a b c d e f g h i k l m n o p r s t u
v w z
la belle indifférence: The blasé attitude people
with conversion disorder have toward their symptoms.
labelling theory: The general view that serious psychopathology,
such as schizophrenia, is caused by society’s reactions to unusual behaviour.
labile: Easily moved or changed, quickly shifting from one emotion
to another, or easily aroused.
language disorder: Difficulties understanding spoken language (receptive)
or expressing thoughts verbally (expressive).
lanugo: A fine soft hair that develops on the bodies of people
with anorexia nervosa.
latency period: In psychoanalytic theory, the years between ages
six and twelve, during which id impulses play a minor role in motivation.
latent content: In dreams, the presumed true meaning hidden behind
the manifest content.
lateral hypothalamus: A section of the brain that, if lesioned,
is associated with a dramatic loss of appetite.
law of effect: A principle of learning that holds that behaviour
is acquired by virtue of its consequences.
learned helplessness theory: The theory that individuals acquire
passivity and a sense of being unable to act and to control their lives;
this happens through unpleasant experiences and traumas against which
their efforts were ineffective; according to Seligman, this brings on
learning disabilities: General term for learning disorders, communication
disorders, and motor skills disorder.
learning disorders: A set of developmental disorders encompassing
dyslexia, mathematics disorder, and disorder of written expression and
characterized by failure to develop in a specific academic area to the
degree expected by the child’s intellectual level. Not diagnosed if the
disorder is due to a sensory deficit.
learning (behavioural) paradigm: In abnormal psychology, a set
of assumptions that abnormal behaviour is learned in the same way as other
least restrictive alternative: The legal principle according to which
a committed mental patient must be treated in a setting that imposes as
few restrictions as possible on his or her freedom.
lesion: Any localized abnormal structural change in organ or tissue
caused by disease or injury.
libido. See Eros.
Life Change Unit (LCU) score: A score produced by totaling ratings
of the stressfulness of recently experienced life events; high scores
are found to be related to the contraction of a number of physical illnesses.
life-span developmental psychology: The study of changes in people
as they grow from infancy to old age.
lifetime prevalence rate: The proportion of a sample that has ever
had a disorder.
limbic system: The lower parts of the cerebrum, made up of primitive
cortex; controls visceral and bodily changes associated with emotion and
regulates drive-motivated behaviour.
linkage analysis: A technique in genetic research whereby occurrence
of a disorder in a family is evaluated alongside a known genetic marker.
lithium carbonate: A drug useful in treating both mania and depression
in bipolar disorder.
lobotomy: A brain operation in which the nerve pathways between
the frontal lobes of the brain and lower brain structures are cut in hopes
of effecting beneficial behavioural change.
logotherapy: An existential psychotherapy, developed by Viktor
Frankl, aimed at helping the demoralized client restore meaning to life
by placing his or her suffering in a larger spiritual and philosophical
context. The individual assumes responsibility for his or her existence
and for pursuing a meaningful life.
longitudinal studies: Investigation that collects information on
the same individuals repeatedly over time, perhaps over many years, in
an effort to determine how phenomena change. Compare with cross-sectional
loose associations (derailment): In schizophrenia, an aspect of
thought disorder wherein the patient has difficulty sticking to one topic
and drifts off on a train of associations evoked by an idea from the past.
LSD: d-lysergic acid diethylamide, a drug synthesized in 1938 and
discovered by accident to be a hallucinogen in 1943.
Luria–Nebraska test: A battery of neuropsychological tests that
can detect impairment in different parts of the brain.