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UKAHPP The United Kingdom Association of Humanistic Psychology Practitioners. A professional association in the field of Humanistic Psychology, Psychotherapy and Counselling which also accredits individuals in various categories e.g. 'psychotherapist', 'humanistic counsellor', 'gestalt therapist'. It has a complaints procedure, code of ethics and practice.
UKCP The United Kingdom Council for Psychotherapy. An umbrella body that has drawn up its own register of psychotherapists. You cannot register directly with UKCP, but through an organisation like AHPP which is a member of UKCP.
UKRC The register of counsellors that is being set up by the BACP and COSCA ( Scotland).
ultimate cause The remotest cause in a chain of causation; e,g., although a person may have died from a stroke, the ultimate cause might have been his fifty previous years of cigarette smoking, which led to the stroke. See alsoproximate cause.
ultradian rhythm The 90-100 minute biological rhythm that characterizes the alternation of REM and slow-wave periods during sleep and attentiveness while awake. See alsocircadian rhythm.
ultrasound examination (sonogram): an examination that involves bouncing high frequency sound waves off the fetus and transforming the bounced waves into visual images.
ultraviolet light Light whose wavelength is too short to lie within the visible spectrum.
umbilical cord: a tough, cordlike structure connecting the navel of a fetus to the placenta and serving to supply nourishment to, and remove waste from, the fetus.
unconditional positive regard For Carl Rogers, the belief that one is accepted and loved without reservation; an essential component of psychotherapy.
unconditioned reflexSeeunconditioned response.
unconditioned response (UR) In classical conditioning, the response that is elicited without prior training by the unconditioned stimulus (US). See alsoconditioned response (CR), conditioned stimulus (CS), unconditioned stimulus (US).
unconditioned stimulus (US) In classical conditioning, the stimulus that elicits the unconditioned response (UR) and the presentation of which acts as reinforcement. Seeconditioned response (CR), conditioned stimulus (CS), unconditioned response (UR).
unconscious inference A process postulated by Hermann von Helmholtz to explain certain perceptual phenomena such as size constancy. An object is perceived to be in the distance and is therefore unconsciously judged to be larger than warranted by its retinal image. See alsosize constancy.
underlying pathology model An approach to psychopathology which asserts that various overt signs and symptoms are produced by an underlying cause that may be mental or organic or both. The therapist’s objective is to discover and remove the underlying pathology, which will then cause the symptoms to disappear.
underlying structureSeephrase structure.
unemployment: the state of being unemployed; lack of employment.
unilateral neglectSeeneglect syndrome.
unipolar depression a mood disorder marked by feelings of self-blame, sadness, guilt, and apathy.
unique blue The hue corresponding to a wavelength of 445 nanometers, which is perceived as containing no red or green.
unique green The hue corresponding to a wavelength of 500 nanometers, which is perceived as containing no blue or yellow.
unique yellow The hue corresponding to a wavelength of 570 nanometers, which is perceived as containing no red or green.
universal structure The specific syntactic organization that some observers believe is preprogrammed in human language.
universality thesis The hypothesis, originated by Darwin , that facial expressions worldwide look identical, are perceived identically, and express identical emotions.
unreinforced trial In classical conditioning, a trial in which the conditioned stimulus (CS) is presented without the unconditioned stimulus (US).
uterus: a hollow, muscular organ of female mammals in which the ovum is deposited and the embryo and fetus are developed; womb.
valid: well-grounded on principles or evidence; able to withstand criticism or objection, as an argument; sound; in testing, describes a test that measures what it purports to measure.
validity coefficient The correlation between test scores and an independent measure of the trait (for example, scores on a test of "college potential" and the GPAs the test takers earn when they get to college). Such a correlation is obtained in order to evaluate the extent to which a test measures the intended attribute or trait.
validity The extent to which a test measures what it is supposed to measure. Values Enduring beliefs about important life goals that transcend specific situations.
variability The degree to which scores in a frequency distribution depart from the central value.
variable: anything changeable; especially, a quality or quantity that varies or may vary.
variance (V) A measure of the variability of a frequency distribution. It is computed by finding the difference between each score and the mean (M), squaring the result, adding all these squared deviations, and dividing the sum by the number of cases. If N is the number of scores, then V = sum of (score - M)²/ N.
vasoconstriction The constriction of blood vessels brought on by activation of the sympathetic division of the autonomic nervous system. Vasoconstriction occurs in emergencies, when blood is diverted from the skin and internal organs to the muscles. It is also crucial in mammalian thermoregulation; in response to excessive cold, blood is diverted from the skin to reduce heat loss.
vasodilatation The dilating of blood vessels brought on by activation of the parasympathetic division of the autonomic nervous system. Vasodilatation is one component of mammalian thermoregulation; in response to excessive heat, warm blood flows to the body’s surface and results in heat loss by radiation.
vasopressin (antidiuretic hormone) A hormone manufactured in the hypothalamus and secreted by the pituitary that elevates blood pressure by producing vasoconstriction and instructs the kidneys to conserve water instead of excreting it.
Vector Mathematically speaking, a vector is a quantity that has a magnitude and a direction. Graphically it is drawn as a line whose length represents the magnitude and whose orientation in space represents a direction. A vector can also be a form of notation for describing a pattern of numbers, i.e. height, weight, and IQ.
vegetative signs Physical manifestations that often accompany major depression, such as loss of appetite and weight loss, weakness, fatigue, poor bowel functioning, sleep disorders (most often early-morning awakenings), and loss of interest in sex.
ventral tegmental area (VTA) A region in the midbrain containing dopamine-releasing pathways thought to be involved in reward.
ventromedial region of the hypothalamusSeelateral hypothalamus.
vesicles The tiny sacs in the presynaptic neuron that contain neurotransmitters.
vestibular senses A set of receptors that provide information about the orientation and movements of the head, located in the semicircular canals and the vestibular sacs of the inner ear.
vestibules Bony cavities on either side of the head that contain the structures of the inner ear.
viable fetus: a fetus that is able to live outside of the uterus.
vicarious distress The distress produced by witnessing another’s suffering. Like empathic concern, it motivates one to help others, but is less reliable. See alsoempathic concern.
vicarious reinforcement According to social learning theorists, a form of reinforcement that occurs when someone watches a model being rewarded or punished.
villi: any of numerous hairlike or fingerlike vascular processes on certain mucous membranes of the body, as of the small intestine, serving to secrete mucus, absorb fats, and so on; or of the chorion in the mammalian placenta, serving in the exchange of food materials, and so on between the mother and the fetus.
viruses: noncellular, microscopic particles that replicate themselves within invaded cells.
visible spectrum The range of wavelengths to which our visual system can respond, extending from about 400 (the wavelength of the color violet) to 750 nanometers (the wavelength of the color reddish orange).
visual cliff A device for assessing depth perception, often used with human infants; it consists of a glass surface that extends from a shallow side over an apparently deep side (the cliff).
visual pigments Light-sensitive chemicals within the rods and cones of the eye.
visual search task A test in which research participants are briefly presented a display and must indicate whether a certain target is present or absent.
visual segregationSeeperceptual parsing.
volume receptors Receptors that help regulate thirst by indicating the total volume of fluids in the body. See alsoosmoreceptors.
volunteer bias: an error in research that occurs when a sample of volunteers is not representative of the general population.
vomeronasal organ A distinct set of receptor cells in the nose that are specialized for the detection of pheromones.
wavelength The distance between the crests of two successive waves and the major determinant of pitch (for sound) and hue (for light).
Weber fraction In Weber’s law, the fraction given by the change in stimulus intensity (deltaI) divided by the standard intensity (I) required to produce a just-noticeable difference: I/I = C.
Weber’s law The observation that the size of the difference threshold is proportional to the intensity of the standard stimulus.
Wechsler Intelligence Scale for Children (WISC): a popular IQ test.
well-defined problems Problems for which there is a clear-cut way of deciding whether a proposed solution is correct. This contrasts with ill-defined problems, for which it is unclear what a correct solution might be.
Wernicke’s area A brain area adjacent to the auditory projection area, damage to which leads to deficits in understanding word meaning.
what system The system of visual circuits and pathways leading from the visual cortex to the temporal lobe, especially involved in object identification.
where system The system of visual circuits and pathways leading from the visual cortex to the parietal lobe, especially involved in the spatial localization of objects and in the coordination of movements.
white matter Whitish appearing patches and paths in the brain composed of myelinated axons.
widow: a woman who has outlived the man to whom she was married at the time of his death; especially, such a woman who has not remarried.
widower: a man who has outlived the woman to whom he was married at the time of her death; especially, such a man who has not remarried.
widowhood: the disruption of marriage due to the death of the spouse.
wisdom: expert and practical knowledge based on life experience.
wish fulfillment in dreamsSeeFreud’s theory of dreams.
withdrawal effectsSeeopponent-process theory of motivation.
withdrawal symptoms A consequence of drug addiction that occurs when the drug is withheld. These effects tend to be the opposite of those produced by the drug itself.
within-family differences In research on the genetics of behavior, a term often used to refer to the role of environment. It describes differences in the environment (e.g., different schools) of individual family members. For most personality attributes, these seem to be more important than between-family differences. See alsobetween-family differences.
within-group heritability The extent to which variation within groups (e.g., among U.S. whites) is attributable to genetic factors. See alsobetween-group heritability, heritability ratio (H).
workaholism: addiction to work.
working memory A part of the memory system that is currently activated but has relatively little cognitive capacity.
X-chromosome One of the two sex chromosomes containing the genes that determine whether a given animal will be male or female. In mammalian females, both sex chromosomes are X-chromosomes; in mammalian males, there is one X-chromosome and one Y-chromosome.
Y-chromosomeSeeX-chromosome.
Young-Helmholtz theory A theory of color vision which holds that each of the three receptor types (short-wave, medium-wave, and long-wave) gives rise to the experience of one basic color (blue, green, or red).
zero stimulus In signal detection theory, an ideal state in which, in some sensory domain, the participant is perceiving nothing. This state is impossible, because background noise is always present.
Zipf’s law The fact that words that occur frequently in a language tend to be relatively short.
zona pellucida: the gelatinous covering of the egg.
z-scoreSeestandard score (z-score).
zygote The fertilized ovum resulting from the union of a sperm and an ovum (egg cell) in sexual reproduction, a cell formed by the union of male and female gametes; fertilized egg cell before cleavage.