Sensory Systems and Perception: Vision Overview

Cornea

The transparent outer layer of the eye that provides most of the eye’s refractive power.

Pupil

The opening in the center of the iris that regulates light entry into the eye.

Rods

Photoreceptors that are more sensitive to light and responsible for low-light vision, but do not provide color perception.

Cones

Photoreceptors responsible for color vision and fine detail, with three types: S (blue), M (green), L (red).

Phototransduction

The process by which photoreceptors convert light into electrical signals.

Lateral Geniculate Nucleus (LGN)

The part of the thalamus that processes visual signals before they reach the primary visual cortex.

V1 (Primary Visual Cortex)

The area of the brain that processes basic visual features such as edges, orientation, and motion.

Dorsal Stream

The 'Where/How' pathway that processes spatial location and movement.

Ventral Stream

The 'What' pathway that specializes in object recognition and form processing.

Trichromatic Theory

The theory that color vision depends on three types of cones (S, M, L).

Agnosia

A disorder characterized by the inability to recognize objects, often due to damage to the ventral stream.

Motion Perception

The process by which the visual system detects and tracks object motion.

Blindsight

A condition in which individuals with V1 lesions can respond to visual stimuli despite lacking conscious perception.

Depth Perception

The ability to perceive the world in three dimensions and judge distances, using binocular and monocular clues.

Edge Detection

The process by which the visual system enhances contrast using lateral inhibition.

Fovea

responsible for sharp central vision because of its high concentration of cones,

Hemianopia

Loss of vision in half of the visual field due to lesions in the primary visual cortex (V1).

What is the function of the cornea in the eye?

The cornea provides most of the eye’s refractive power and protects the inner structures of the eye.

How does the pupil regulate light entry into the eye?

The pupil changes size to adjust the amount of light that enters the eye, dilating in low light and constricting in bright light.

What is the role of rods in vision?

Rods are photoreceptors that are sensitive to light and enable vision in low-light conditions, but they do not provide color information.

What types of photoreceptors are responsible for color vision?

Cones, specifically the three types: S (blue), M (green), and L (red), are responsible for color vision.

What happens during the process of phototransduction?

Phototransduction is the process by which photoreceptors convert light into electrical signals that can be processed by the brain.

What is the difference between the dorsal and ventral streams in the visual processing pathways?

The dorsal stream processes spatial location and movement (the 'Where/How' pathway), while the ventral stream specializes in object recognition and form processing (the 'What' pathway).