Visual Brain Flashcards
Magnocellular
(Layers 1-2) motion sensitive, high light sensitivity (poor acuity): origin is large parasol (receptive field) rods and cones in the peripheral retina
Parvocellular
(Layers 4-6) acuity / fine details, color processing: midget retinal ganglion cells, origin is single cones in fovea
Koniocellular
varied functions: origin is rods & cones and receive input from the bistratified retinal ganglion cells, larger receptive fields, lower acuity than P cell
Superior Colliculus
Receives input from the optic nerve, cortex, & basal ganglia and Controls eye movements (saccades - rapid and sudden movement)
Complex Cells
Respond to edges/bars with a particular orientation. Unlike simple cells, they don’t prefer stationary stimuli and often have a direction of motion preference
End-stopped Cells
Respond when the ends of lines are in their receptive fields
Optic Chiasm
where the optic nerve from each eye splits in half
Optic Tract
optic nerve starting at the optic chiasm and continuing into the brain
Contralateral Representation of Space
left visual world goes to the right side of the brain and vice versa
Ipsilateral Organization
temporal retina projects to the same side of the brain
Where do the axons that did not go to the thalamus go instead?
Superior colliculus
Lateral Geniculate Nucleus
bilateral structure in the thalamus that relays info from the optic nerve to visual cortex
Orienting Turing Curve
graph that demonstrates the typical response of a simple cell to stimuli or different orientations
Ocular Dominance Column
(V1 column) neurons receive input from only the left eye or only the right eye
Orientation Column
(V1 column) neurons have similar responses to the orientation of a shape presented to those neurons
Hypercolumn
1-mm block of V1 containing both the ocular dominance and orientation columns for a particular region in visual space
Extrastriate Cortex
collective terms for visual areas in the occipital lobe
V2
second area in visual cortex that receives input (starts with visual associations)
Inferotemporal Cortex
region in temporal lobe that receives input from the ventral visual pathway ; object identification
MT (V5)
area of occipital lobe in dorsal pathway ; motion detection and perception
Blindsight
presence of visual abilities even though a person experiences blindness because of damage to V1
Scotoma
area of partially or completely destroyed cells resulting in a blind spot in a particular region of visual field
Conjugate Gaze Palsies
neurological disorder that affect the ability of the eyes to coordinate their movements (may affect both vertical and horizontal directions)
Internuclear Ophthalmoplegia
conjugate palsy resulting from long term damage to the brain stem region (Medial Longitudinal Fasciculus)
