attention

Question 1

what is the attentional blink?

Answer 1

attentional blink = ~0.5 second gap in attention when focus is changed

second of two targets cannot be detected or identified when it appears close in time to the first

when first item is being processed (500ms), second item cannot enter consolidation phase

Question 2

T or F

attention works at the same speed for valid and invalid cues

Answer 2

false

valid cue = attention cued to site and target is shown at this site

invalid cue = attention cued to site but target is shown at different site

attention much faster for valid cues

Question 3

how do neurons respond to cues at different orientations?

Answer 3

different neurons are excited/inhibited by different orientations

Question 4

how do we know where to direct attention?

Answer 4

frontal and parietal regions provide this top-down influence on the early sensory areas in the dorsal attention stream

this highlights where attention should be directed

Question 5

how is retinotopic activity effected by spatial attention?

Answer 5

spatial attention increases retinotopic activity in the attended location and selectivity of early sensory neurons

Question 6

what are the following areas responsible for in attention:

1) V4
2) MT
3) IT
4) LIP

Answer 6

V4 = form processing
MT = motion processing
IT = object selective info
LIP = high level association area

Question 7

what is the functional difference between the dorsal and ventral visual attentional networks?

Answer 7

node of dorsal attentional network = interparietal sulcus (IPS)
IPS is a task based cue network (i.e. it is told what to attend to)

node of ventral attentional network = temproparietal junction (TPJ)
TPJ responds to target and validity of cue, responds to surprising stimuli

Question 8

what is unilateral spatial neglect?

Answer 8

unilateral spatial neglect is a clinical disorder post-stroke where one is unable to attend to things in left side of space

caused by damage to ventral or dorsal streams

errors increase in close proximity (e.g. bisection error when told to draw point at centre of line)

lesion of right cortex = patients cannot focus their attention to the left side of perceptual space with changes to dorsal visual stream activity

Question 9

how does neuron selectivity change in response to strengthening stimulus?

Answer 9

when stimuli becomes stronger, neuron selectivity becomes much sharper and the overlap between the response of different neurons decreases

also thought that when stimuli increases, there may be an imbalance in activity of neurons to decrease overlap