Vision

Question 1

In 1838, he held that whatever excited a particular nerve establishes a special kind of energy unique to that nerve. Any activity by a particular nerve always conveys the same kind of information to the brain.

Answer 1

Johannes Muller

Question 2

The principle that any impulse in a given nerve sends the same kind of message to the brain.

Answer 2

Law of Specific Nerve Energies

Question 3

The coding of visual information in the brain does not duplicate the shape of the object that one sees.

Answer 3

From Neuronal Activity to Perception

Question 4

Route Within the Retina

Answer 4

Retina - Bipolar Cells - Ganglion Cells - Brain (in the form of optic nerve)

Question 5

It is numerous and diverse and atleast 29 types have been identified so far. It gets information from bipolar cells and sends it to other bipolar cells, other amacrine cells, or ganglion cells.

Answer 5

Amacrine Cells

Question 6

The point at which the axons of the ganglion cells exit.

Answer 6

Blind Spot

Question 7

Measures about 3mm x 5 mm in the center of the retina.

Answer 7

Macula

Question 8

The central portion of the macula, it is where the most precise vision comes in. It has the least impeded vision available.

Answer 8

Fovea

Question 9

Has better acuity or sensitivity to detail.

Answer 9

Foveal Vision

Question 10

Has better sensitivity to dim light. Can identify a shape much better than itself than it is surrounded by other objects.

Answer 10

Peripheral Vision

Question 11

Receptors that are more abundant in the periphery of the human retina, responds to faint light but are bleached by bright light and thus not very useful in bright daylight.

Answer 11

Rods

Question 12

Receptors that are more abundant in and around the fovea, are less active in dim light, and essential for color vision.

Answer 12

Cones

Question 13

Chemicals that release energy when struck by light. They are stable in the dark and consist of 11-cis-retinal bound to proteins called opsins.

Answer 13

Photopigments

Question 14

Requires comparing the responses of different kinds of cones.

Answer 14

Color Vision

Question 15

Shortest visible wavelength about 350mm.

Answer 15

Violet

Question 16

Longer wavelengths near 700mm.

Answer 16

Blue
Green
Yellow
Orange
Red

Question 17

The first to recognize that color required a biological explanation. Proposed that we perceive color by comparing the responses of some small number of receptors.

Answer 17

Thomas Young

Question 18

Believed that we perceive color through the relative rates of response by three kinds of cones.

Answer 18

Hermann von Helmhots

Question 19

Three Cone Types

Answer 19

Short Wavelength
Medium Wavelength
Long Wavelength

Question 20

Suggests that people discriminate among wavelengths by the ratio of activity across the three types of cones.

Answer 20

Trichromatic Theory

Question 21

Suggests that we perceive color in terms of paired opposites: red vs. green, yellow vs. blue, and white vs. black.

Answer 21

Ewald Herring

Question 22

The ability to recognize color of an object despite changes in lighting.

Answer 22

Color Constancy

Question 23

Suggests that the cortex compares information from various parts of the retina to determine the brightness and color perception for each area.

Answer 23

Edwin Land

Question 24

The inability to perceive color differences as most other people do.

Answer 24

Color Vision Deficiency (Color Blindness)

Question 25

A nucleus of the thalamus specialized for visual perception.

Answer 25

Geniculate Nucleus

Question 26

The point in space from which the light coming into the eye strikes the receptor.

Answer 26

Receptive Fields

Question 27

A mechanism by which stimulation in any area of the Retina suppresses the responses in neighboring areas, thereby enhancing the contrast at light-dark borders.

Answer 27

Lateral Inhibition

Question 28

Visual pathway begins its division if labor before it reaches the cerebral cortex. Different ganglion cells react differently to the same input.

Answer 28

Concurrent Pathways in the Retina and Lateral Geniculate

Question 29

With smaller cell bodies and small receptive fields. Located mostly in or near the fovea. Well suited to detect visual details, very sensitive to color and each excited by some colors and inhibited by others.

Answer 29

Parvocellular Neurons

Question 30

With larger cell bodies and receptive fields. Distributed fairly evenly throughout the retina, including the periphery. Respond strongly to moving stimuli and to large overall patterns but not to colors and visual details.

Answer 30

Magnocellular Neurons

Question 31

Have smaller cell bodies and occur throughout the retina instead of being clustered near the fovea.

Answer 31

Koniocellular Neurons

Question 32

It is the area of the cortex responsible for the first stage of visual processing. Responds to any kind of visual stimulus and is active even when we close our eyes.

Answer 32

Primary Visual Cortex (V1/Striate Cortex)

Question 33

Processes the information further and transmits it to the additional areas.

Answer 33

Secondary Visual Cortex (V2)

Question 34

The region of cortex located immediately in front of V2. Some controversy exists regarding the extent of this area, with some researchers proposing that this is in fact a complex of two or three functional subdivisions.

Answer 34

V3

Question 35

An area particularly important for color contrast; it has cells that contribute to visual attention.

Answer 35

V4

Question 36

Cells in this area respond selectively to a stimulus moving in a particular direction, almost independently of the size, shape, brightness, or color of the object.

Answer 36

Middle Temporal Cortex (MT/V5)

Question 37

The inability to recognize objects despite otherwise satisfactory vision.

Answer 37

Visual Agnosia

Question 38

They can read, recognize familiar people from their voices and sometimes even clothing, so their problem is specific to faces.

Answer 38

Prosopagnosia

Question 39

Able to see objects but unable to determine whether they are moving or if so, in which direction or how fast.

Answer 39

Motion Blind