Biopsychology Chapter 6

Front 1

Sensitivity

Back 1

ability to detect dimly lit objects

Front 2

Acuity

Back 2

ability to see details of objects

Front 3

Ciliary Muscles

Back 3

ligaments holding lens in place, helps lens refract light, bringing close object into focus

Front 4

Accommodation

Back 4

Process of adjusting lens to bring images into focus on retina.

Front 5

Binocular Disparity

Back 5

Difference in position of same image on two retinas; larger for close objects

- use degree of binocular disparity to construct 3D perception

Front 6

Receptors

Back 6

Specialized cells, receive chemical, mechanical, or radiant signals from the environment ; proteins that contain binding sites for particular neurotransmitters.

Front 7

Horizontal Cells

Back 7

Types of retinal neurons whose specialized function is lateral communication.

Front 8

Bipolar Cells

Back 8

Bipolar neurons that form the middle layer of the retina.

Front 9

Amacrine Cells

Back 9

Type of retinal neurons - specialized function of lateral communication.

Front 10

Retinal Ganglion Cells

Back 10

Retinal neurons whose axons leave the eyeball and form the optic nerve.

Front 11

Blind Spot

Back 11

Area on the retina where the bundle of axons of the retinal ganglion cells penetrate the receptor layer and leave the eye as the optic nerve.

Front 12

Fovea

Back 12

Central indentation of the retina, which is specialized for high-acuity vision.

Front 13

Completion

Back 13

Visual system's automatic use of information obtained from receptors around the blind spot, or scotoma, to create a perception of the missing portion of the retinal image.

Front 14

Surface Interpolation

Back 14

Process by which the visual system perceives large surfaces, by extracting information about edges and from it, inferring the appearance of adjacent.

Front 15

Cones

Back 15

Visual receptors in the retina that mediate high acuity colour vision in good lighting.

Front 16

Rods

Back 16

Visual receptors in the retina that mediate achromatic, low-acuity vision under dim light.

Front 17

Duplexity Theory

Back 17

Theory that cones and rods mediate photopic and scotopic vision, respectively.

Front 18

Photopic Vision

Back 18

Cone-mediated vision, which predominates when lighting is good.

Front 19

Scotopic Vision

Back 19

Rod-mediated vision, predominates in dim light.

Front 20

Photopic Spectral Sensitivity Curve

Back 20

Graph of the sensitivity of cone-mediated vision to different wavelengths of light.

Front 21

Scotopic Spectral Sensitivity Curve

Back 21

Graph of sensitivity of rod-mediated vision to different wavelengths of light.

Front 22

Purkinje Effect

Back 22

In intense light, red and yellow wavelengths look brighter than blue or green wavelengths of equal intensity; in dim light, blue and green wavelengths look brighter than red and yellow wavelengths of equal intensity.

Front 23

Fixational Eye Movements

Back 23

Involuntary movements of the eyes (tremor, drifts, and saccades) that occur when person tried to fix their gaze on a point.

Front 24

Saccades

Back 24

Rapid movements of the eyes between fixations.

Front 25

Transduction

Back 25

Conversion of one form of energy to another.

Front 26

Rhodopsin

Back 26

The photopigment of rods.

Front 27

Absorption Spectrum

Back 27

Graph of the ability of a substance to absorb light of different wavelengths.

Front 28

Retina-geniculate-striate Pathways

Back 28

Major visual pathway from each retina to the striate cortex (primary visual cortex) via the lateral geniculate nuclei of the thalamus.

Front 29

Primary Visual Cortex

Back 29

Area of cortex that receives direct input from the lateral geniculate nuclei (aka striate cortex).

Front 30

Lateral Geniculate Nuclei

Back 30

Six-layered thalamic structures that receive input from the retinas and transmit structure that receive input from the retinas and transmit their output to primary visual cortex.

Front 31

Retinotopic

Back 31

Organized, like the primary visual cortex, according to a map of the retina.

Front 32

Parvocellular Layers

Back 32

Layers of the lateral geniculate nuclei that are composed of neurons with small cell bodies; top four layers (called P layers).

Front 33

Magnocellular Layers

Back 33

Layers of the lateral geniculate nuclei composed of neurons with large cell bodies; the bottom two layers (called M layers).

Front 34

Contrast Enhancement

Back 34

Intensification of the perception of edges.

Front 35

Lateral Inhibition

Back 35

Inhibition of adjacent neurons or receptors in a topographic array.

Front 36

Receptive Field

Back 36

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

Front 37

On-center Cells

Back 37

Visual neurons respond to lights shone in the center of their receptive fields with "on" firing to lights shone in the periphery of their fields with "off" firing.

Front 38

Off-center Cells

Back 38

Visual neurons that respond to lights shone in the center of their receptive fields with "off" firing and to lights shone in the periphery of their fields with "on" firing.

Front 39

Simple Cells

Back 39

Neurons in the visual cortex that respond maximally to straight-edge stimuli in a certain position and orientation.

Front 40

Complex Cells

Back 40

Neurons in visual cortex that respond optimally to straight-edge stimuli in certain orientation in any part of their receptive field.

Front 41

Component Theory

Back 41

The relative amount of activity produced in three different classes of cones by light determines its perceived colour (AKA trichromatic theory)

Front 42

Opponent-process Theory

Back 42

Theory that a visual receptor or a neuron signals one color when it responds in one way (eg, by increasing its firing rate) and signals the complementary color when it responds in the opposite way (eg. by decreasing its firing rate).

Front 43

Complementary Colours

Back 43

Pairs of colours that produce white or gray when combined in equal measure; every colour has a complementary color.

Front 44

Colour Constancy

Back 44

Tendency of an object to appear the same colour even when the wavelengths of light that it reflects change.

Front 45

Retinex Theory

Back 45

Land's theory that colour of an object determined by its reflectance, which the visual system calculates by comparing the ability of adjacent surfaces to reflect short, medium, long wavelengths.

Front 46

Dual-opponent Colour Cells

Back 46

Neurons that respond to the differences in the wavelengths of light stimulating adjacent areas of their receptive field.

Front 47

Cytochrome Oxidase

Back 47

Enzyme present in part. high concentrations in mitochondria of dual-opponent colour cells of visual cortex.

Front 48

Blobs

Back 48

Peglike, cytochrome oxidase-rich, dual-opponent colour columns.

Front 49

Secondary Visual Cortex

Back 49

Areas of cerebral cortex that receive most of input from primary visual cortex.

Front 50

Visual Association Cortex

Back 50

Areas of cerebral cortex receive input from areas of secondary visual cortex as well as from secondary cortex of other sensory systems.

Front 51

Prestriate Cortex

Back 51

The band of tissue in the occipital lobe that surround the primary visual cortex and contains areas of secondary visual cortex.

Front 52

Inferotemporal Cortex

Back 52

Cortex of the inferior temporal lobe, which is located in area of secondary visual cortex that is involved in object recognition.

Front 53

Posterior Parietal (association) Cortex

Back 53

Area of association cortex that receives input from the visual, auditory, and somatosensory systems and is involved in the perception of spatial location and guidance of voluntary beh.

Front 54

Scotoma

Back 54

Area of blindness produced by damage to, or disruption of, an area of the visual system.

Front 55

Perimetry Test

Back 55

The procedure used to map scotomas.

Front 56

Hemianopsic

Back 56

Having a scotoma that covers half of the visual field.

Front 57

Conscious Awareness

Back 57

Ability to perceive one's experiences; typically inferred from the ability to verbally describe them.

Front 58

Blindsight

Back 58

Ability of some patients who are blind as a consequence of cortical damage to unconsciously see some aspects of their visual environments.

Front 59

Dorsal Stream

Back 59

Group of visual pathways that flow from primary visual cortex to dorsal prestriate cortex to the posterior parietal cortex; one theory states - function is the control of visually guided behaviour.

Front 60

Ventral Stream

Back 60

Group of visual pathway that flow from the primary visual cortex to ventral prestriate cortex to the inferotemporal cortex; according to one theory, its function is conscious visual perception.

Front 61

"Where" vs. "What" Theory

Back 61

Theory that the dorsal stream mediates perception of where things are and ventral stream mediates perception of what things are.

Front 62

"Control of Behaviour" vs. "Conscious Perception" Theory

Back 62

Theory that dorsal stream mediates beh. interactions w/ objects and the ventral stream mediates conscious perception of objects.

Front 63

Prospoagnosia

Back 63

Visual agnosia for faces.

Front 64

Agnosia

Back 64

Inability to consciously recognize sensory stimuli of a particular class that is not attributable to a sensory deficit or to verbal or intellectual impairment.

Front 65

Visual Agnosia

Back 65

Failure to recog. visual stimuli that is not attributable to sensory, verbal, or intellectual impairment.

Front 66

Fusiform Face Area

Back 66

Area of human cortex, located at boundary btwn occipital & temporal lobes, that is selective activated by human faces.

Front 67

Akinetopsia

Back 67

Deficiency in the ability to perceive motion, often results from damage to dorsal visual pathway.

Front 68

MT Area

Back 68

Area of cortex, located near the junction of the temporal, parietal, and occipital lobes, function appears to be the perception of motion.

Front 69

Sensory Feedback

Back 69

sensory signals that are produced by a response and are often used to guide the continuation of the response.

Front 70

Frontal Eye Field

Back 70

Small area of prefrontal cortex that controls eye movements.

Front 71

Apraxia

Back 71

Disorder where patients have great difficulty performing movements when asked to do so out of context but can readily perform them spontaneously in natural situations.