Visual Parallel Processing

At least __ brain areas involved in vision

80

Visual processing involves

Object shape
Color
Location
Movement (perception of...)

The Secondary Visual Cortex (V2)

Receives info. from V1 ➔ Processes it further ➔ Sends results to other areas

Info. transferred b/t V1 & V2 in ___________ manner

reciprocal

Ventral Stream (_________ Regions)

Temporal

The “what” path that specialized for identifying & recognizing objects

Ventral Stream

Dorsal Stream (________Regions)

Parietal

Dorsal Stream

The “how” path. Important for visually-guided movements

True or False: Damage to either stream will produce the same deficits

False: Damage to either stream will produce entral Stream - Can see where objects are but cannot
identify them deficits

Ventral Stream - Can see _________ objects are but cannot ________ them

where…………identify

Can identify objects but not know where they are

Dorsal Stream Damage

Receptive Fields become _______________ as visual info. goes from simple ➔ complex cells & then to other brain
areas

larger & more specialized

Contains cells that respond selectively to complex
shapes... but are insensitive to distinctions that are critical to other cells. Cells located here respond to identifiable objects

Inferior Temporal Cortex

Damage to the __________ causes Visual Agnosia (damage to pattern pathway in
temporal cortex)

Inferior Temporal Cortex

Recognizing Faces

Begins shortly after birth ➔ Newborns show strong preference for “right-side-up”
face. Facial recog. develops gradually into adolescence

Color perception is dependent on?

The light reflected on an object &...
How it compares w/ objects around it

Area poss. responsible for visual attention & color constancy (ability to recognize something as being same color despite changes in lighting)

Area V4

Motion Perception occurs in?

Several Areas in All Cortical Lobes:
Middle-Temporal Cortex (MT/V5),
Cells in dorsal area of Medial Superior Temporal (MST) Cortex, and both receive input from the Magnocellular Path (color-insensitive)

responds to stimulus moving in a particular direction

Middle-Temporal Cortex (MT/V5)

Cells in dorsal area of _______________________ (MST) Cortex respond to expansion, contraction, or rotation of visual stim.

Medial Superior Temporal

Motion Blindness

Inability to determine direction, speed, & whether / not objects are moving

What causes Motion Blindness

Damage in area MT/V5

True or False: Some people are blind except for ability to detect direction something is moving in

True: Area MT/V5 probably gets some visual input despite signif. damage to area V1

Saccades

A decrease in Visual Cortex activity during quick eye movement. Neural activity & blood flow decrease 75 milliseconds before & during eye movement

Purpose of Saccades

Help prevent confusion or blurring of images during eye movement