Charting the visual streams and Receptive fields

Separation of information is maintained in V2 how does it accomplish this

Information is divided between thin stripes, thick stripes, and pale zones

What type of information does thin stripes recieve

Information about color from blobs

What type of information do thick strips recieve?

Information about motion from interblobs

What type of information do the pale zones recieve

Information about form from interblobs.

Moving past v2 the segragation of information is now maintained in the dorsal and ventral streams. Describe what the dorsal stream recieves and what the visual stream recieves

The dorsal stream recieves information about form and motion. The ventral stream recieves information about form and color.

Receptive field

The small circular patch that each retinal ganglion cell responds to.

Monocular blindness

Destruction of the retina or optic nerve of one eye, producing loss of sight in that eye.

lHomonymous Hemianopia

Blindness of an entire left or right visual field

Quadrantanopia

Blindness of one quadrant of the visual field

Scotoma

Small blindspot in the visual field caused by a small leasion or migraines of the visual cortex.

How are the cells that lie along the midline of the visual field connected?

Via the corpus callosum

Why is the connection of the cells that lie along the midline of the visual field so important?

So that the left and right visual field can be combined

What do retinal ganglion cells respond to and not respond to?

They respond to presence or absence of light but not shape.

On center cells

Excited by light in the center of the visula field, inhibited when light falls on the surround

Light across the whole receptive field produces

weak excitation

Are receptive fields separate?

No they overlap

Luminance contrast

The amount of light reflected by an object relative to its surroundings

What is luminance contrast measured by and why?

Retinal ganglion cells; to tell the world about edges

What is the difference between v1 neurons and retinal ganglion cells

v1 neurons have much larger receptive fields.

Simple cells

A receptive field with a rectangular on-off arrangement

Complex cell

Maximally excited by bars of light moving in a specific direction through receptive fields. Location doesn’t matter.

Hyoercomplex cells

Very responsive to moving bars of light amd also have a strong inhibitory area at one end of the receptive field

Subtractive color mixing

Cones getting a wide range of color from just three (red green and blue)

Additive Color mixing

Increases light to make color

What does the trichromatic theory of color vision state?

If all cones were equally active we see white

What does the opponent process theory of color vision state?

Emphasizes the importance of speicific color opponency pairs (red vs green) (blue vs yellow)

Lateral intraparietal area is for

eye movements

Anterior intraparietal area

Visual control of grasping

Parietal reach region

Visually guided reaching

prosopagnosia

: inability to recognize faces

achromatopsia

inability to recognize colors

visual-form agnosia:

inability to recognize objects or drawings of objects. They can still draw it themselves though they just cant recognize.

optic ataxia

deficit in the visual control of reaching and other movements

Ebbinghaus is primarily a

Ventral stream phenomenon