Quiz 5 Vocab Study

bipolar cells

- type of neuron in the retina that receives input directly from receptors
- located closer to the center of the eye
- sends messages to ganglion cells even closer to the eye

blind spots

- the area at the back of the retina where the optic nerve exists
- devoid of receptors

cones

- type of retinal receptor that contributes to color perception
- most abundant in and around the fovea (6 million per retina)

fovea

- a tiny area of the retina specialized for acute, detailed vision
- packed tightly with receptors
- nearly free of ganglion axons and blood vessels
- vision is dominated by what we see here

ganglion cells

- type of neuron in the retina that receives input from the bipolar cells
- their axons form the optic nerve

optic nerve

- the cranial nerve that serves the retina
- ganglion cell axons that exit through the back of the eye and continue to the brain

pupil

- the contractile aperture in the center of the iris of the eye; resembles a large black dot
- light enters the eye through an opening in the center of the
iris

retina

- the innermost light-sensitive membrane covering the back wall of the eyeball; it is continuous with the optic nerve
- the rear surface of the eye, which is lined with visual receptors

rods

- type of retinal receptor that detects brightness of light
- most abundant in the periphery of the eye and responds to faint light (120 million per retina)

astigmatism

- impaired eyesight resulting usually from irregular conformation of the cornea; common in nearsighted people
- a decreased responsiveness to one kind of line or another, caused by the asymmetric curvature of the eyes

blindsight

- the ability to respond in limited ways to visual information without perceiving it consciously

complex cells

- type of visual cortex cell located in areas V1 and V2 that responds to a pattern of light in a particular orientation anywhere within its large receptive fields

horizontal cells

- type of cell that receives input from receptors and delivers inhibitory input to bipolar cells

primary visual cortex

- aka area V1
- area of the cortex responsible for the first stage of visual processing

receptive field

- in each cell the specific region of sensory space in which an appropriate stimulus can drive an electrical response in a sensory neuron

retinal disparity

- the discrepancy between what the left and right eyes see

dorsal stream

- pathway through the parietal cortex is the action pathway or the "how" pathway, because of its importance for visually guided movements

fusiform gyrus

- brain area of the inferior temporal cortex that recognizes faces

motion blindness

- an impaired ability to perceive movement

saccades

- voluntary eye movements

visual agnosia

- inability to recognize or interpret objects in the visual field despite otherwise satisfactory vision