Biological Psychology - Vision

Flashcards about Biological Psychology - Vision. These flashcards are in the vocabulary style.

Law of specific nerve energies

States that activity by a particular nerve always conveys the same type of information to the brain.

Pupil

Opening in the center of the iris through which light enters the eye.

Retina

Rear surface of the eye, lined with visual receptors.

Bipolar cells

Cells located closer to the center of the eye that receive messages from visual receptors.

Amacrine cells

Cells that receive messages from bipolar cells and send them to other bipolar, ganglion, or amacrine cells.

Optic nerve

Axons of ganglion cells that join one another to form a nerve that travels to the brain.

Blind spot

The point at which the optic nerve leaves the eye, also where blood vessels enter and leave.

Rods

Visual receptors most abundant in the periphery of the eye, respond to faint light.

Cones

Visual receptors most abundant in and around the fovea, essential for color vision.

Photopigments

Chemicals contained by both rods and cones that release energy when struck by light.

Trichromatic Theory

Color perception occurs through the relative rates of response by three kinds of cones.

Opponent-Process Theory

Suggests that we perceive color in terms of paired opposites.

Retinex theory

The cortex compares information from various parts of the retina to determine the brightness and color for each area.

Color constancy

The ability to recognize color despite changes in lighting.

Color vision deficiency

An impairment in perceiving color differences.

Horizontal cells

Cells in the eye that make inhibitory contact onto bipolar cells.

Optic chiasm

The place where the two optic nerves leaving the eye meet.

Lateral Inhibition

Sharpens contrasts to emphasize the borders of objects through the reduction of activity in one neuron by activity in neighboring neurons.

Receptive field

The part of the visual field that either excites or inhibits a cell in the visual system of the brain.

Parvocellular neurons

Neurons mostly located in or near the fovea, highly sensitive to detect color and visual detail.

Magnocellular neurons

Neurons distributed evenly throughout the retina, highly sensitive to large overall pattern and moving stimuli.

Primary visual cortex (V1)

Receives information from the lateral geniculate nucleus and is the area responsible for the first stage of visual processing.

Blindsight

An ability to respond to visual stimuli that they report not seeing.

Simple cells

Have fixed excitatory and inhibitory zones; response increases with light in the excitatory zone and decreases with light in the inhibitory.

Complex cells

Located in V1 or V2, these cells have large receptive fields, respond to specific orientations, and react best to moving stimuli.

End-stopped/hypercomplex cells

Like complex cells, but with strong inhibitory end; respond to bar-shaped light within a set range of their large receptive field.

Feature detectors

Neurons whose response indicate the presence of a particular feature/stimuli.

Stereoscopic Depth Perception

A method of perceiving distance in which the brain compares slightly different inputs from the two eyes, relies on retinal disparity.

Strabismus

A condition in which the eyes do not point in the same direction.

Astigmatism

Refers to a blurring of vision for lines in one direction caused by an asymmetric curvature of the eyes.