Quiz 2 Flashcards
Bottom up processing
processes that directly shaped by stimulus
Can bottom up processing explain everything?
NO
-Apperceptive agnosia: (V1) impaired early vision, unable to recognize basic features
-Associative agnosia: impaired late vision, can see object/draw, but can’t recognize/name
How is perception constructive
affected by assumptions about the context
(e.g. stimulus + env)
Top-down processing
knowledge/expectations that influence and enhance interpretation of sensory input
Examples of knowledge/expectations we use in top down processing
Context and Experience shape perception
Why are features important?
Helps in visual search tasks (examine a display and judge whether target is present)
-slower w/ combination search
Word Recognition
Tachistoscopic presentation (flash word quickly, then cover w/ random word and then ask about recognition of words)
Word recognition is better with which conditions?
-high frequency words (recognized in tachistoscopic)
-primed high frequency words
-primed low frequency words over unprimed low frequency words
as long as high frequency and/or primed
How do we recognize words?
-word superiority effect
-well formedness
-feature nets
Word Superiority effect
remember/recognize entire words better than single letters
Feature nets
-driven by bottom-up (sensitive to external stimuli) and top down (recency effect/priming)
-can be used w/ well-formedness
Well-formedness
how closely letter sequence conforms to typical patterns of spelling in language
(e.g. HZYQ vs FIKE vs HIKE)
-may be prone to errors because of this
Detectors of feature nets
- feature
- letter
- bigram
- word
-each receptor has starting activation level (affected by recency & frequency)
-input increases activation
-firies when response threshold reached
-NOT neuron (rather could be represented by network of neurons/neural tissue)
important aspects of feature nets
-knowledge is distributed (increase neuronal firing=correct)
-sacrifice perfect accuracy for efficiency
-more advanced feature nets have connected mechanisms (top-down, bottom up. lateral connections)
Feature nets for objects
- feature detectors
- geon detectors
- geon assemblies
- object model
(use about 30 geons to create objects)
Face perception
face inversion effect=something special about faces
-make more errors w/ inverted faces compared to inverted houses
-more extensive experience, unique processing strategy
Prosopagnosia
cannot recognize individuals face- but have good vision+memory
Super-recognizers
identify faces amazingly well (recognize years later)
Perception (imagery) and brain areas
-areas (face-inferotemporal, places-hippocampus) used for early visual processing are ALSO active during visualization imagery
-disruption (natural or TMS) affects vision AND imagery
Individual differences in imagery
change in frequency is due to the level of vividness of imagery (more vividly you image=more change in frequency)
Visual imagery
involves experience of seeing
Spatial imagery
involves moving through space
Visual VS Spatial imagery
Strengths of Visual: career in arts, emotional processing
Strengths of Spatial: science, reliving memories
Attention
- cognitive mechanisms that combine to help us select, modulate, and sustain focus on information that might be most relevant for behaviour.
- capacity-limited
- directed externally or internally
Dichotic Listening
- people cannot recall the semantic content of the ignored channel but are aware of changes in physical features (e.g. pitch)
Cocktail party effect
exception of dichotic listening- your name or other meaningful words
how can we explain general insensitivity to the unattended channel and also information that leaks through?
- we block unattended inputs with a filter: blocks potential distractors, attended inputs are not filtered out
theories of attention need to..
- explain how we inhibit new or unexpected distractors
- explain how we promote the processing of desired stimuli
inattentional blindness
the failure to see a prominent stimulus, even if one is staring at it
- the object their eyes are focused on can change shape (central object), it changes and goes back quickly, so most people fail to notice
change blindness
the inability to detect changes in a scene despite looking at it directly
- affected by age, cloudy mind, etc.
inattentional and change blindness causes
a failure to perceive the stimulus (early selection hypothesis)
a failure to remember the stimulus (late selection hypothesis)
early selection hypothesis
- only the attended input is analyzed and perceived
- unattended information receives little or no analysis (never perceived)
late selection hypothesis
- all inputs are analyzed
- selection occurs after analysis
selection may occur before consciousness or later (unattended information might be perceived, but is then forgotten)
early selection evidence
- electrical brain activity for attended inputs differs from activity for unattended inputs within 80 ms.
- no way that it can be entirely processed in this little time- selection can happen
late selection evidence
- stimuli that are not attended to can nevertheless affect the perception
- example: two black lines, with the arrows going different ways, one is viewed longer than the other
mechanism of selection
Selective attention biases the competition in favour of one stimulus over the others
biased competition can occur due to bottom-up selection (what am i seeing) and/or top-down selection (is that something i have seen before)
bottom-up selection
the brain processes sensory information and uses clues to understand stimuli
top-down selection
our brain utilizes existing knowledge and expectations to interpret new sensory information
selection via priming
expectation or experiences priming
repetition priming
expectation-driven priming
expectation priming
our expectations and experiences can prime the appropriate detectors (specific stimulus, the input channel, etc.)
repetition priming
priming produced by a prior encounter with the stimulus (bottom-up
expectation-driven priming
detectors for inputs you think are upcoming are deliberately primed (top-down)
spatial attention
your ability to focus on a specific location in space
Posner cueing task cues can be
- endogenous or exogenous (arrow-choice vs. box lit up-grabs your attention)
- valid or invalid
Results
- no cue- fast response
- valid cue- even faster
- invalid cue- much slower
unilateral neglect syndrome
- shows how space-based attention can become object-based
- first, only report seeing red, the patient watches it switch, the patient can then see both sides
cost of repetition priming
none- already highly active
cost of expectation-based priming
- unexpected things suffer
- requires mental resources
- you have dedicated mental resources to other things, you need to readjust
- this reveals the presence of a limited-capacity system
attention as a spotlight
- can be moved anywhere in the visual field
- scope can be widened or focused (has implications for what is enhanced or suppressed)
Attention movements
- attention can move independent of the eyes
- its effects are faster than eye movements
- overt vs. covert attention
overt attention
attention aligns with eye movement
covert attention
paying attention to things you are not looking at
what we attend depends on the goal
- eye movements (free examination, materials, ages, etc.) you will look different places depending on the goal
attentional control system
spotlight metaphor is too simplistic for what we actually do
- orienting system, alerting system, and executive system
orienting system
- moving attention
- disengage attention from one target, shift attention to a new target, engage attention on the new target
alerting system
- maintaining attention
- maintain alert state in the brain
executive system
- control voluntary actions
attention solves the binding problem
incorrectly bind: was there a black vertical line? may say yes due to conjunction error, attention allows for us to bind both correct and incorrect features together
feature integration theory
pre-attentive stage and focused attention stage
pre-attentive stage
- parallel processing of the stimulus
- efficient
- all you need is to look at the screen- one red, it would pop out, not turning on attentional spotlight
focused attention stage
- expectation-based priming created processing advantages for the stimulus (wheres waldo)
- adding more dimensions- more careful attention- focus attention and develop expectation- scan the screen
divided attention
- task switching is divided attention
- the skill of performing multiple tasks simultaneously
- limited by availability and overlap of the mental resources
Task: repeat a list of words
repeat what you heard: a lot of errors, same language processing centre, auditory information
shown words: fewer errors, less overlap, auditory and visual
pictures- even fewer errors
task novelty
important how new a task is, cognitive demand, if you practice it requires less attention
lights missed
- missed more lights when on phone
reaction time
- slower reaction time when on phone
highway navigation
- less successful simple highway navigation when on the phone than with someone in the car
executive control
the mental resources and processes that are used to set goals, choose task priorities, and avoid conflict among competing habits or responses
task interference
- tasks will interfere with each other if their combined demand for a resource is greater than the amount of the resource that is available
- between-task interference increased as task similarity increased
- interference is also evident even when concurrent tasks are quite different
practice helps
- practiced skills require fewer resources or less frequent use of resources
- well-practiced tasks lead to automaticity
- e.g. stroop interference can be reduced with practice
practiced skills
- leads to a decrease in interference between tasks
- reduces (diminished) need for executive control
the modal memory model
incoming information- sensory memory- short-term memory (maintenance via rehearsal or lost)- long-term memory- short-term memory (retrieval)
sensory memory
Example: view word grid for 50 ms, then recall each letter freely, or instructed to recall a specific row
we know it exists, but it is not really that important to our study
short-term memory
- should instead be called working memory
- a dynamic form of short-term storage
- better undertstood as a status or activity rather than a place
features of working memory
duration: temporary, fragile
capacity and size: limited
ease of entry: relatively easy
ease of retrieval: relatively easy
features of long-term memory
duration: long-lasting, enduring
capacity and size: enormous
ease of entry: effortful
ease of retrieval: can be difficult, slow, and unsuccessful
evidence supporting the modal model
- recency and primacy effect
- we should be able to manipulate working memory or long-term memory separately
recency effect
last few items are still in working memory at time of recall
primacy effect
opportunity for memory rehearsal increased chances of transfer to long-term memory
30 second filled delay
no longer have recency effect
slow presentation
if you give people more time to rehearse the words, they are more likely to remember them
function of working memory
- used whenever multiple elements or ideas are combined or compared in mind
- individuals can differ in working memory capacity
- digit-span task revealed a 7+/-2 chunk capacity (can mean different things for different people, e.g. phone number in three sets of digits)
- operation span task assess working memory capacity while its working- more accurate and correlates with lost of interesting metrics. (using appropriate measures, reading, operation, problem solving, etc.)
- some of us can work on our memory more better than others
entering long-term storage
two types of rehearsal: maintenance and relational
maintenance rehearsal
repetition- reading over and over
relational or elaborative rehearsal
thinking about the meaning of words, and connections, taking information and situating it with information already in the long-term memory
- far superior to maintenance
depth of processing
shallow and deep
shallow processing
superficial engagement with the material
no meaning, only physical characteristics
e.g. is the word DOG in capital or lower-case letters?
deep processing
requires thinking about the meaning of the material
e.g does the word dog fit in the sentence “he walked his___.”?
intention to learn
- doesnt matter- if you are giving them a test, pure awareness of the fact of being tested or the attention of learning them makes no difference- intentional
surprise test- incidental learning
deep processing- more connections
more connections- more pathways to specific memory
Attention to meaning involves thinking about relationships
- ROY G BIV- mnemonics- strategies to enhance our memories based on superficial aspects of the word
acquisition, retrieval and storage
- not easily separable
- effective learning depends on how the information will later be retrieved
- new learning is grounded in previously learned (stored) knowledge
