Lecture 5 Attention Flashcards
Duncan 1984
Showed participants a stimuli with 2 objects, box and broken line, superimposed, which could differ in attributes :box size, gap side, line slant, dotted or dashed line.
Before showing, they were told which attributes to focus on.
People were more accurate when asked 2 attributes which were on ONE of the objects, rather than on the box AND the line.
People lost accuracy when had to form representations of 2 objects - object based attention
What was found when people were shown superimposed images and were negatively primed?
They did in fact perceive the ignored object, as they look longer to name them, than the attended object
Rock and Gutman
What was found when people were shown a line and a box in the space space and asked to name attributes about them?
People were more accurate if the two attributes asked were in the same space - people lost accuracy if they had to represent both objects rather than one
Object based attention
Duncan 1984
Egly, driver, Rafal
Used 2 long rectangles, where then stimulus could pop up on either end of the 2 objects, making 4 possible options, and 4 cue areas
Could miscue 2 diff ways - within the same object, or in the other object
When the stimulus is a presented in the UNCUED OBJECT, RT is SLOWER
Same object advantage is apparently
Object based attention effect
Effects of an occlude get bar?
Moore, yantis and Vaughan
The including bar obstructs the image, but still find object advantage.
Attention and RT time was not related to crossing edges or boundaries. We perceive continuous objects
3D perceptual effect.
Neuroimaging evidence for object based attention?
Selective fmri activation when viewing houses and faces
Faces - fusiform face area
Houses - parahippocampal place area
When you superimpose a face and house, and ask person to only focus on one, then more activation will go to one of those areas and less for the other
What does visual neglect arise from?
Damage to right parietal lobe
Deficit in processing spatial info
Difficulty in making left side of space accessible to conscious awareness.
What attention does reflective and voluntary systems provide?
Reflexive - new stimuli
Voluntary - sustained attentional focus
What are the two pathways of processing visual info?
Ventral pathway and dorsal pathway
What does the ventral pathway of processing visual info do
It is in the temporal lobe
Processes form and colour - WHAT pathway
What does dorsal pathway in visual info processing do
Parietal lobe
Direction of motion, spatial location
WHERE pathway
Spatial neglect people have this damaged
Rock and Gutman?
Used abstract overlapping features.
Told subjects to rate aesthetic appeal of one.
Surprise memory test, and they had no memory of the object they didn’t attend even though it was occupying the same space - object based attention
Doesn’t fit spatial theories - spotlight theory and FIT
Then, used name able objects superimposed. NEGATVELY PRIMED some objects, and found that ignored objects took longer to name by memory.
Means that the ignored object WAS perceived
What are the cuing deficits of right parietal damage?
RT got heaps longer when the invalid cue was in the right side and the stimuli was on the LEFT.
Ability to voluntarily engage attention was not impaired, but disengaging and shifting response was impaired
What happened with neglect people who were shown two everyday objects
They were good when you showed them one object which was in the left
But if you placed a second object in the right visual field, then there was a large left visual field deficit.
Exctinciton occurred.
Kinda agrees with late selection that only one thing can get through filter at a time
What is balint’s syndrome
Bilateral lesions in parietal and or occipital lobe
Can’t see more than a single fixated object.
Ocular ataxia - can’t shift fixation from one object to another
Simultanagnosia - can’t see more than one object at a time
Occurs even when things overlap
Object based :-)
