a b c d e f g h i k l m n o p r s t u
v w z
tachycardia: A racing of the heart, often associated with high
levels of anxiety.
tardive dyskinesia: A muscular disturbance of older patients who
have taken phenothiazines for a very long time, marked by involuntary
lip smacking and chin wagging.
Taylor Manifest Anxiety Scale: Fifty items drawn from the MMPI,
used as a self-report questionnaire to assess anxiety.
temporal lobe: A large area of each cerebral hemisphere situated
below the lateral sulcus and in front of the occipital lobe; contains
primary auditory projection and association areas and general association
tertiary prevention: See prevention.
testes: Male reproductive glands or gonads; the site where sperm
develop and are stored.
testosterone: Male sex hormone secreted by the testes that is
responsible for the development of sex characteristics, such as enlargement
of the testes and growth of facial hair.
test-retest reliability: See reliability.
tetrahydrocannabinol (THC): The major active chemical in marijuana
T-group: See sensitivity training group.
thalamus: A major brain relay station consisting of two egg-shaped
lobes located in the diencephalon; it receives impulses from all sensory
areas except the olfactory and transmits them to the cerebrum.
Thanatos: In psychoanalytic theory, the death instinct; with Eros,
the two basic instincts within the id.
Thematic Apperception Test (TAT): A projective test consisting
of a set of black-and-white pictures reproduced on cards, each depicting
a potentially emotion-laden situation. The examinee, presented with the
cards one at a time, is instructed to make up a story about each situation.
theory: A formally stated and coherent set of propositions that
purport to explain a range of phenomena, order them in a logical way,
and suggest what additional information might be gleaned under certain
therapeutic community: A concept in mental health care that views
the total environment as contributing to prevention or treatment.
thiamine: One of the complex of B vitamins.
third-variable problem: The difficulty in the correlational method
of research whereby the relationship between two variables may be attributable
to a third factor.
Thorazine: Trade name for chlorpromazine, one of the antipsychotic
drugs and a member of the phenothiazine group.
thought disorder: A symptom of schizophrenia, evidenced by problems
such as incoherence, loose associations, poverty of speech, and poverty
of content of speech.
thought listing: A cognitive assessment technique that involves
a person writing down his or her thoughts upon experiencing an event,
such as taking a test or meeting a person.
thyroid gland: An endocrine structure whose two lobes are located
on either side of the windpipe; it secretes thyroxin.
time-of-measurement effects: A possible confound in longitudinal
studies whereby conditions at a particular point in time can have a specific
effect on a variable that is being studied over time.
time-out: An operant conditioning punishment procedure in which,
after bad behaviour, the person is temporarily removed from a setting
where reinforcers can be obtained and placed in a less desirable setting,
for example, in a boring room.
token economy: A behaviour therapy procedure, based on operant
conditioning principles, in which institutionalized patients are given
scrip rewards, such as poker chips, for socially constructive behaviour.
The tokens can be exchanged for desirable items and activities such as
cigarettes and extra time away from the ward.
tolerance: A physiological process in which greater and greater
amounts of an addictive drug are required to produce the same effect.
See substance dependence.
trait: A somatic characteristic or an enduring psychological predisposition
to respond in a particular way, distinguishing one individual from another.
tranquilizer: A drug that reduces anxiety and agitation, such
as Valium. See anxiolytics.
transference: The venting of the patientís emotions, either positive
or negative, by treating the psychoanalyst as the symbolic representative
of someone important in the past. An example is the patientís becoming
angry with the psychoanalyst to release emotions actually felt toward
his or her father.
transference neurosis: A crucial phase of psychoanalysis during
which the patient reacts emotionally toward the psychoanalyst, treating
the analyst as a parent and reliving childhood experiences in his or her
presence. It enables both psychoanalyst and patient to examine hitherto
repressed conflicts in the light of present-day reality.
transsexual: A person who believes he or she is opposite in sex
to his or her biological endowment; sex-reassignment surgery is frequently
transvestic fetishism: The practice of dressing in the clothing
of the opposite sex, for the purpose of sexual arousal.
trauma: A severe physical injury or wound to the body caused by
an external force, or a psychological shock having a lasting effect on
traumatic disease: An illness produced by external assault, such
as poison, a blow, or stress; for example, a broken leg.
tremor: An involuntary quivering of voluntary muscle, usually
limited to small musculature of particular areas.
trepanning: The act of making a surgical opening in a living skull.
This act was sometimes performed because of the belief that it would allow
evil spirits to leave the body.
triadic reciprocality: The influence of cognition and behaviour
on each other through the relationships among thinking, behaviour, and
tricyclic drugs: A group of antidepressants with molecular structures
characterized by three fused rings. Tricyclics are known to interfere
with the reuptake of norepinephrine and serotonin by a neuron after it
trisomy: A condition wherein there are three rather than the usual
pair of homologous chromosomes within the cell nucleus.
tumescence: The flow of blood into the genitals.
tumour (neoplasm): Abnormal growth that when located in the brain
can either be malignant and directly destroy brain tissue or be benign
and disrupt functioning by increasing intra-cranial pressure.
twin method: Research strategy in behaviour genetics in which
concordance rates of monozygotic and dizygotic twins are compared.
two-factor theory: Mowrerís theory of avoidance learning according
to which (1) fear is attached to a neutral stimulus by pairing it with
a noxious unconditioned stimulus, and (2) a person learns to escape the
fear elicited by the conditioned stimulus, thereby avoiding the unconditioned
stimulus. See fear-drive.
Type A behaviour pattern: One of two contrasting psychological
patterns revealed through studies seeking the cause of coronary heart
disease. Type A people are competitive, rushed, hostile, and over-committed
to their work, and are believed to be at heightened risk for heart disease.
Those who meet the other pattern, Type B people, are more relaxed and
relatively free of pressure.