Week 8: Object-Based Attention and Cogitive Neuropsychology of attention Flashcards
What does attention Act Upon? (2)
Spotlight theory, assume attention acts on a region of space – enhances processing in that region
Alternative: attention acts on objects in space, not space itself: object based theories
object based theories:
Study 1
Rock and Gutman (1981)
Description (S3)
Overlapping figures (abstract)
Participants attend to one and rate aesthetic appeal; ignore other
Then given memory test:
Either on the red or green shapes without the colour, then asked did you study tt
object based theories:
Study 1
Rock and Gutman (1981)
Results (S3)
Good mem for attended figure (cf. Cherry, 1953 -> audio)
Objects occupy same region of space (unlike left right ear)
=> contradict the spotlight of attention, maybe pay attention for object, not space.
What happens to the Unattended Shape in Rock and Gutman (1981)?
Tipper (1985, etc.)
Maybe it’s not perceived or not fully perceived?
Maybe people quickly forget the stimulus they’re not attending to? – inattentional amnesia
(cf. early vs. late selection)
What happens to the Unattended Shape in Rock and Gutman (1981)?
Tipper (1985, etc.)
Negative priming
Pairs of red-green figures: trumpet-kite, anchor-trumpet etc (similar to Rock and Gutman just non-abstract figures)
Ignore green name red (e.g., ignore trumpet name kite)
What happens when trumpet must be named?:
RT to name trumpet is slower if ignored on previous trial
=>“Negative priming” (regular priming produces speed up)
Means ignored shape must have been perceived (recognised and cognitively registered to be ignored) to produce effect on subsequent trial (cf. late selection)
Maybe operating on object, not space
Implications of Rock & Guttman, Negative Priming
Possible to attend to one object and ignore another when both occupy same region of space
Maybe attention operates on the object, not the space
Evidence for Object-Based Attention
Duncan (1984) (s7)
Description
stimuli differing on four attributes: box size (big/small), gap side(right/left), line slant(right/left), style of the line(dotted/dashed)
Flash briefly, ask to report two of the attributes (e.g., line slant, gap side)
two groups:
1) Report 2 from same object (box/line)
2) Report 1 from each object
Evidence for Object-Based Attention
Duncan (1984)
Results
More accurate if the two attributes belonged to same object than different objects
Existence of benefit if belong to same object.
Stimuli occupy same region of space
Evidence that attention operates on the perceptual object, not the space.
Cuing Object-Based Attention
(Egly, Driver, & Rafal, 1994)
(S9)
Description and results
Conditions:
1) cued
2) Miscued same object
3) Miscued different object
the predictions:
Space Theory:
Faster for condition (1). the others would be similar as only space matter.
Object theory:
1) Faster for condition 1 and 2 as they belong to the same object compared to 3.
Cuing Object-Based Attention
(Egly, Driver, & Rafal, 1994)
(S10)
Results
Same object advantage: Mean RTs faster to miscued stimuli if in same object
Evidence that cuing effect spreads to encompass cued objects
Cuing Object-Based Attention with …
Effects of an Occluding Bar (Moore, Yantis, & Vaughan, 1998)
Description and results
Same as (Egly, Driver, & Rafal, 1994) with an Occluding Bar across the the 2 objects
Occluding bar in stereo space: still find same object advantage
Not related to crossing edges or boundaries; agrees with percept of continuous objects.
Neuroimaging Evidence For Object-Based Attention
Selective fMRI activation when viewing houses and faces
Fusiform face area – active when viewing faces
Parahippocampal place area – active when viewing houses
Superimpose: attend to face or house
Viewing Face: FFA up, PPA down;
Viewing House: PPA up, FFA down
Evidence that attention selects objects in space
possibly by enhancing representation of selected object; suppression of other object
Attention to part of an object benefits other parts
Neuropsychology of Attention:
Visual Neglect
Control of attention involves balance of top-down and bottom-up systems
Reflexive system orients to new stimuli, voluntary system provides sustained attentional focus
Failure to focus and failure to disengage and reorient both found in clinical cases
Damage to right parietal lobe -> deficits is lateralised
Attention and Visual Pathways
2 main streams (in the brain)
1) Ventral pathway, temporal lobe: form, colour – what pathway
2) Dorsal pathway, parietal lobe: direction of motion, spatial location – where pathway
Parietal lobe damage disrupts “where” pathway