lecture 3 Flashcards
define attention
is the process by which the mind chooses from among the various stimuli that strike the sense at any moment.
define divided attention
we can focus on one conversation and block another one. e.g. the cocktail party phenomenon.
what is the early selection model?
early in the processing stream that attention acts.
late selection model
attention happens at the later stages e.g. attention sets in when we identify.
we can attend to a stimulus if it has high…
valience
how are cats an example of early selection model of attention?
- measure brain stem of cats whilst sounds were played, 3 different conditions. they played a sound and it was found that the neuron inflection was smaller than usual when the cat was staring at the mouse
what other explanation could exaplin why their was a smaller inflection in the mouse condition?
the inflection could be that was smaller because the ears were pointing down in the mouse condition
what is dichotic listening?
hearing two different messages in each ear.
electrophysiological measures
results of the ERP for dichotic listening?
record signal for both ignored and attended message. There was a higher input for the ignored- suggest evidence for early selection
MEG is used to reconstruct…
to pin point the location, so we can say that attention occurs for early selection as the brain area is lighten up.
exogneous attention
transient, bottom-up, or automatic e.g. environmental triggers such as a loud bang.
endogenous attention
sustaine, top down or voluntary- what we choose to pay attention to.
valid and invalid cue trials
- we react raster when we see what we expect to see
- posner matching task
ERP evidence
what results from ERP support the endogenous task
when you attend to the left where we expect the target to be there is a larger inflection in the neuron signals
what is the inhibition fo return
time gap between cues is too long, reaction times increase when dots appear before the box but this doesnt happen if box happen if the box appeas more than 250 milliseconds after the box- interstimuli interval
spatial attention
attention to a specific location in space irrespective of what else is present
feature based attention
attention to specific stimulus features irrespective of their environment
object based attention
attention to specific parts of the object
neurons fire more when the stimulus…
receptive field is attended to- this firing leads to the EEG and ERP effect.
what is a retinotopic visual area on a flattened brain means…
use clever stimuli to mao out areas, a mirror image of the outside world is represented int he brain.
what is retinotopy
the orderly representation of the retinal image of the brain.
what is the biased competition model of attention
if both stimuli are presented simultaenously there is an immediate response
you can win the competition of attention by…
being the stimulus the animal attends to.
recpetive fields tend to…
shrink when we attend to a specific stimuli
dorsal pathway
motion
ventral pathway
colour and objects.
evidence for dorsal and ventral pathways
the dots move and change colour, so they found that when asked to attend to motion MT is active and when you tend to colour v4 is active.
object attention
i
is an automatic spreading of information across the object.
How do you measure spatial and feature attention?
Pop out search and conjunction search- pop out is more easily spotted as conjunction is a combination of features
What is the RT for pop out and conjunction
Pop out stay consistent, set size increases for conjunction search to reaction time also increases.
