Introduction to S&P

Question 1

cross-modality matching

Answer 1

The ability to match the intensities of sensations that come from different sensory modalities. This ability enables insight into sensory differences. For example, a listener might adjust the brightness of a light until it matches the loudness of a tone.

Question 1

just noticeable difference (JND) (or difference threshold)

Answer 1

The smallest detectable difference between two stimuli, or the minimum change in a stimulus that enables it to be correctly judged as different from a reference stimulus.

Question 1

Stevens’ power law

Answer 1

A principle describing the relationship between stimulus and resulting sensation that says the magnitude of subjective sensation is proportional to the stimulus magnitude raised to an exponent.

Question 2

period or wavelength

Answer 2

The time (or space) required for one cycle of a repeating waveform.

Question 3

method of adjustment

Answer 3

A method of limits in which the subject controls the change in the stimulus.

Question 3

oculomotor (III) nerves

Answer 3

The third pair of cranial nerves, which innervate all the extrinsic muscles of the eye except the lateral rectus and the superior oblique muscles, and which innervate the elevator muscle of the upper eyelid, the ciliary muscle, and the sphincter muscle of the pupil.

Question 3

sensation

Answer 3

The ability to detect a stimulus and, perhaps, to turn that detection into a private experience.

Question 4

functional magnetic resonance imaging (fMRI)

Answer 4

A variant of magnetic resonance imaging that makes it possible to measure localized patterns of activity in the brain. Activated neurons provoke increased blood flow, which can be quantified by measuring changes in of the response of oxygenated and deoxygenated blood to strong magnetic fields.

Question 6

computed tomography (CT)

Answer 6

An imaging technology that uses X-rays to create images of slices through volumes of material (e.g., the human body).

Question 7

Weber’s law

Answer 7

The principle describing the relationship between stimulus and resulting sensation that says the just noticeable difference (JND) is a constant fraction of the comparison stimulus.

Question 8

vitalism

Answer 8

The idea that there is a force in life that is distinct from physical entities.

Question 10

criterion

Answer 10

In signal detection theory, an internal threshold that is set by the observer. If the internal response is above criterion, the observer gives one response (e.g., “yes, I hear that”). Below criterion, the observer gives another response (e.g., “no, I hear nothing”).

Question 10

supertaster

Answer 10

An individual whose perception of taste sensations is the most intense.

Question 11

absolute threshold

Answer 11

The minimum amount of stimulation necessary for a person to detect a stimulus 50% of the time.

Question 12

two-point touch threshold

Answer 12

The minimum distance at which two stimuli (e.g., two simultaneous touches) are just perceptible as separate.

Question 13

neurotransmitter

Answer 13

A chemical substance used in neuronal communication at synapses.

Question 14

magnitude estimation

Answer 14

A psychophysical method in which the participant assigns values according to perceived magnitudes of the stimuli.

Question 14

sine wave

Answer 14

(1) In hearing, a waveform for which variation as a function of time is a sine function. Also called pure tone. (2) In vision, a pattern for which variation in a property like brightness or color as a function of space is a sine function.

Question 15

method of limits

Answer 15

A psychophysical method in which the particular dimension of a stimulus, or the difference between two stimuli, is varied incrementally until the participant responds differently.

Question 16

psychophysics

Answer 16

The science of defining quantitative relationships between physical and psychological (subjective) events.

Question 18

abducens (VI) nerves

Answer 18

The sixth pair of cranial nerves, which innervate the lateral rectus muscle of each eye.

Question 19

perception

Answer 19

The act of giving meaning to a detected sensation.

Question 20

olfactory (I) nerves

Answer 20

The first pair of cranial nerves. The axons of the olfactory sensory neurons bundle together after passing through the cribriform plate to form the olfactory nerve, which conducts impulses from the olfactory epithelia in the nose to the olfactory bulb.

Question 21

cycles per degree

Answer 21

The number of pairs of dark and bright bars per degree of visual angle.

Question 21

dualism

Answer 21

The idea that the mind has an existence separate from the material world of the body.

Question 22

trochlear (IV) nerves

Answer 22

The fourth pair of cranial nerves, which innervate the superior oblique muscles of the eyeballs.

Question 23

electroencephalography (EEG)

Answer 23

A technique that, using many electrodes on the scalp, measures electrical activity from populations of many neurons in the brain.

Question 24

panpsychism

Answer 24

The idea that the mind exists as a property of all matter—that is, that all matter has consciousness.

Question 24

polysensory

Answer 24

Blending multiple sensory systems.

Question 25

Weber fraction

Answer 25

The constant of proportionality in Weber’s law.

Question 27

optic (II) nerves

Answer 27

The second pair of cranial nerves, which arise from the retina and carry visual information to the thalamus and other parts of the brain.

Question 28

receiver operating characteristic (ROC) curve

Answer 28

In studies of signal detection, the graphical plot of the hit rate as a function of the false-alarm rate. If these are the same, points fall on the diagonal, indicating that the observer cannot tell the difference between the presence and absence of the signal. As the observer’s sensitivity increases, the curve bows upward toward the upper left corner. That point represents a perfect ability to distinguish signal from noise (100% hits, 0% false alarms).

Question 30

Fourier analysis

Answer 30

A mathematical procedure by which any signal can be separated into component sine waves at different frequencies. Combining these sine waves will reproduce the original signal.

Question 31

quale (pl. qualia)

Answer 31

In philosophy, a private conscious experience of sensation or perception.

Question 33

auditory (VIII) nerves

Answer 33

The eighth pair of cranial nerves, which connect the inner ear with the brain, transmitting impulses concerned with hearing and spatial orientation. The auditory nerve is composed of the cochlear nerve branch and the vestibular nerve branch, leading to the alternate name vestibulocochlear nerve.

Question 34

phase

Answer 34

(1) In vision, the relative position of a grating. (2) In hearing, the relative timing of a sine wave.

Question 35

sensitivity

Answer 35

In signal detection theory, a value that defines the ease with which an observer can tell the difference between the presence and absence of a stimulus or the difference between stimulus 1 and stimulus 2.

Question 36

spatial frequency

Answer 36

The number of cycles of a grating per unit of visual angle (usually specified in cycles per degree).

Question 37

blood oxygen level–dependent (BOLD) signal

Answer 37

The ratio of oxygenated to deoxygenated hemoglobin that permits the localization of brain neurons that are most involved in a task.

Question 38

cranial nerves

Answer 38

Twelve pairs of nerves (one for each side of the body) that originate in the brain stem and reach sense organs and muscles through openings in the skull.

Question 40

materialism

Answer 40

The idea that the only thing that exists is matter, and that all things, including the mind and consciousness, are the results of interaction between bits of matter.

Question 41

Fechner’s law

Answer 41

A principle describing the relationship between stimulus and resulting sensation that says the magnitude of subjective sensation increases proportionally to the logarithm of the stimulus intensity.

Question 42

synapse

Answer 42

The junction between neurons that permits information transfer.

Question 43

doctrine of specific nerve energies

Answer 43

A doctrine, formulated by Johannes Müller, stating that the nature of a sensation depends on which sensory fibers are stimulated, not on how fibers are stimulated.

Question 45

method of constant stimuli

Answer 45

A psychophysical method in which many stimuli, ranging from rarely to almost always perceivable (or rarely to almost always perceivably different from a reference stimulus), are presented one at a time. Participants respond to each presentation: “yes/no,” “same/different,” and so on.

Question 46

event-related potential (ERP)

Answer 46

A measure of electrical activity from a subpopulation of neurons in response to particular stimuli that requires averaging many EEG recordings.

Question 47

magnetic resonance imaging (MRI)

Answer 47

An imaging technology that uses the responses of atoms to strong magnetic fields to form images of structures like the brain. The method can be adapted to measure activity in the brain, as well (see functional magnetic resonance imaging).

Question 48

magnetoencephalography (MEG)

Answer 48

A technique, similar to electroencephalography, that measures changes in magnetic activity across populations of many neurons in the brain.

Question 49

positron emission tomography (PET)

Answer 49

An imaging technology that enables us to define locations in the brain where neurons are especially active by measuring the metabolism of brain cells using safe radioactive isotopes.

Question 50

signal detection theory

Answer 50

A psychophysical theory that quantifies the response of an observer to the presentation of a signal in the presence of noise. Measures obtained from a series of presentations are sensitivity (d′) and criterion of the observer.