Chapter 4 - External Attention Flashcards
Attention
cognitive mechanisms that combine to help us select, modulate, and sustain focus on information that might be most relevant for behavior
capacity-limited: we can only handle small amounts of information at a time
External vs Internal Attention
external attention: where we attend outwardly to select and modulate sensory information
internal attention: where we select, modulate, and maintain internally generated information (e.g. thoughts, memories)
not a clear division between the two, and they can influence each other
Overt vs Covert Attention
overt attention: moving your eyes to object/location of interest
causes object to fall on fovea of eye
can measure overt attention with eye-trackers
covert attention: moving attention to independent of where eyes are pointed
saccades (eye movements) to a location - preceded by covert attention
use covert attention when tracking multiple objects
Selective Attention
ability to focus on one source of information while ignoring all others
Attentional Selection
attentional selection is controlled by:
voluntary attention (endogenous): controlled by goals of individual, top-down
reflexive attention (exogenous): attention controlled by environment, bottom-up
salient information “captures” attention
Spatial Attention
Posner (1980) likened attention to a spotlight where you select regions of space for special processing
Posner - Spatial Cuing Experiment
question: does attention influence time needed to detect a stimulus there?
cue: indicates where a subsequent target may be
valid (correct location)
invalid (incorrect location)
neutral (uninformative)
stimulus onset asynchrony (SOA): the time between the onset of cue and onset of target
Selection in Space - Peripheral and Symbolic Cues
peripheral cues: exogenous shifts of attention
stimulus-driven
automatic and faster
symbolic cues: endogenous shifts of attention
goal-driven
volitional and slower
Inhibition of Return
once attention visits a location and then shifts away, location is being “inhibited”
Feature-Based Attention
can tune attention to select a specific feature (color, motion, orientation)
neurons responsive to that feature
- enhanced response
neurons tuned to other features
- suppressed response
Neglect Syndrome
damage to parietal lobe
ignore 1/2 of visual field (space-based)
ignore 1/2 of objects (object-based)
contralesional deficits: right hemisphere damage and the left is neglect, behave as if neglected objects are not present
Corbetta & Shulman (2002)
proposed two different attentional networks:
ventrial attention network:
bottom-up attentional control
salient events in environment
exogeneous attentional control
dorsal attention network:
top-down attentional control
goals influence attention
endogenous attentional control
Corbetta & Shulman - Theory of Neglect (2002)
patients have damage to stimulus-driven (exogenous) attentional system
many neglect patients have damage to right temporo-parietal junction
normal: objects competing with one another for attention (exogenously)
neglect: objects in neglected field can’t compete for attention
Biased Competiton Theory
too much information at any one time
information “competes” for neural control/awareness
stimuli in a cluttered visual environment compete to control the responses of neurons in the visual system
selective attention biases the competition in favor of one stimulus over the other
Visual Search
looking for a target in a display containing distractors (e.g. looking for hairbrush on a crowded vanity, looking for a friend at a party)
laboratory search tasks: reaction time to find target plotted as a function of set size (number of distractors)
examine reaction time to find target as function of set size (number of items on display)
feature searches: target defined by single feature, done in parallel with unlimited capacity, reaction time does not increase
conjunction searches: target defined by combo of features, done in serial, reaction time increases with set size
Feature Integration Theory (FIT)
Treisman and Gelade (1980)
proposed two different processing stages
preattentive stage
attentive stage
Preattentive Stage vs Attentive Stage
preattentive stage: automatic, no effort required
unaware of processing, parallel processing
object analyzed into features
attentive stage: features are combined into object recongition
“binding” of features to object representation, requires focused attention, attention moves serially from item to item
FIT and Illusory Conjunctions
Treisman and Schimdt (1982)
primary task: report two black digits
secondary task: describe objects present
participants report combination of features from different stimuli
illusory conjunctions occur because features are “free flowing”
Dichotic Listening
1950’s-1960’s - research looking into auditory attention, often used dichotic listening task
one message is presented to the left ear and another to the right
participant “shadows” one message to ensure they are attending to that message
Results of Dichotic Listening
participants cannot report the content of the message in unattended ear, failed to notice change in content and language
however, unattended ear is being processed at some level, change from speech to another sound is noticed
Broadbent’s (1958) Filter of Selective Attention Theory
multiple inputs from senses, inputs stored briefly in a sensory store
filter controlled what inputs were further processed (all other inputs blocked), filter could select information based on physical characteristics
meaning wasn’t extracted until information passed through Limited Capacity Channel
Treisman’s Attenuation Theory
messages enter Attenuator
analyzes incoming messages in terms of physical characteristics, language, and meaning, messages being attended is let through the attenuator at full strength
messages then enter Dictionary Unit
contains words we know, each with different thresholds for being activated
words that are common or important have low thresholds, uncommon words have high thresholds
activated words enter memory (awareness)
Deutsch & Deutsch’s Late Selection Model
selection of stimuli for final processing does not occur until after information has been analyzed for meaning
Load Theory - Perceptual Load
Lavie & Cox (1997)
subjects performed a search task
ignore flanking letter on outside of ring
low load (easy search) - target pops out, flanker interferes
high load (hard search) - target requires search, attentional resources being used to find target, flanker doesn’t interfere
Load Theory - Working Memory Load
working memory load - more irrelevant information processed, tested memory load
results: high memory load had harder time ignoring faces
low memory load had easier time ignoring faces
Inattentional Blindness
failure to notice an unexpected item in front of eyes when attention is preoccupied
Change Blindness
failure to notice large changes from one view to the next
Most & Astur (2007) - Inattentional Blindness and Driving
subjects in driving simulator
follow blue or yellow arrows at intersection and ignore other colored arrows
at intersection, motorcycle swerves in front that either matched or mismatched arrows
results: slower to brake and more likely to hit motorcycle that does not match arrows
Temporal Attention
attending to information in time
Attentional Control
top-down (endogenous control): attention to locations/objects that help accomplish current goals
bottom-down(exogenous control): salient objects will attract attention
attention might be directed to emotional/dangerous stimuli, might be influenced by anxiety/phobias
Attentional Blink
subjects have difficulty reporting the second target if it appears too soon after the first target
attention needs a “resetting period” before a second item can be brought to conscious awareness
Attentional Control - Dot Probe Task
Bradely et. al (1999)
tested patients with Generalized Anxiety Disorder (GAD)
pictures of emotional/neutral face replaced by dot
GAD subjects biased towards anger
Emotional State
mood may influence attentional scope
Broaden-and-Build Theory: when safe/happy - can expand and take in new experiences
when threatened/anxious - need to keep focus on most relevant things
Fredrickson and Brannigan (2005)
subjects watched video clips meant to induce positive or negative emotions
test on local vs. global attention bias
positive mood = choose more “global” matches
negative mood = choose more “local” matches
