Unit 4 Flashcards
Attention
Cognitive mechanisms that combine to help us select, modulate, and sustain focus on information that might be most relevant for behavior
Perceptual Gating (Selection)
Only so much sensory information can be processed by our brain so conscious perception is always selective
But selection is not always conscious
Load/Capacity Limitation
We have a limited ability to carry out various mental operations at the same time depending on how difficult the task is
There is only so much attention we can use on a task
Load
How difficult a task is
Capacity
How many resources are available for an individual to perform the task
ie. ie having a cold vs being healthy when taking an exam
Effects of Distraction on load and capacity
Effects are stronger on easy (low load) tasks and high capacity
Selection
singling out certain pieces of information among many
Selective Attention
The capacity to concentrate on the relevant characteristic of a stimulus
-ignoring irrelevant information
External Attention
attending outwardly to select and modulate sensory information from the world
-division between external and internal attention is not clear & they can influence each other
Internal Attention
selecting, modulating, and maintaining internally generated information
-division between external and internal attention is not clear & they can influence each other
Vogel et al. Study: Working Memory and Attention
The amount of information we can hold in our working memory may be linked to how well we direct external attention
-low working memory capacity: more activation when presented with distractor items
-high working memory capacity: more efficient external attention, less activation when presented with distractor items
eye tracking
cameras record where participant is looking
-we move our eyes a lot to piece together a high resolution picture due to highest acuity being in the fovea (center of eye)
saccades
rapid eye movement
-used to measure overt attention
overt attention
attention directed in an outwardly observable way
covert attention
directing attention in a way that could not be discerned by someone watching you
Multiple-object tracking
keeping track of several identical items that move among other identical items
-covertly
-typically able to track about four items
-ie. parents keeping track of children in crowd
Misdirection
Magicians direct your attention away from the place where the trick happens
based on:
-inattentional blindness
-change blindness
Inattentional blindness
failure to encode part of a sensory stimulus
-ie. missing the gorilla walk by in the video counting basketball passes
Change blindness
failure to notice change in an encoded object
-ie. frame of black in between changed in scene
-ie. fail to notice magician change shirt
Voluntary (endogenous) attention
Attention that requires effort to select and maintain focus on goal-relevant information
Reflexive (exogenous) attention
Attending to a particular stimulus because it has seized your attention instead of choosing to attend to it
Posner Cueing Task
Watching a screen at a fixation point and trying to respond to a target that will appear
Endogenous cue: Before the object appears, an arrow may point to the target location which engages voluntary attention
Exogenous cue: Before the object appears a red box may surround the target location which engages reflexive attention
Cues can be valid or invalid
Frontal Eye Field (FEF)
Part of endogenous (voluntary) attention network
-Directs gaze according to cognitive goals rather than characteristics of stimuli
Intraparietal sulcus and superior parietal lobe (IPS)
Part of endogenous (voluntary) attention network
-Crucial for maintenance of endogenous information
-Maintaining attention toward goals
Ventral Frontal Cortex (VFC)
Part of exogenous (reflexive) attention network
Analyzes novelty of stimuli over short periods of time
Temporoparietal junction
Part of exogenous (reflexive) attention network
Steers attention toward novel or unexpected stimuli
-directs input from visual cortex to ventral frontal cortex
Endogenous cue
Engages voluntary attention
Don’t have to move eyes away from fixation point
Exogenous cue
Engages reflective attention
Grabbing attention away from fixation point
Inhibition of return
short-lived supression of information processing at a just-attended location -aids our ability to find things as you avoid checking the same place over and over again
Spatial attention/Location-based attention
moving attention from one place to another
-like in posner cueing task
Object-based attention
Attention being directed to one place on an object
-attention to one part of the object entails attention to the whole object
Holistic Perception In object based attention
In an object based attention experiment invalid cues on the same side as the target had a quicker response to the target than invalid cues on a different side as the target
But there shouldn’t be a difference between these invalid cues
-This suggests Holistic perception is taking place as the whole object is being processed which allows to invalid cue on the same side as the target to result in a faster response to the target
Hemispatial neglect
No attention paid to the left side of the body or things presented to that side due to damage to the right side of the parietal lobe
Attentional Bias
Tendency to direct attention to some types of stimuli over others
Dot-probe Task
Participants try to respond quickly to a target (like a dot) that can appear at one of two locations
Location 1: a threatening stimulus was shown just prior to the target appearing
Location 2: a non-threatening stimulus was shown just prior to the target appearing
Found that anxious participants respond more quickly to the target at the location with the threatening stimulus suggesting attention had been drawn to that location due to the perceived threat.
Biased Competition
stimuli in a cluttered visual environment compete with eachother to drive the responses of neurons in the visual system
-each neuron tends to respond optimally to stimuli falling within a specific part of the visual field
-Each neuron has a receptive field that demonstrates a bias toward stimuli of interest
Top-down selection
Part of biased competition
Selection in favor of items that are goal related
Bottom-up selection
Part of biased competition
selection is driven by the salience of physical features
Receptive Field
Each neuron’s preferred region of the visual field
-biased toward stimulus of interest
Ambiguity Resolution theory of visual selective attention
Selective attention resolves ambiguity of possible mental representations of the external world created by multiple stimuli
-aspects of the environment (shape, color, size) are represented in the brain through broadly distributed clusters of neural activation
-a cluster of neurons can actively support several representations like an overlapping network of green fruit
-by selecting the object and placing attention this resolves ambiguity such as whether you are looking at a green apple or a pear
Dichotic Listening Paradigm
Attended and unattended stream playing in either ear
Attended stream is payed attention to
Different message is playing in unattended stream and participant is not asked to do anything with this message
Cocktail party problem
People’s ability to attend to one stream/channel of information while ignoring others
Early selection
when we attentionally select stimuli based on physical features such as color, pitch, or location; we register their meaning after selecting them
ie. if told to only pay attention to a women’s voice you would filter out information falling below a certain pitch and then register the meaning of the words after selecting the stimuli to attend to
Late selection
When we process the meaning of everything around us before selecting for heightened awareness
ie. you hear your name mentioned in a different conversation even though you weren’t attending to the other conversation
Preattentive processing
Extent to which we process information before attentionally selecting it
Cherry (1953) Dichotic Listening Paradigm Findings
Participants knew that there was a message in the unattended stream and could identify the pitch or gender of speaker
Participants could not identify what was said or if the language changed for example from English to German
Donald Broadbent’s Filter Model of Attention
Supports Early Selection
Attended and Unattended message inputs
These go into a sensory store that holds into information for a fraction of a second
This information goes to the selective filter which identifies the attended message based on physical characteristics - the unattended message is completely blocked
Just the attended message goes onto higher level processing
Neville Moray Dichotic Listening Paradigm - Early selection
Early selection
Attended stream playing a list of different names
Unattended stream playing a list of names that included the participant’s
1/3 of participants remembered hearing their name
Suggests that some information in the unattended stream is still accessible and not completely filtered - doesn’t comply with filter model of attention
-perhaps we have a personal dictionary
Dictionary Threshold
Some words have personal significance and we care about them a lot more - they exceed the “dictionary threshold” and grab our attention even when unattended
Other words don’t exceed the threshold and we’re unlikely to be aware of them in an unattended stream
Gray and Wedderburn Dichotic Listening Paradigm - Late Selection
Late selection
Attended stream: Dear, seven, Jane
Unattended: Nine, Auntie, Five
Participants incorrectly remember hearing “Dear Auntie Jane”
-People used information from the unattended stream to find meaning
Suggests some information in unattended stream is still accessible and not completely filtered out
Donald Mackay Dichotic Listening Paradigm - Late selection
Late selection
Attended: throwing stones at the bank
Unattended: water related words like river
Participants incorrectly identified sentences like “throwing stones in the river” when shown a list of sentences and asked to report what they heard
Treisman’s Attenuator Model - Late selection
Late Selection
Attentional selection initially occurs based on early, physical properties but does not eliminate processing of unattended information
Instead of being completely eliminated, the strength of the unattended signal is weakened, even as the attended information is fully processed.
Suggests why particularly meaningful stimuli (like one’s name) are perceived in unattended streams.
-meaningful information needs to reach a lower threshold of processing in order to reach awareness
Attended + unattended stream = sensory and language buffer for physical characteristic selection = dictionary that makes sense of words and whats important = Attenuator that selectively attenuates to unattended streams if relevant to task = higher processing
Feature-Based Attention
Ability to attend to or filter out information based on features like color, shape, or motion; tuning attention to certain features
Looking for a particular feature increases activity in neural regions sensitive to the target feature across the visual field, even without sensory stimulation
When people tune their attention for specific features, those features are more likely to reach awareness
Visual Search Task
Participants look for a target embedded in embedded in an array of non targets
Single features of stimuli are parsed easily in isolation - ie. a white square among black circles : parallel processing
Multiple features require binding of features into one salient object - ie. a white square among white circles and black squares : serial processing
Parallel Processing
Taking stimuli in all at once
In visual search task: a white square among black circles
-Search time remains consistent regardless of number of items in the display because we don’t have to search through targets one by one
Serial Processing
Taking in items one at a time
In visual search task: white square among white circles and black squares
-Search time increases as the number of items in the display increases because we have to search through items one by one
Feature Integration Theory
During preattentive processing (processing information before it’s attentionally selected) we experience the world as a jumble of simple features that are not bound together into cohesive objects
Focusing attention on an object binds these features together (color, shape, motion), which allows us to perceive a meaningful object
Findings are consistent with the idea that although we can process features prior to attentional selection we need attention to combine them accurately
Binding Problem (feature integration theory)
The challenge of figuring out which visual features in the environment combine together to form cohesive perceptions of objects
Illusory Conjunctions (Feature integration theory)
The incorrect combining of features that are not actually combined
ie. presented a red A and a blue X, people are likely to report a blue A, and a red X.
Support for feature integration theory: although we are able to process features prior to attentional selection, we need attention to combine them accurately
Load theory
Attentional selection depends on how demanding the attended task is
-Unattended information or distractors can take attentional resources, be analyzed more, reach awareness, and interfere with the task at hand in a low load task
-Unattended information or distractors is filtered out early with a high load task
Temporal Attention
Ability to pay attention to points in time
-Rapid serial visual presentation task: participants try to find two targets in a very rapid sequence of items-they have difficulty reporting the second target if it appears too soon after the first target
Attentional Blink
When the second of two targets in rapid succession of items is more difficult to detect than the first
Explicit Attention
Attention resulting in conscious awareness
-measures usually rely on conscious report
Implicit Attention
Attention that does not lead to conscious awareness
-measured via response time, eye movement, etc.
Blindsight
a condition in which patients who have suffered damage to their visual cortex (e.g., through stroke) are sometimes able to respond to and localize visual stimuli that they report not being able to see
-demonstrates implicit attention
Emotion Induced Blindness
The failure to see rapidly presented targets that appear right after a rapidly presented emotional non target
-With strong emotional content we’re more likely to focus on specific details of the emotional content
-Like in a robbery- we don’t pay attention to the robbers face we pay attention to the gun
Attentional capture
Involuntary (reflexive) grabbing of attention by certain kinds of stimuli
Saliency map: the visual system computes differences between signals across the visual field and forms a topographical representation ;across a field of view, areas with sharp visual contrast (ie. a yellow dandelion in a green lawn) are salient and draw attention
-aspects computed to have high salience capture attention automatically
Continuous performance task
Tests attentional vigilance
-Required to stay on task for a prolonged period of time
-Real world implications such as for TSA agents who have to remain vigilant for prolonged periods
-Findings have discovered people are poor at detecting objects that appear rarely
