5. Occipital and Temporal Lobe: Perception + Memory Flashcards
Functional differentiation
Processing different properties of visual stimuli with different neuron types or different brain regions
Where do simple features occur?
In the primary visual pathway
Where do complex features occur?
In the extrastriate cortex
Extrastraute cortex
Contains V2, V3, V3a, V4, V5/MT
What do neurons in extrastriate cortex do differently to in the striate cortex
They signal global properties of visual scenes and objects rather than component properties
What are the names of the two streams
Dorsal and ventral stream
Where does the dorsal stream travel to?
Posterior parietal cortex
Where does the ventral stream go to?
Inferior temporal cortex
What kind of information does the dorsal stream carry?
Visuo spatial (where) and visuo motor (how)
What kind of information does the ventral stream carry?
Object analysis (what)
Visual agnosia
Deficits in aspects of visual perception without blindness, caused by occipital temporal damage
Optic ataxia
Deficits in visually guided reaching, caused by posterior parietal lobe lesions
What happens in the inferior temporal cortex?
Receives inputs from extrastriate cortex and forms the final stage in the visual processing hierarchy of the ventral stream.
How do neurons in the inferior temporal cortex respond?
Very specifically to shapes and objects, including faces
What happens in the medial temporal lobe?
It’s at the end of the visual processing hierachy. It combines inputs from ventral and dorsal stream and receives additional input from other sensory modalities.
