Biopsych Test 3

Front 1

sensitivity

Back 1

the ability to detect the presence of dimly lit objects

Front 2

acuity

Back 2

the ability to see the details of objects

Front 3

lens

Back 3

located behind the pupil, focuses incoming light on the retina

Front 4

ciliary muscles

Back 4

reduces/increases tension through contraction of this to focus the lens

Front 5

accomodation

Back 5

the process of adjusting hte configuration of the lenses to bring images into focus on the retina

Front 6

binocular disparity

Back 6

the difference in the position of the same image on the two retinas is greater for close objects than for diff. objects. the visual sistem uses this to construct on three-dimensional perception from two two-dimensional retinal images

Front 7

amacrine cells and horizontal cells

Back 7

retinal neurons specialized for lateral communication (comm. across the major channels of sensory input.

Front 8

receptor layers

Back 8

1 layer of the retina rods(dim) cones (light

Front 9

horizontal cells

Back 9

2 layer of the retina; modulate info

Front 10

bipolar cells

Back 10

3 layer of the retina; send messages from receptors to ganglion

Front 11

amacrine cells

Back 11

4 layer of the retina; modulate info

Front 12

retinal ganglion cells

Back 12

5 layer of the retina; axons send info to brain.

Front 13

blind spot

Back 13

caused by the gap in the receptor layer needed to allow the bundle of retinal ganglion cell axons to leave the eye.

Front 14

fovea

Back 14

.33 cm diameter indentation at the center of the retina, specialized for high acuity vision.

Front 15

completion

Back 15

the visual systems use of info provided by the receptors around the blind spot to fill in the gaps in retinal images.

Front 16

optic disk

Back 16

this is where axons leave the blind spot

Front 17

duplexity theory

Back 17

theory that cones and rods mediate different kinds of vision

Front 18

photopic vision

Back 18

cone-mediated vision that predominates in good lighting and provides high-acuity colored perceptions of the world; low sensitivity

Front 19

scotopic vision

Back 19

rod-mediated vision that predominates in dim light, and provides low acuity, but high sensitivity

Front 20

saccades

Back 20

very quick eye movements that allow brain to determine perception through integration of the information.

Front 21

temporal integration

Back 21

reason that the world does not vanish momentarily each time we blink.

Front 22

visual transduction

Back 22

the conversion of light to neural signals by the visual receptors

Front 23

rhodopsin

Back 23

a pigment extracted from rods. the degree that it absorbs light in various situations predicts how humans see under the very same conditions.

Front 24

retina-geniculate-striate pathways

Back 24

conduct signals from each retina to the primary visual cortex via the lateral geniculate nuclei of the thalamus.

Front 25

retinotopic

Back 25

each level of the system is organized like a map of the retina. two stimuli presented to adjacent areas of the retina excite adjacent neurons at all levels of the system.

Front 26

parvocellular layers (p layers)

Back 26

channel of communication running through the top four layers of the lateral geniculate nucleus. composed of small cell bodies. responsible fo rcolor, fine pattern details, stationary objects.

Front 27

magnocellular (m layers)

Back 27

through the bottom 2 layers of the lateral geniculate nucleus. responsible for movement.

Front 28

ommatidia

Back 28

the large receptors each with its own large axon of the horshoe crab, that mammallian animals lack.

Front 29

lateral inhibition

Back 29

when a receptor fires it inhibits its neighbors via the lateral neural network.

Front 30

receptive fild

Back 30

the area of the visual field within which it is possible for a visual stimulus to influence the firing of that neuron.