Quiz 5 Vocab Study

bipolar cells

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