Wk2 - Selective Attention Flashcards
key aspects of attention 5
selectivity
capacity limitation
vigiliance ('sustained attention')
perceptual set ('expectation')
switchingsome ways attention can be selective 3
spatial, temporal, motoric (action)
theoretically why is there a capacity limitation in attention?
the motor system requires ‘one winner’ and only does one thing at a time
how predictive were the cues in the Posner task?
80%
what ‘cost’ was incurred in the posner task?
reaction times were slower for invalid cues
describe contingent capture effect
what result would define this?
attentional capture is dependent on the feature match between the cue and the target.
invalid cues don’t slow responses when the target doesn’t match the cue (i.e. attention is only captured by cues that match the target)
what type of visual search is not affected by the amount of elements in a display?
feature (pop-out) search
what explains why search slopes are larger for target absent displays?
on average more items need to be search to confirm target absence
the ‘what’ pathway of the visual systems extends to which region?
inferotemporal cortex
parietal cortex processes what general type of information?
how/action-based
what are 2 aspects of primate visual system organisation?
modular regions
hierarchical connections
how do visual receptive fields differ by region? 2
size increases up the hierarchy: more immediate regions (V1) have smaller RFs than later regions (V4)
increasingly complex prefered stimuli
V4 neurons are receptive to
colour
describe the effect of feature selective attention that has been in primate v4
colour responsive neurons are more active when the receptive field is passed over a goal-relevant colour, compared to passing over the colour when it is not goal-relevant
what ERP marker of attention is observed in a dichotic listening task?
N1
what ERP marker of attention is observed during spatial attention and how is it characterised?
increased P1 for the attended visual stimuli, which is observed over the contralateral occipital region
what does fMRI reveal about automatic capture of spatial attention?
it modulates the bold response more for higher level visual areas (from V1 up to hV4)
how does voluntary spatial attention modulate BOLD signals in V1, when detecting the presence of a patter?
the anticipation of the pattern occuring increasing the V1 bold response and is only slightly increased when the pattern is actually present.
this shows the visual processing is modulated largely endogenously
what is the neural effect of TMS?
neurons are depolarised, making them fire
3 things TMS can do to the brain
suppress/enhance perception, elicit phosphenes, alter cortical excitability
what is the human homologue of the primate LIP?
angular gyrus (parietal lobe)
what was varied in the study of automatic spatial attention using TMS?
what was the focal question and corresponding conditions to examine this?
TMS pulse was delivered at one of 12 times, post-target onset (task was to discriminate the spatial frequency at a cued/uncued location)
when TMS disrupts the shifting of automatic spatial attention.
invalidly cued trials that require people to shift away from the cued locations
what does TMS over the right angular gyrus reveal during a spatial cueing task?
two time points of applied TMS reduce performance at invalidly cued locations, suggesting two distinct pathways for shifting attention
name two pathways involved in automatic attention shifts
(fast) retinotectal pathway
(slow) geniculostriate
what was the task in Rees et al. (1999) fMRI study of inattentional blindness?
the findings?
attend to a stream of either object or overlayed words and detect when a stimulus was repeated
BOLD response is greater in regions processing the corresponding modality (language area vs object area)
why does change blindness occur?
local transients are normally what draw attention to location of changes. mask between changes disrupts these local transients
what brain area prominently activates when change is detected vs undetected in task-irrelevant faces?
right parietal lobe
