Visual Info Processing

Question 1

Steps in Vision (4)

Answer 1

1. Light reflect off object and hits eyes.
2. Light activates primary receptor cells
3. Primary receptor cells respond to light stimulation: Hyperpolarization (send neural signals to other neurons in retina)
4. Axons from ganglion cells converge (optic nerve) ->optic chiasm ->subcortical structures ->primary visual cortex (V1)

Question 2

Rods

Answer 2

• peripheral vision
• ~130 million, prim. outside of fovea
• Black&white vision (less light required to trigger response w/ rod)
• Less detail (low acuity)

Question 3

Cones

Answer 3

• foveal vision
• About 7 million, primarily in center of retina (fovea)
• Color vision
• More detail (high acuity)

Question 4

Lateral Geniculate Nucleus

&

Temporal

Answer 4

Subcortical struc involved in visual proc

• LGN: object recognition
• “What” recognition

Question 5

Superior Colliculus

&

Parietal

Answer 5

Subcortical struc involved in visual proc

• locating objects in space
• “Where” pathway

Question 6

Absorption/Scattering

Answer 6

The brain receives a partially “summarized” record of the original stimulus

Only a small portion of primary receptors have their own private “pipeline” to the brain

Question 7

Foveal Vision

Answer 7

High Acuity

Receptor order:

Ganglion->Bipolar->Cones

Question 8

Peripheral Vision

Answer 8

20 degrees from fovea

less acute

Order of receptors:

Ganglion->Bipolar->Rods

Question 9

Blindspot

Answer 9

Located 20 degrees from fovea