Vision 2

Binocular Disparity

• Your two eyes are separated by ~6cm. Each gets a slightly different view of the world

• The brain computes the difference between these two views

Ocular Dominance

• Most V1 neurons respond to input from both eyes — but with a preference for one (This preference = ocular dominance)

Fusiform Face Area (FFA)

region in the IT Cortex that responds preferentially to faces over objects, scenes, or other categories

Monocular Deprivation

(eg. sowing one eye shut); alter ocular dominance; no affects on the retina and

Amblyphobia

visual defects caused by misaligned eyes

• Treated by covering the healthy eye for several hours a day

Dorsal Stream

Projects through the parietal lobe to represent motion and location

• “where” pathway

• V1 → Parietal Cortex

Ventral Stream

Projects through the temporal lobe to represent form (color, shape) and object/face recognition

• “what” pathway

• V1 → Inferotemporal Cortex

Area MT/V5

Neurons respond directly to the direction and speed of motion; recieves input from V1 and direct subcortical routes

• important for survival: predators, prey, social signals, catching objects

Building Complexity from Features

Visual Form Agnosia

cannot perceive the shape or orientation of objects despite normal vision acuity

Fusiform Face Area (FFA)

region in the IT cortex that responds preferentially to faces over objects, scenes, or other categories

Prospagnosia

inability to recognize faces (despite normal visual acuity)

Super-recognizers

enhanced face recognition; scouted for police/detective teams

Blindsight

can navigate around obstacles in blind field, but dney having seen them