
Physiological
Mood dependent
Cognitive context dependent
Evidence for external / spatiotemporal retrieval
Retrieval better in scuba divers when they retrieve a memory from underwater, underwater
Evidence for physiological retrieval
Retrieval higher of drunk events after consuming alcohol compared to placebo
Evidence for mood dependent retrieval
Memory of something learnt whilst happy is retrieved better when happy (study done with music as mood changer)
Evidence for cognitive context dependent retrieval
Bilingual people better at retrieving when information was learnt in the same language
Ways of forgetting (3)
Transience - les accessable overtime
Absentmindedness - processed shallowly
Blocking / interference by something else
Ways that memory can be distorted
Misattributed to wrong source
Through suggestibility - others providing external bias
Personal bias of schemas
Sins of memory
Forgetting
Distortion
Intrusive recollection
Intrusive recollection
A persistent memory that cannot be forgotten when wanted to be
Why do we have inaccurate or dysfunctional memories
Overall the systems in place have evolutionary importance. it would be impractical to remember everything and potential damaging to remember it all accurately
In what way does a memory fade
To a point where one gets the ‘gist’ of the memory but not the detail (efficient), if not completely faded
Transience of memories and what effects it (2)
Memory becoming less accessible overtime without retrieval
Interference and amount of ‘work done’ effects it
Change blindness and effect on memory
Inability to notice subtle changes to a whole, memory reconstructs what it expects to see therefore not attending to changes
Prospective memories
Are event and time based (difficult for the absentminded)
Blocking in memory
Temporary interference of information by similar but incorrect items
Part-set cueing in memory and its cause
Disruption of retrieval plan or blocking by related information
Causes the tip of the tongue state
Characteristics of tip of the tongue state
Common with names and obscure words
Increases with age
Part of word often remembered (syllables or 1st letter)
The value of blocking in memory
Mass confusion if all the information associated with the retrieval cue came at once
Source amnesia in memory and cause
Forgetting true source of information but remember information
Causes the sleeper effect: initially untrusted info due to source later believed
Misattribution in memory
Memory present but attributed to wrong source
Criptomnesia in memory and cause
Having the wrong source for information and no experience of remembering
Causes unintentional plagiarism, thinking an idea is yours when it isn’t
Deese-Roediger-McDermott paradigm in memory
Words very systematically remembered, experiment shows words not remembered are filled in with phonologically or schematically similar words - equally as confident in them
Factors contributing to false memories (4)
Older participant
Damaged frontal lobes
Many possible associations
Low recallability of thing
Factors contributing to less false memories
Pictures shown instead of words
More emotional connotations
Damage to medial temporal lobes (involved in schematic ‘gist’ of memory)
People with false memory tendencies also often… (2)
Disassociate experiences (day dreams that feel real) Are high in creative imagination
Example of study highlighting suggestibility of memories
Photoshopped balloon ride picture of them as child and many remember it
Value of personal bias in memory
Fitting things to schema makes ones life story more coherent
Value of persistent memories
Recall traumatic events for survival purposes in future
