Perception and High Level Vision Flashcards
Modularity Hypothesis states…
Activity of multiple cog. processors or modules
MH- Uniformity=?
All humans have same cog. architecture (so we can generalise)
MH- Subtractivity=?
Brain damage impairs modules but doesn’t change anything
MH- Isomorphism=?
Some correspondence between the mind and the brain
V1 (primary visual cortex) receives input from the…
Lateral Geniculate Nucleus (LGN)- first processing area of cortex
Blindsight may be caused by…
Damage to occipital lobe (V1)- cannot see in parts of their visual field
Riddoch (1917) found…
some processing does take place in the blind spots
Poppel, Held and Frost (1973) found…
Patients with blind spots looked towards the flash that they should not have been able to see
Unilateral Visual Neglect (hemispatial neglect, hemiagnosia, spatial neglect etc.)
Usually on right side (affects left vision) after right cerebral injury
Anosognosia
Person is not aware of their disablility
Bisiach found when asking patients to imagine the cathedral…
Patients with left neglect dont report seeing building on the left (neglect is found on a mental image too
Unilateral visual neglect occurs from…
damage to the internal spatial framework, this interferes with the ability to form mental representations on left side. (BISIACH)
Riddoch and Humphreys said neglect is…
An attentional deficit
Visual Agnosia is split up into…
Apperceptive and Associative agnosia
Patients with Apperceptive Agnosia…
Cannot accurately copy shapes or recognise them
Patients with Associative Agnosia…
Can accurately copy shapes but can’t recognise them. There is a disconnect between perception and “stored associations”
Marr’s Object Recognition Model includes…
Primal sketch, 2 1/2-D Sketch and 3D representation
(Ellis+Young, 1988) Initial representation is…
Low level analysis of image, damage=difficult to perceive
(Ellis+Young, 1988) Viewer centred representation is…
Higher level object representation, Damage=can’t form viewer centred representation, can;t differentiate between shapes, copy
(Ellis+Young, 1988) Object centred representation is…
High level representation w/o a viewpoint. Damage=can’t form object centred representation. Can’t recognise same object from different perspectives.
(Ellis+Young, 1988) Object recognition units are…
Stored descriptions of known objects, Damage=can’t differentiate between real and made up objects
(Ellis+Young, 1988) Semantic system is…
Stored meanings of all known objects, Damage=unable to attach meaning to objects
(Ellis+Young, 1988) Speech output lexicon is…
Part of language processing system, Damage=language impairment
Optic Aphasia is …
Patient can’t name visually presented objects but can do it of they touch the object or hear about it
