BIOC44 Vision Notes

Photoreceptors

Cells in the retina that convert light into electrical signals; includes rods and cones.

Rods

Photoreceptors that are very sensitive and work well in low light conditions.

Cones

Photoreceptors that are less sensitive but enable high acuity vision, responsible for color and fine detail.

Transduction

The process of converting light into electrical signals in the visual system.

Horizontal Cells

Lateral inhibitory interneurons that connect photoreceptors to each other and to bipolar cells.

Lateral Inhibition

A mechanism that enhances contrast by comparing signals from neighboring photoreceptors.

Bipolar Cells (ON & OFF Types)

Relay cells in the retina; ON bipolars activate with light increase, OFF bipolars with light decrease.

Amacrine Cells

Diverse inhibitory interneurons in the retina that shape timing, motion detection, and contrast enhancement.

Retinal Ganglion Cells (RGCs)

Output neurons of the retina that encode features and send processed visual information to the brain.

Signal-to-Noise Ratio (SNR)

A measure that describes the level of a desired signal compared to the level of background noise.

Feature Extraction

The process of identifying and encoding important visual information, such as edges and motion, in the retina.

Gain Control

The ability of retinal cells to adjust signals based on overall luminance to prevent saturation.