Psychology 101- Chapter 3

Front 1

Absolute threshold

Back 1

The minimum amount of energy in a sensory stimulus detached 50 percent of the time.

Front 2

Signal detection theory

Back 2

A theory that assumes that the detection of faint sensory stimuli depends not only upon a person's psychological sensitivity to a stimulus but also upon his decision criterion for detection, which is based on nonsensory factors.

Front 3

Difference threshold

Back 3

The minimum difference between two sensory stimuli detached 50 percent of the time. The difference threshold is also sometimes referred to as the just noticeable difference, of jnd.

Front 4

Weber's law

Back 4

For each type of sensory judgement that we can make, the measured difference threshold is a constant fraction of the standard stimulus value used to measure it. This constant fraction is different for each type of sensory judgement.

Front 5

Steven's power law

Back 5

The percieved magnitude of a stimulus is equal to its actual physical intensity raised to some constant power. The constant power is different for each type of sensory judgement.

Front 6

Sensory adaptation

Back 6

Our sensitivity to unchanging and repetitious stimuli disappears over time.

Front 7

Wavelength

Back 7

The distance in one cycle of a wave, from one crest to the next.

Front 8

Amplitude

Back 8

The amount of energy in a wave, its intensity, which is the height of the wave at its crest.

Front 9

Frequency

Back 9

The number of times a wave cycles in 1 second.

Front 10

Transduction

Back 10

The conversion of physical energy into neural signals that the brain can understand.

Front 11

Accomodation

Back 11

The focusing of light waves from objects of different distances directly on the retina.

Front 12

Nearsightedness

Back 12

A visual problem in which the light waves from distant objects are focused in front of the retina, blurring images of these objects.

Front 13

Farsightedness

Back 13

A visual problem in which the light waves from nearby objects are focused behinf the retina, blurring the images of these objects.

Front 14

Retina

Back 14

The light-sensitive layer of the eye which is composed of three layers of cells-ganglion, bipolar, and receptor (rods and cones).

Front 15

Rods

Back 15

Receptor cells in the retina that are principally responsible for dim light and peripheral vision.

Front 16

Cones

Back 16

Receptor cells in the retina that are principally responsible for bright light and color vision.

Front 17

Fovea

Back 17

A tiny pit in the center of the retina filled with cones.

Front 18

Dark adaptation

Back 18

The process by which the rods and cones through internal chemical changes become more and more sensative to light in dim light conditions.

Front 19

Trichromatic theory

Back 19

A theory of color vision which assumes that there are three types of cones, each only activated by wavelength ranges of light corresponding roughly to blue, green, and red. It further assumes that all of the various colors that we can see are mixtures of various levels of activation of the three types of cones. If all three are equally activated, we see white.

Front 20

Additive mixtures

Back 20

Direct mixtures of different wavelengths of light in which all of the wavelengths reach the retina and are added together.

Front 21

Subtractive mixtures

Back 21

Mixtures of wavelenghts of light in which some wavelengths are absorbed (subtracted) and so do not get reflected from the mixtures to the retina.

Front 22

Complementary colors

Back 22

Wavelengths of light that when added together produce a shade of white.

Front 23

Opponent-process theory

Back 23

A theory of color vision which assumes that there are three opponent-process cell systems (red-green, blue-yellow, and black-white) which processes color information after it has been processed by the cones. The colors in each system oppose one another in that if one color is stimulated, the other is inhibited.

Front 24

Hair cells

Back 24

The receptor cells for hearing. The line the basliar membrane inside the cochlea.

Front 25

Nerve deafness

Back 25

Hearing loss created by damage to the hair cells or the auditory nerve fibers in the inner ear.

Front 26

Conduction deafness

Back 26

Hearing loss created by damage to one of the structures in the ear responsible for mechanically conducting the auditory information to the inner ear.

Front 27

Place theory

Back 27

A theory of pitch perception which assumes that there is a specific location along the basliar membrane which will maximally respond to a particular frequency, thereby indicating the pitch to the brain. As this location goes down the basliar membrane from the oval window, the pitch goes down from 20,000 Hz. to 20 Hz.

Front 28

Frequency theory

Back 28

A theory of pitch perception which assumes that the frequency of the sound wave is mimicked by the firing rate of the entire basliar membrane.

Front 29

Volley principle

Back 29

Cells taking turns firing will increase the maximum firing rate rate for a group of cells.

Front 30

Sensation

Back 30

The initial information gathering and recording by the sensory structures.

Front 31

Perception

Back 31

The interpretation by the brain of sensory information.

Front 32

Bottom-up processing

Back 32

The processing of incoming sensory information as it travels up from the sensory structures to the brain.

Front 33

Top-down processing

Back 33

The brain's use of knowledge, beliefs, and expectations to interpret sensory information.

Front 34

Perceptual set

Back 34

The interpretation of ambiguous sensory information in terms of how our past experiences have set us to percieve it.

Front 35

Contextual effect

Back 35

The use of the present context of sensory information to determine its meaning.

Front 36

Figure-and-ground principle

Back 36

The Gestalt perceptual organizational principle that the brain organizes sensory information into a figure or figures (the center of attention) and ground (the less distinct background).

Front 37

Closure

Back 37

The Gestalt perceptual organizational principle that the brain completes (closes) incomplete figures to form meaningful objects.

Front 38

Subjective contour

Back 38

A line or shape that is percieved to be present but does not really exist. The brain creates it during perception.

Front 39

Perceptual constancy

Back 39

The perceptual stability of the size, shape, and brightness, and color for familiar objects seen at varying distances, different angles, and under different lighting conditions.

Front 40

Depth perception

Back 40

Our ability to percieve the distance of objects from us.

Front 41

Retinal disparity

Back 41

A binocular depth cue referring to the fact that as the disparity (difference) between the two retinal images of an object increases, the distance of the object from us decreases.

Front 42

Linear perspective

Back 42

A monocular depth cue referring to the fact that as parallel lines recede away from us, they appear to converge- the greater the distance, the more they seem to converge.

Front 43

Interposition

Back 43

A monocular depth cue referring to the fact that if one object partially blocks our view of another, we percieve it as closer to us.