5 - Attention and Perception Flashcards
define attention
selecting sensory inputs, increasing their importance by focusing on them, and processing them further
define selective attention
mechanism to focus mental processing on a limited number of events/stimuli
define spatial attention
mechanism to focus on a particular position in space
what did James describe attention as
taking possession of the mind in vivid forms one out of what seems several simultaneous possible objects or thought streams
what is selective attention
focusing, filtering, awareness
difference between overt and covert attention
attention and gaze direction are different in covert but same in overt
define shifting attention
going from focusing on and processing one stimuli to another
what is focusing
enabling detailed processing of important sensory inputs
what is awareness
paying attention to what we’re conscious of
what is dichotic listening
one ear’s input channel is attended and the other is unattended
what’s shadowing
repeating what’s said
is information spoken in the unattended channel noticed
no but can report physical attributes like speaker’s gender and words with personal importance catch attention
define filter
nervous system inhibiting certain responses so distractor info isn’t let through but promotes processing of desired info
what’s exogenous selection and how is it tested
attention shifting to loud, bright, sudden stimuli
how do cueing paradigms work
fixation point in middle of screen, cue appears reflecting likely stimulus appearance
results from exogenous selectionb
valid had faster response than neutral and invalid, so eyes don’t need to move for attention shift
in exogenous cuing which neurons fire
ones corresponding to space where attentional cue is
define endogenous selection
controlled by own intentions and interest, guided by internal voluntary processes
what happens when thes stimulus is made more salient in endogenous selection
importance of it increases so more aware of that sensory info than others
how does paying attention to whole objects work
superimposed stimulus on top of others
focus on one object despite many being in same space
how does spatial selection work
directing attention to particular location enhances responses in corresponding neurons
how does attention to features work
we look for things w a combination of features
what is a parallel search
single feature difference can be distracting so target is easy to find
reaction time is the same regardless of # of distractors
what is a serial search
more feature differences/distractors make it harder to find the target
why is the reaction time longer in a serial search with more distractors
need to allocate more attention resources to distractors
define info bottleneck
channel of information processing has limited capacity and data volume is too much
describe the response selection model
selection occurs late in processing but before the response occurs
in the response selection mode, what happens after all signals get through
not all consciously experienced and unattended signals get through and processed late in information evaluation
describe the perceptual load model
task difficulty determines if selection is early or late and attention is selective when capacity is full
in the perceptual load model, when can the brain process information outside of attention
when we have spare capacity
in the perceptual load mode, when does late selection occur
if tasks have a light cog load
why do complex tasks have early selection, as stated in the perceptual load model
it shows us the difficulty of the task
describe the study which shows that a low load task had a stronger signal than a high load due to higher processing (perceptual load model)
moving dots in background to see V5 activity which deals w motion in 2 conditions: high and low effort when words presented
what is the spotlight metaphor and what type of attention does it refer to
spatial area being prepared and moved around
sustained visual attention, NOT eye movement
with spotlights, what do we focus on and why
visually prominent, interesting, important things
based on context, beliefs about the scene, expectations
define consciousness
interface between mental processes and world’s sequential demands to prevent us being overwhelmed and track unconscious processes
define inattentional blindness
a usually obvious stimulus occurring when attention is distracted and not selected it as important, so don’t ‘see’ it even when looking at it
why does inattentional blindness occur
eyes see the obvious event but attention hasn’t so experience but don’t remember the change
define change blindness
when a change occurs in the environment we’re looking at but remainds unseen
define early selection
attended info selected and processed from the start, unattended info barely analysed
what has been found out about the brain in terms of early selection
electrical activity distinguishable between un/attended info after stimulus presented
lateral geniculate nucleus activity affected
what’s been found about nervous system activity in early selection
attention changes signals within the nervous system before they reach the brain
what is late selection
selection occurs after all input info is analysed
in late selection, can distractors still be perceived
yes
in late selection, when does selection occur
either before stimuli reach consciousness or after but only selected are remembered
define priming
preparing self for perception by activating detectors we believe we’ll need to perceive the stimulus
how does priming explain inattentional blindness
stimulus falls on unprimed detectors which don’t fire so goes unnoticed
how does priming allow selective listening
unattended output ignored so detectors are unprimed and there’s no perception
define repetition priming
no resources needed for priming as activation level is high as already primed since we encounter the stimulus often
how does priming explain the cocktail party effect
detectors primed to fire when stimulus encountered often occurs even in unattended channels
define expectation-driven priming
deliberately priming detectors for expected stimulus only when prime allows prediction of what’s coming
how does expectation-driven priming explain there being no difference between invalid and neutral cues in the exogenous cuing paradigm
priming wrong detector takes nothing away from needed detectors which so they’re the same
the valid cues produced what compared to invalid cues
warm up effect and expectation effect compared to just warm-up
what is a limited capacity system in priming
priming the wrong detector takes away from others so less prepared for other targets
which brain pathways are involved
dorsal (spatial, where)
ventral (non-spatial, what)
modulation by attention affects processing where
early visual cortex, V5, left frontal language regions, fusiform face area
where does modulation come from
right parietal cortex
where does spatial selection occur in the brain
retinotopic maps in EVC
what cortex is responsible for sustained attention
right frontal cortex
keychain for orienting system
frontal/parietal cortices, superior colliculus listens, thalamus pays attention
brain areas responsible for the control system
visual areas in occipital cortex analyse incoming info, control signals amplify/inhibit signals to promote/inhibit processing
define unilateral visual neglect
failing to attend to or notice stimuli on side contralateral to hemisphere with lesion due to dorsal pathway and RP lobe damage
in unilateral visual neglect, what is there a failure to do
disengage attention from the target in the field contralateral to the unaffected hemisphere
what type of task is used to study unilateral visual neglect and why
line bisection as shows patients unconsciously aware of total line length through bisection
what do line bisection tasks show about awareness
neglected side unconsciously processes but conscious awareness can’t reach this
why is UVN not blindness
no visual cortex lesions and light can be detected on contralesional side
what does the barbell study show
when red circle in unaffected visual field then rotated so it’s on contralesional left side, attention still paid
what does the barbell study mean about the type of attention affected in UVN
target defines attention focus so object not spatially based
define object-based neglect
inability to process contralesional side of individual objects
what is Balint’s syndrome
inability to shift visual attention to new locations due to damage to both brain sides so can’t focus on objects outside spotlight even if looking at them
what is blindsight
residual vision in absence of cortical processing so consciously unaware of what’s seen and can detect but not describe stimuli
