V

V 1 Variable stimulus (also v). 2 Variance. 3 Photopic luminosity coefficient

V1, V2 ...V5 The V stands for vision and the number denotes a neuroanatomically distinct area of the visual system. See following for details

V1 The area of the occipital region also known as the primary visual cortex. Information arrives here from the lateral geniculate nucleus and is transmitted to other visual areas, primarily V2, V4, and V5, through different neural streams. The dorsal stream, often oversimplified as the 'where' pathway, goes through V2 to V5 and to the inferior parietal lobule and is linked with object location, motion and the processing of visual information for controlling movement. The ventral stream, somewhat simplistically called the 'what' pathway, also carries information to V2 then to V4 and the inferior temporal lobe and is associated with form and object recognition and long-term memory. V1 is the evolutionarily oldest visual area, the most extensively studied and the best understood. It is keyed to processing information about objects, both stationary and moving and carries out basic pattern recognition functions. In all animals with a V1, there is a clear correspondence between a specific spot in the visual field and a specific cortical location. Also known by a host of other names including retinotectal projection area, retinal projection area, and (sometimes ambiguously) visual projection area.

V2 An area of the occipital region that lies adjacent and anterior to V1. It receives inputs directly from V1 and sends information on to V3, V4, and V5. It also has feedback loops to V1. Anatomically it is split into four quadrants which function visuotopically (see retinotopic representation) to provide a full representation of the external, visual world.

V3 A part of the visual cortex. It is less well defined anatomically than other areas and is the only visual area that V1 does not project to. It lies just in front of V2, from which it receives inputs. It appears to have color sensitive neurons and may play a role in perception of global motion, a fact that suggests that it may have, like V2, a full representation of the visual world.

V4 An area of visual cortex that lies in the occipitotemporal cortex, anterior to V2. It receives inputs from V1 and V2 and processes information about color, spatial orientation, spatial frequency and geometric shapes. Most of what is known about it comes from work with macaques.

V5 The part of the visual cortex located in the extrastiate cortex of the medial temporal area. Projections come from V1, V2 and, probably, from V3; it transmits information to a wide variety of brain regions through a complex array of pathways. Its functions appear complex although there is compelling evidence for a primary role in processing movement. Lesions here cause a motion agnosia.

V¹ Scotopic luminosity coefficient. var., V¹.

v 1 Variable stimulus (also V). 2 Volume. 3 Volt.

vaccinate To produce immunity to a disease by inoculation.

vacuum activity An ethological term referring to the occurrence of a fixed action pattern in the absence of its usual external stimulus (or releaser). The assumption is that action-specific energy builds up, breaks through the inhibit

T

T 1 Temperature 2 Time.

sTR In Hull's notational system, reaction time. Elsewhere RT is used.

t 1 A symbol used for denoting the ratio between a statistic and the measure of its standard error. See t test and t *distribution, 2 Abbreviation for time.

tabes 1 Generally, any progressive degeneration found in a chronic disease. 2 More specifically, degeneration of the posterior columns of the spinal cord. syn., tabes dorsallis

table A collection of scores or other data arranged in tabular form.

taboo 1 Any banned or prohibited act, object or behaviour. 2 The act of prohibition. The term comes from the Polynesian tabu, meaning sacred, inviolable, and was originally associated with objects set aside for religious practices and customs and forbidden for general use. Contemporary usage is much broader. adj., taboo, tabooed.

tabula rasa - Latin meaning blank tablet. The term refers to the philosophical view that humans came into this world unencumbered (and unassisted) by particular innate ideas. Espoused strongly by the early British empiricists, this view formed the basis of the theory that learning and experience are the critical factors in the human condition: the environment writes its message on the pristine mind.

tach - Laboratory slang for tachistoscope.

tachistoscope - An instrument that presents visual materials under conditions of very brief exposures. A sophisticated variety may have up to three or four separate screens (the images from which may be superimposed upon each other in any combination), an extremely precise timing system that can present materials for extremely short durations (less than 1msec.) and illumination controls to adjust the brightness of the display. Also called T-Scope, tach.

tach(y) - Combining form meaning rapid, swift, fast.

tachycardia A general term for any abnormally rapid heart action

tachylalia - Unusually rapid speech.

tachyphasia - Very rapid or highly voluble speaking.

tachyphrenia - Rapid mental functioning.

tachyphylaxis - Rapid, acute development of tolerance to a particular drug resulting from frequent, repeated administration. See drug *tolerance. syn., acute tolerance.

tacit - 1 unspoken or silent. 2 Inferred or understood. 3 Unconscious. See also implicit.

tacit knowledge - knowledge, tacit

tact - One of the categories of verbal behavior proposed by Skinner in his analysis of language. Tacting is verbal behavior that is under the control of its antecedents and makes contact with the external world. Naming is a classic tact. See autoclitic and mand.

tact- - Combining form meaning touch.

tactic - taxis

tactile - Pertaining or relating to touch, tactual. Some use it as a synonym of haptic, but see that term for a distinction.

tactile agnosia - agnosia, tactile.

tactile receptors - Meissner's corpuscles, Merkel's discs.

R

R a sometimes confusingly polyfunctional abbreviation. To wit: 1 Response, as in the common shorthand S-R for stimulus-response. 2 Stimulus from the German word Reiz. The confusion once produced by these two conflicting uses is less these days as the latter use is now rare. 3 multiple *correlation coefficient 4 a general reasoning factor hypothesized by some to be a primary mental ability

R_c An infrequent abbreviation for conditioned response; CR is more common.

R_G In Hull's theory, any goal-attaining response, e.g. eating, drinking.

R_1,2,3,...nmultiple correlation coefficient

RP The probability of a response. This abbreviation is used little, p being the more common notation for probability, with the response under consideration usually being clear from context.

Ru An infrequent abbreviation for unconditioned response.; UR and UCR are encountered more often.

r 1 The product-moment *correlation coefficient: see also Rxy. 2 In Hull's theory, the efferent reaction leading to an overt response. Also called a pure-stimulus *act.

rbis The biserial *correlation coefficient.

rG In Hull's theory, a fractional antedating goal response.

r12.34 partial *correlation coefficient. It denotes the correlation of the variables to the left of the point (here, 1 and 2) after the influences of those to the right (here, 3 and 4) have been removed.

r2 The square of the value of a product-moment *correlation coefficient. It provides an estimate of the proportion of the variance in the data that can be attributed to the relationship. Occasionally written r-squared.

rt The tetrachoric correlation coefficient. Also denoted as rtet.

rtet Rt.

rxy The product-moment *correlation with the variables (x and y) that enter into its computation denoted.

race A term born in anthropological innocence and meant simply to designate the major subdivisions of Homo sapiens. A race was defined as any relatively large division of persons that could be distinguished from others on the basis of inherited physical characteristics such as skin pigmentation, blood groups, hair textures and the like. In actual practice, it is nearly impossible to classify or distinguish individual persons by such physical characteristics, for no specific set of them truly constitutes criterial features. If the concept has any residual meaning in this respect, it is only when the relative frequency of occurrence of physical traits in a population is assessed. For example, there are many blacks with 'lighter skins' than many 'whites', so skin color can not serve as a definitive criterion for any arbitrarily selected individual. However, among the population of persons who identify themselves as 'black' there will be a higher relative frequency of dark-skinned individuals than among the population of those who identify themselves as 'white'. Since the key criterion here is identify themselves as, it is clear that the working definition of race is one that is dependent on a social-cultural-political identification and not one that can be unambiguously determined by genetic classification. See also race differences.

S

S - Abbreviation for 1 Stimulus; See S⁺, S^-, S-R, S^∆, S^D 2 Subject. 3 In some older writings, sensation. This last use is usually restricted to instances in which R is used for stimulus; see REIZ. 4 In psychophysics, standard.

'S' - the pseudonym (his real name was Soloman Shereshevskii) of a mnemonist studied by Alexander Luria. A man of average intelligence, S's seemingly inexhaustible memory capacity was aided by his use of a variety of mnemonic devices and coding schemes, a remarkable ability to form associations between things and a most unusual and bizarrely developed synaesthesia.

S^c, S_c conditioned stimulus, CS is preferred.

S^D drive stimulus

S^D abbreviation for discriminative stimulus. In operant-conditioning studies, S^D denotes the stimulus in the presence of which responses are reinforced and S^∆ the stimulus in the presence of which responses go unreinforced. Compare with S⁺ and  S^-.

S^∆  See the discussion under S^D

S⁺, S^-  In discrimination-learning experiments, the positive stimulus (responses to which are reinforced)is generally denoted as S⁺ and the negative stimulus (responses to which go unreinforced) by S^- In this sense S⁺ = S^D and S^-= S^∆

S^c, S^c Unconditioned stimulus, UC and UCS are more common.

s 1 sensation 2 the standard deviation in a data sample 3 any variable stimulus. This use is generally restricted to the area of psychophysics

s^g a fractional goal stimulus

s² variance

s_x standard error of the mean

SAC stimulus as coded

saccade a quick eye movement, a jump of the eyes from one fixation point to another. Saccadic movements are seen most clearly during reading and the scanning of visual displays. The eye was once thought to be functionally blind during a saccade: it is now known that some vision does occur although fine details are not picked up. Saccades toward an object are sometimes termed prosaccades, those away, antisaccades. They may be either voluntary or automatic. vb., saccade.

saccadic disymmetria - ocular disymmetria

saccule - the smaller of the two vestibular sacs in the inner ear. Like the utricle, it is approximately round in shape and has a layer of receptors in its 'floor' that respond to changes in the orientation of the head.

sacral pertaining to the area around and including the sacrum

sacral division  a division of the autonomic nervous system

sacred - characterizing aspects of a society that are treated with great respect. They may be physical objects (i.e. a cross, an ark), or they may be spiritual, supernatural, or even emerging ideas derived from  the shared values of a society (e.g. patriotism). In the social sciences the term encompasses more than the religious or the divine; in fact, it can be taken to refer to anything which is not to be taken frivolously.

E

E A multifunctional abbreviation used for: 1 Experimenter. 2 Experimental group. 3 Energy. 4 Error. 5 Within the theory of learning of C.L. Hull it is found in a veritable 'alphabet soup' of symbols used to refer various theoretical constructs. A few of the more common are: sEr = excitatory potential; sEr = reaction potential (from generalization); sEr = effective reaction potential. The interested reader is referred to any of the older (1950s) standard texts of learning theory for fuller explanation of these and others; they are rarely used in contemporary work in learnig
-e- Alternative spelling of -ae- used in terms of Greek and Latin origin.
e² - In studies of genetic influences, the portion of the variance that is attributable to environmental factors. An example would be differences in achievement by two identical twins due to each having different teachers in school. Sometimes capitalized. see environmentality
ear - Most generally, the organ of hearing. Three anatomical divisions make up the whole organ. The outer ear consists of the pinna (what is, in general parlance, called the ear) and the external auditory meatus (or canal) up to the tympanic membrane (or eardrum). The middles ear contains the ossicles, the three bones which transmit vibrations of the tympanic membrane to the oval window on the cochlea. The middle ear is also connected to the pharynx via the Eustachian tube, which serves to equalize air pressure. The inner ear consists of the cochlea and the semicircular canals. Within the cochlea are the receptor cells for audition.
eardrum tympanic membrane
early 1 In developmental psychology, referencing a time somewhere toward the first few years of life. Exactly when early ends is not always clear. In research on language development, early can be anywhere from 5 years to puberty; in memory research 'early' usually refers to recall of events before the age of 3; in emotional development and personality formation usage depends on the theoretical stance of the writer and can mean anything from 5 years of age to adulthood. Note that late suffers from a similar pattern of ambiguous usage with reference to events that occur after some number of years of life have passed. In perception and cognitive psychology, before something else as in early-selection-model.
early Alzheimer's disease - mild cognitive impairment
Early Learning Advisor - A computerized assessment and planning system based on the concept of the zone of proximal development, used by some teachers to assess students and select appropriate educational goals and techniques in reading or writing. When the system is applied to the acquisition of reading and writing skills, it is called the early literacy advisor.
early selection model - a model of selective attention that assumes that items are selected for attention early in processing, soon after the sensory input has been received. Compare with late-selection-model where the assumption is that attention is not focused on the item until later in processing, after it has been identified and categorizedThe distinction between these two is not as clear as the proponents of each had hoped and, indeed, both kinds of processing take place depending on a myriad of factors.

A

A 1 Amplitude (2). 2 Albedo.
a-, an- Prefix meaning away from or opposite to.
abasement H. Murray's term for a need to surrender one's self or will to another, to atone for real or imagined shortcomings
abasia Inability to walk owing to impairment in motor coordination
abdominal reflex Contraction of the abdominal muscles when the overlying skin
abducens 1 The Vith cranial nerve. It innervates the external rectus muscle in the eye, which functions to rotate the eyeball inward. Also called the abducent nerve. 2 Pertaining to movement away from the central plane of the body. See abduction. 
abducent nerve abducens
abduction 1 Lateral movement of a limb away from the median plane of the body. Compare with adduction. 2 C.S. Peirce's term for the cognitive process wherebyhypotheses are generated on the basis of some known facts. Abduction, in Pierce's terms, was a fundamental component of creative thought. 
abductor - a muscle which, upon contraction, moves a limb away from the body. Compare with adductor
aberration - The act of wandering or straying from the normal course. The term enjoys wide currency and is used of the behavior of an intact organisms as well as for biological structures, physical systems, instruments, etc.
aberration, chromatic - Unequal refraction of light of different wavelengths as it passes through a lens, producing a coloured image.
aberration, mental - a nontechnical term used loosely for any mental disorder
aberration, spherical - distortions of a light wave passing through a lens produced either by the natural curvature of the lens of the irregularities in the curvature of the lens
ABI - acquired brain injury
abient - characterizing movement away from something, ant. adient.
ability - the qualities, power, competence, faculties, proficiencies, dexterities, talents, etc. that enable one to perform a specified feat in a particular time. The essence of the term is that the person can perform this task now, no further training is needed. The main distinction thus is between ability and aptitude. Ability is an individual's potential to perform; aptitude is an individual's potential for performance, or the possibility of the individual to be trained up to a specified level of ability. Intelligence tests, for example, are ability tests.
abiotic - Not compatible with life.
ablation - Removal of part of an organ. Usually refers to surgical removal. When the full organ or structure is removed, the term exterpation is generally used
Abney's Effect a perceptual phenomenon experienced when a large room is suddenly illuminated. Rather than appearing all at once, the light seems to come on first in the center of the patch and then spread to the edges. When extinguished, the edges disappear first, the center last.