lecture 6 - Attention as spotlight

Question 1

Posner’s spotlight model
-what did he develop
-what else did he study

Answer 1

Michael I. Posner (1936-)
(Emeritus Professor at
University of Oregon)

• Mainly known for developing
  the “Posner Cueing Paradigm”
  to study attention
• Also did pioneering studies in
  attentional development in
  children, and in using PET to
  localize brain function

Question 2

posner et al 1980
endogenous cueing paradigm,

Answer 2

-you fixate on a cross and eventually a number comes up, and it tells you which of the 4 lights will most likely light up.

-you should feel your attentional spotlight shift to the light your expecting it to

Question 3

results of posner cueing paradigm

Answer 3

When the target appears
where you expect it to, you’re
faster to detect it.

• This is specific to location.
  Expecting a particular letter instead of a light then it does not make you faster to detect that letter.
• “These findings are consonant
  with the idea of attention as
  an internal eye or spotlight.

Question 4

exogenous cueing (combined)

Answer 4

-it’s physical properties will naturally draw your attention
-example : 2 boxes, if you brighten one box your attention will go to that box (your exogenously drawn to it)
-and then if the target appears in that box, you’ll be faster to detect it than if it appears in the opposite box, and then you have to redirect your attention all the way over to the target before you can respond to it

the demo in class where she used a volunteer
-it is an exogenous cue but has an endogenous component

Question 5

cues can be _____ or ______.
-what is the effect of a combined cue ?
-what range of cues can be used

Answer 5

Cues can be endogenous, or exogenous, or both.
-Combined endo/exo cues have the most powerful effect on detection RT

• Can use a range of different cue types: arrows, numbers, peripheral signals, auditory signals, faces
  looking left or right

Question 6

what tasks can we use in cueing
-do the results change?

Answer 6

Can use a range of different tasks: detection, discrimination, localization, eye movements,
pointing…

• Results tend to be largely the same: faster responses
  at the cued location, slower at the uncued

Question 7

cue validity
-what does this depend on

Answer 7

can modify
-the probability that the target will be in the same place as the cue

• 75%: cue predicts the target location – strong cueing effects (the demo was done with 75% cue)
• 50% un-informative cue – purely “reflexive” cueing effects*
• 25% counter-cueing – reversed cueing effects (spot dark, cue indicating where the target is less likely to appear)

Question 8

cue-target interval
what does it allow us to measure?

Answer 8

AKA cue-target “Stimulus Onset
Asynchrony” (SOA)
-the time between when the cue comes on and the target comes on

• Allows you to measure the time course of the effect of the cue.
  (when the cue comes on is there a perfect time for the target to to follow?)
• Do cueing effects get larger over time? Smaller?
• Depends on the type of cueing

Question 9

does the cue ‘illuminate’ / changes your perception of target or just speed up responses
Carrasco, M. & Barbot, A. (2018)

Answer 9

-manipulated perceptual features of the target
Spatial cues:
* Enhance contrast
* Distort object size
* Saturate colour
* Accelerate motion
* Increase duration
* (among other things!)

example of enhancing contrast:
-if you have a cued location and then have a patch appear and you have to compare it to a standard, so is it a higher or lower contrast than standard
-if the test patch is cued for it to be equal in contrast to the standard it can be a lower contrast (as if the cue itself has enhanced the contrast) - the lower contrast appears to be equal to the test
-if you cue the standard itself, then for the test to look equal, it has to be higher in contrast, because the standard now appears to be higher

-the cue itself has enhanced the perceived contrast of the thing that follows it

Question 10

how far can we take the metaphor
CAVE AND BICHOT, 1999

Answer 10

-unlike the filter and glue model, the spotlight is more of a metaphor (generates question)

paper goes over questions about how much is it like a spotlight (how far can we take it)

-Does it “slide”? No. It jumps.
* Does it “focus”? There can be larger and smaller attended regions and there is evidence it is “brighter” when more tightly focused.
* Is it “brighter” in the middle than at the edges? There is a gradient of attention but this is flexible, see above.
* There’s also a “spot dark”: Regions can be selected for suppression as well as enhancement.
* Can you “split the beam”? Usually, no.

Question 11

what /where is the spotlight

Answer 11

part of the brain in parietal lobe (lateral inter parietal area) seems to be essential for the focused spatial attention
but
Neurophysiological evidence that spatial cues enhance neural responses-
(e.g. in V4, Luck et al, 1997)

• Enhancement matches the time course of reaction time effects (Bisley and Goldberg, 2003)
• There is a “priority map” in the parietal lobe – peaks of higher activity for prioritised locations (e.g. Bisley & Goldberg, 2010)
  -peaks of activity associated with the with the locations your attending to right now
• Priorities can be driven by endogenous and exogenous factors

Question 12

current opinion of the spotlight

Answer 12

• Cueing effects are a robust and versatile behavioural marker of spatial shifts of attention
• Important observations about attention have been inspired by the spotlight framework
• It is more of a metaphor than a model (and there’s an obvious homunculus problem with the metaphor).
• There are many features and types of attention to which the spotlight metaphor is not easily applied.