Midterm 1 Flashcards
What is cognition ?
The collection of mental processes and activities used in perceiving, thinking, remembering and understanding, and the act of using those processes
Cognitive science ?
A term designating the cross-disciplinary study of cognition, typically includes psychology, linguistics and computer science (plus others)
What is cognitive psychology?
“Refers to all the processes by which sensory input is transformed, reduced, elaborated, stored, recovered and used “
Who is Wilhelm Wundt?
Set up first psych lab to study mental phenomenon
- interested in conscious mental events
- extensive use of introspection (self observation of the mind)
Problems with introspection?
Different results for different individuals
-individual differences unrelated to the phenomenon (some might have a better vocabulary and describe the process more clearly)
-Very subjective (science will become a matter of opinion, not fact)
-can’t be tested
-responses cannot be verified
-unable to study anything that is not available to consciousness (unconscious thought plays a huge role in our mental lives)
-
What is behaviourism?
What’s the problem with it?
-John Watson
-said that psychology should only study external observable events (objective measures of behaviour)
-consciousness is neither a definite nor an unstable concept
Radical behaviourists rejected the idea of studying the mind or mental processes and cognition was suppressed
-measurable, recordable, physical events
Problem: subjective entities play a pivotal role in guiding behaviours, and so we must consider these subjective* entities if we want to understand behaviour
-what does the stimulus mean to you?
What is the cognitive revolution (3 aspects)
3 parts
- Growing dissatisfaction with the mind and mental processes (we must focus on our understanding* of the stimulus and not just the stimulus
- WW2
- technological advancements
- study of human interaction with machines (needed info about human decision making ) - Chomsky ripped apart BF Skinners book Verbal Behaviour. People saw that he was right
- we need to study mental processes indirectly, relying on the fact that these processes, themselves invisible, have visible consequences: measurable delays in producing a response
What is the information processing approach?
- Analyzing cognition into a set of steps in which an abstract entity (information) is processed
- study the structure* and function* of professing within a given context
- encoding, storage and retrieval of information
- sensory memory>STM>LTM (information processing model)
- > info flows through systems and may get changed/transformed
What are the assumptions of cognition (3)
- mental processes exist and can be studied
- > transcendental method* or “inference to best explanation” (inferences about the unobservable processes based on observable facts
- mental processes and structures are revealed through 2 basic measures (rxn time and accuracy measures)
- humans are active processors
What are some cognitive methodologies?
- need to be specific and objective
-preference for experimental study (control and manipulation of variables, isolating causal effects)
-studying the unobservable (role of inference, assumptions regarding processing)
(Methodology is one thing that continued from behaviourism )
Which part of the brain are cognitive neuroscientists mostly interested in?
The forebrain
- involved with higher order processing
- consists of cerebral cortex(outer surface and grey matter)
- two hemispheres joined by corpus callosum
- 4 lobes
List 3 subcortical structures
Thalamus -sensory relay station
Hypothalamus-controls behaviours such and eating, drinking and sex
Limbic system -hippocampus, mammillary bodies, amygdala (plays role in learning and memory and emotion)
Describe ERPs
Event Related Potentials
- electrical activity on the scalp
- patterns of positive and negative voltage
- *localization of activity/function but no structural information (we don’t know where exactly in brain activity is occurring-can’t go inside head)
- peak difference(automatic/involuntary response)
Describe a CAT or CT scan
Computerized Axial Tomography
- series of x-rays taken at variety of angles then reconstructed in a computer to form an image
- Allows for the study of *anatomy and structure but not function (no info on brain activity)
- tells us shape, size and position of structures within brain
Describe PET scans
Positron Emission Tomography
-measures blood flow, usually via a radio active glucose tracer
-*Measures brain activity over time (not instantaneous)
-how much activity is happening in different areas (normal vs mild cognitive impairment vs Alzheimers)
-finer resolution but not instantaneous
Starting to have both anatomy and function
-tells us what regions of brain are particularly active at any point in time
Describe MRI and fMRI
Magnetic resonance imaging(static picture)/ functional magnetic resonance imaging (pictures over time-activity)
- use of a giant magnet to measure fluctuations in magnetic fields
- fMRI measures rapid changes in blood and oxygen flow in brain areas and helps determine *”localization of function”
- precise images
- colour= activity
- fMRI-moment by moment activities
Describe TMS?
Trans cranial Magnetic Stimulation
- series of magnetic pulses to temporarily disrupt function or “turn off” specific brain regions
- also used to treat depression
What are some limitations to studying brain damage?
If the cases aren’t “pure” case like HM, small sample size, cause of damage, predamage and level of functioning, etc
Describe Broca’s aphasia
-expressive aphasia where they understand what you’re saying but can’t respond
-they understand their deficits
-Tarzan speech but no grammar
(Better one to have)
-located in left
hemisphere
-problems with speech production
Describe Wernicke’s aphasia
- receptive aphasia
- difficulty understanding when you talk to them (they think you’re the one with the problem)
- speech is often a “word salad” (correct syntax but no meaning)
- can even make up words that seem to make sense in their header
What’s the first memory system?
Sensory memory
- an extremely brief, temporary store of information coming in via senses
- often totally unaware of it
- *visual persistence effect(visual light trails ) ie sparkler trails
What is iconic memory?
Visual sensory memory
- Sterling’s *partial report technique (info briefly presented to participants)
- iconic store is large but holds items *very briefly
What is Echoic memory?
Auditory sensory store/memory
- partial report technique
- echoic store is large and items held longer than the iconic memory store (although still brief )
- likely Because auditory information spread over time-needs a slightly larger store
- both stores allow info to be held briefly before it is processed and recognized (allows us to catch up on anything we missed)
What is pattern recognition
Identifying or categorizing objects in the environment
(Can be visual, auditory, etc)
-we can recognize variations in different patterns (ie different sizes or styles)
-able to recognize objects when only partial info is available
-recognition faster/more accurate if context is appropriate
What’s the template matching theory?
One theory of pattern recognition
- identify patterns by comparing the pattern of neutral excitation with patterns or “templates” stored in memory
- perform a *holistic match between stimuli and the representations in memory. Ie barcodes
What is visual agnosia?
The inability to recognize objects and use them correctly
What is Feature Comparison theory?
One theory of pattern recognition
-examine the objects features to determine what the object is
Break object into parts or features -recognition based on processing different features
What is Selfridge’s Pandemonium Model?
One theory of pattern recognition
- one of the earliest feature models
- letter/word recognition
- multiple levels of demons are shouting
- each level recognizes more complex features and feeds information to higher levels
- the top level recognizes the letter as an A
What is apperceptive agnosia
Patients seem able to see an objects shape and colour and position, but they cannot put these elements together to perceive that intact object
Ex. Dr. B.F. Can’t draw objects from model but can objects from memory
What is associative agnosia
They see but cannot link what they see their basic visual knowledge(ex. Dr. D.F. Who mistaken his wife for a hat)
What are advantages to feature theories
Possible to identify the relations among features that are critical for identifying a given letter
- features are simpler than templates and could more easily account for variability in stimuli
- need to store less information, more efficient ( don’t need to store 1,000,000+ templates)
What is the evidence for features
-Visual search studies
>easier to locate a target defined by a single feature
> search asymmetries
-Neurological data
>neurons that fire in response to specific stimuli or features (slanted lines)
Tachistoscope ?
Device that allows presentation of a stimuli for precisely -controlled amount of time
What’s a post stimulus mask
Letters or symbols perceived after the stimulus, serves to disrupt any sensory memory
(Allows the researcher to determine how much the participant can discern in a brief presentation )
What is recognition threshold
Length of exposure to stimulus necessary for recognition
-will vary with the nature of the stimuli (how easy/difficult it is to detect)
What’s the word frequency effect
Determines how easy/difficult a word is to detect (more frequent encountered words detected more easily )
What is repetition priming
More recently viewed words easier to recognize
The word superiority effect
More accurate in identifying a letter if it appears in a word (identify the word first and then the letter)
What is the degree of well-formedness
Word superiority effect only occurs if the letter appears within a context that obeys the rules of language
-pseudowords (could be a word, follows rules of language and could be pronounced)
Hdjdud vs. glake
What are feature nets?
Layered network of detectors
- first layer detects simple patterns or features, each subsequent layer detects more complex patterns
- each detector has an activation level which is increased when the detector receives input
Response threshold
The activation level at which the detector responds
Baseline activation ? And what determines baseline
The detectors activation level prior to any inputs
- resting level
- determined by how recently it has fired(more recent=higher baseline), how frequently it has fired more (more frequent=higher baseline)
Bigram detectors
Detectors of letter pairs
Some letter combinations are more frequent than others, have higher baseline activation and require less activation to reach response threshold
What are PDP models/connectionist models?
Parallel distributed processing models
-knowledge of spelling patterns “built into” the network
Distributed-everything we know about letter C is distributed across multiple detectors. System can be damaged and can still recognize c words
What is the revolutionary model by McCelland and Rumelhart?
Feature based/connectionist model of word recognition
- network of connections
- no bigram detectors
- excitatory and inhibitory connections
- flow of activation (includes top down activation)
What is recognition by components (RBC)? What are geons?
Geons are building blocks of all objects and can be distinguished from many viewpoints
- geons are simple shapes such as cylinders cones and blocks (intermediate level of detectors)
- can be combined in various ways to create all the object we perceive
RBC model:
Feature detectors at lowest level-perception of basic properties
Geon level-identification of component parts
Higher level sensitive to geons assemblies(combination of geons)-activation feeds up from lower levels
Activate “object model”-recognition of complete object
-viewpoint Independent, no matter what your position is relative to the object, you’ll be able to identify its Geon’s and thus identify the object
What’s the restoration effect?**
Can delete sounds from a recorded speech, replace them with noise.
-participant fills in what ought to be there and reports hearing the complete word plus the noise
What area is specialized to process or recognize faces
Fuiform face area (FFA)
-strong dependency on orientation
What is attention
Refers to the allocation of resources(The concentration of mental efforts on sensory or mental events)
-we cannot process everything we must divide up our processing resources
What are the four functions of attention
Selective attention -Focus on some stimuli and ignore others
Vigilance and signal detection-did a signal occur?
search-Scan for a particular stimulus
divided Attention-able to perform multiple tasks concurrently
What are shadowing studies
Participant repeats or shadows auditory messages
What is a dichotic listening task
Two messages, attended and unattended channels. Often paired with shadowing task
-we are good at ignoring stimulus it asked to and there is some evidence that somethings still get through anyway but typically unaware of its physical attributes
What is the attentional blink
-shows capacity limitations (bottleneck)-I narrowing in our system
-observed with the RSVP technique
(rapid serial visual presentation)
-detect a specific target and perform second task at the same time. Second task becomes more difficult after presentation of the first target, as if our attentional eyes are blinking/closed. Attention system recharges/resets
Describe negative priming
When you’re told to ignore something, you get slower and not faster, because you’ve practised ignoring it
-look for the red pen and ignore other pens… then once asked to find the blue pen, you’re slower
Early theories of attention/bottleneck theories
- many early theories suggested we filter out the unattended channel.selected which channel to attend
- simple filtering could not account for all the experimental data
Change blindness vs inattentional blindness
Change blindness: failure to nitice a change in environment
(As they are occurring)
Inattentional blindness: failure to see visible objects when your attention is directed elsewhere (in the moment)
-not paying attention to a stimulus
Two-part theories of attention
1) Block/filter the processing of distractors
- consistent with previous research and theorizing
2) promote the processing of desired stimuli
- Newer motion
How can you prepare for the location of a signal
- selective priming
- spatial anticipations
- consistent vs. Inconsistent cues
Attention as a spotlight metaphor
-You can narrow or broaden the focus/beam and can shine the beam at different places. You can move it around the scene. But at what cost? Takes time to lock and unlock attention
What are exogenous cuse
-generated from the outside, trigger bottom up processes
-eye-catching stimuli. Not all attention this deliberate.
-warning or emergency signals are designed to capture attention with rapidly changing and distinct stimuli
example roadsigns and advertisements
Describe divided attention
Can split attention between multiple inputs/tasks but have limited resources and a cognitive budget
General resources versus task specific resources
-revealed by brooks 1968 through divided attention tasks
-drawing on the same task specific resources causes interference and more demand
Practice and automaticity influences on resource demand
Practice can greatly decrease the resource demand of a task
-can go forward without awareness
-process becomes more automated/automatic you don’t have to think about them and devote resources and attention
Ex. Driving (at first uses many resources and then becomes unconscious process)
Why isn’t everything automatic (like reading)
Because there are some disadvantages to automaticity
-there is a loss of flexibility. *
-Cannot alter, change, or stop fully automatic process which can be a source of error
(example. stoop test)
Error:
-mindlessness (driving home by accident)
-slips associated with automatic processes
-advantage of freeing up resources but there is still a trade off
Compare automatic processing with controlled processes
Automatic processing :
- without intention
- not subject to introspection
- use few resources
- occur rapidly, often effortlessly
Controlled processes:
- with intention
- are subject to introspection
- use many resources
- are often a slow, effortful process
Why is it hard to do tasks such as tapping your head and rubbing your tummy
- due to cross talk between channels
- The two signals of them are not separated and distinct from each other and signals get intertwined
- have to practice keeping those to mine separate to do them efficiently, requires channel segregation
- there is a cost to multitasking, dividing attention -potential interference between tasks especially if the tasks use the same resources or if they’re less automated tasks
- one exception is walking and talking
What’s the importance of executive control
Executive control tells you when to allocate resources to one task or another
- it sets goals and priorities, selects strategies and directs cognitive functions.
-It’s important for divided attention and other attention base to tasks.
-Maintains current goal.
Inhibits habitual/automatic actions
What are the three networks for visual attention
Alerting network, orientating network and executive control network
Describe unilateral extension and unilateral neglect
-exaggerated tendency to orientate to one side and not to attend to the other side
Neglect- worse one to have, totally ignore one side
Extinction-can be taught to move plate to other side
ADHD
Disorder of attention that many say is not a pure attention problem
- can hyper focus
- also includes impulse control, some behavioural problems
Sustained attention response task
- Vigilance or continuous performance task
- often used for ADHD
- extremely taxing /difficult
- often used to detect subtle attention deficits
What is PASAT
- Paced auditory serial addition task
- test for divided attention
- very difficult and frustrating
Describe digit/letter scan or cancellation tasks
- May reveal a variety of attention deficits, including visual neglect
- can use visual or auditory stimuli
Baseline activation ? And what determines baseline
The detectors activation level prior to any inputs
- resting level
- determined by how recently it has fired(more recent=higher baseline), how frequently it has fired more (more frequent=higher baseline)
