Week 2: Visual System – Detailed Cornell-Style Notes

A set of vocabulary flashcards covering key concepts from the Visual System lecture.

Phototransduction

The process by which light is captured by photoreceptors in the retina and converted into an electrochemical signal.

Rods

Photoreceptors that are sensitive to dim light and provide black-and-white vision; have high sensitivity but poor acuity.

Cones

Photoreceptors that function in bright light, allowing for color vision; have lower sensitivity but high acuity.

Fovea

The central pit in the retina responsible for high visual acuity due to minimal neural tissue.

Blind spot

An area in the retina where there are no photoreceptors, located at the optic disc.

ON-centre bipolar cell

A type of bipolar cell that depolarizes in response to a decrease in glutamate release, activated by light.

OFF-centre bipolar cell

A type of bipolar cell that depolarizes in response to an increase in glutamate release, activated by dark.

Optic chiasm

The crossing point where nasal retinal fibers cross to the opposite side, ensuring visual fields are processed in the correct hemisphere.

Adaptation

The process by which photoreceptor sensitivity decreases with prolonged exposure to light.

Range fractionation

A process where rods and cones work together to handle a wide range of luminance.

Retinotopic mapping

An organization principle where adjacent retinal neurons correspond to adjacent cortical neurons, forming an orderly visual map.

Ventral stream

The pathway in the brain that processes object and face recognition, involving conscious perception.

Dorsal stream

The pathway in the brain that is responsible for spatial awareness and visually guided actions.

Visual form agnosia

A condition where an individual can describe the shape of an object but cannot recognize or name it.

Lateral inhibition

A process where the activation of one neuron suppresses the activity of neighboring neurons, enhancing edge contrast.

Receptive field

The specific area of sensory space that causes a neuron to fire when stimulated.