Cortical Vision Flashcards
How many representations of the visual world exist in the visual cortex?
Multiple!
What are the extrastriate areas?
Higher-order visual areas beyond the striate cortex that also contain representations of the retina
What is a receptive field?
A specific, limited region of space that each visually sensitive cell responds to
True or false: different areas of human extrastriate visual cortex are involved in processing different attributes of vision
True!
The two main projection routes from the primary visual cortex (V1) to extrastriate visual cortex and their purpose
Dorsal stream: codes motion and location (WHERE)
Ventral stream: processes detailed stimulus features and object identity (WHAT)
4 facts about extrastriate cortex
Not every area is connected with each other - it’s complex but not random.
Each visual area has topographical representation of the contralateral hemifield.
Maps of visual experience differ with each visual area in terms of the info it represents.
Where info from retinogeniculostriate pathway is integrated and made sense of.
Area in extrastriate cortex associated with ventral stream and what it responds to
V4, responds to a combination of colour and form
Area in extrastriate cortex associated with dorsal stream and what it responds to
V5, selective for direction and speed of motion (damage disrupts motion perception)
What are endogenous eye movements?
Voluntary eye movements
Where does the superior colliculus receive info from?
The retina
Where does the superior colliculus project info?
Down to the saccade generators in the brain stem
Where does the frontal eye field project info?
Down to the saccade generators in the brain stem
Which are generally easier, exogenous or endogenous eye movements?
Exogenous! or reflexive, whatever you wanna call it
What is the frontal eye field normally involved in?
Generating voluntary saccades, or eye movements
What happens if a TMS is placed over the superior prefrontal cortex?
It delays contralateral endogenous saccades by disrupting the normal operation of the frontal eye field
