data-driven processing Information flowing from our sense organs to the brain. 4
deep processing (elaborative rehearsal) The mental activity that facilitates the transfer of information from short-term to long-term memory storage by emphasizing the meaning of the stimulus. 7
defense mechanism According to Freud, a mental strategy that blocks the harmful id impulse while reducing anxiety. 13
delta sleep The deepest stage of sleep when delta waves occupy more than 5O percent of a sleeper’s EEG. 5
delta waves Very slow brain waves that predominate during deep sleep. 5
delusions Irrational beliefs that are held despite overwhelming evidence to the contrary. 15
demand characteristics In an experiment, any clues felt by the subjects about the responses they think the researcher wants them to make. 2
dendrites The short, branched extensions of a neuron that usually carry neural impulses toward the cell body. 3
denial According to Freud, a defense mechanism that involves a refusal to acknowledge some threat. 13
dependent variable A factor that is expected to change when the independent variable is manipulated. 2
depolarized Decreased electrical imbalance associated with the resting state. 3
depressants Drugs that suppress central nervous system activity, causing feelings of relaxation or reduced anxiety. 5
depressive disorders A mood disorder in which a sad, discouraged mood is the major symptom. 15
depth perception The ability to see the world in three dimensions and tell how far away an object is. 4
descriptive statistics Statistical methods used to summarize a vast amount of data in forms that are brief and easy to understand. 2
developmental psychologists Researchers who try to describe and explain the systematic changes that occur throughout the life cycle. 1
developmental psychology The study of progressive changes in human traits and abilities that occur throughout the life span. 9
dialectic operations stage According to Klaus Riegel, the highest stage of intellectual functioning, whereby mature thinkers debate a deep moral, religious, or philosophical issue. 9
diathesis–stress model A theory that the interaction of factors such as biological predisposition combined with life stress may cause schizophrenia. 15
dichotic listening A technique, developed by E. C. Cherry, involving the simultaneous input of different information into each ear; used to study the “cocktail party phenomenon.” 7
dichromats People who are partially color-blind because of the lack or loss of one of the three forms of iodopsin normally found in the cones. 4
direct perspective A theory of perception that sensory data presented to the eye are passed to the brain, which automatically structures the data into a meaningful whole. 4
direct tests Tests that require conscious awareness, like recall and recognition. 7
discrimination The behavioral expression of prejudice. 17
discrimination training A procedure used to teach an animal to respond only to a specific stimulus by presenting similar stimuli that will not elicit a reward. 6
discriminative stimulus The stimulus that elicits the reward in discrimination training. 6
dispersion The degree of scatter among the individual numbers of a set of numbers. 2
displacement According to Freud, a defense mechanism that involves the transfer of unacceptable feelings from their appropriate target to a much “safer” one. 13
dissociation A split in consciousness whereby certain thoughts, feelings, and behaviors operate independently from others; one theory of what happens in hypnosis. 5
dissociative amnesia The partial or total forgetting of past experiences after some stressful event. 15
dissociative disorders Psychological disorders that involve the splitting off of a part of the personality so that personal memory or identity is disturbed. 15
dissociative fugue A psychological disorder in which the victims walk away from their homes and their identities for a period of hours, days, months, or even years. 15
dissociative identity disorder (multiple-personality disorder) A psychological disorder in which a person (more often a female) evolves two or more separate personalities, each well defined. 15
divergent thinking The ability to generate many different answers to a question. 8
door-in-the-face technique A compliance strategy in which a smaller counter request is made in response to a refusal to a larger request. 18
dopamine A monoamine (neurotransmitter) found in the limbic system, cerebellum, and basal ganglia of the brain. It plays a critical role in thought disorders and movement disorders. 3
double-blind technique A procedure in which neither the experimenter nor the subjects know who has been assigned to the experimental group or who is acting as a control. 2
dream analysis A psychoanalytic technique in which the hidden meaning of a dream can be brought to light, and unconscious wishes, fantasies, and conflicts can be explored. 16
drive-reduction theory A theory of motivation developed by behaviorist Clark Hull and others stating that biological needs are the basic motivator of action. 11
drug therapy The treatment of psychological disorders through the administration of drugs. 16
dysthymic disorder (dysthymia) A chronic form of depression that lasts for years at a time. 15