Absolute threshold
The minimum stimulation needed to detect a particular stimulus 50 percent of the time
Accommodation(Developmental)
Adapting one's current understandings (schemas) to incorporate new information
Accommodation(Biological)
The process by which the eye's lens changes shape to focus the image of near objects on the retina
Acetylcholine (ACh)
A neurotransmitter that, among its functions, triggers muscle contraction
Achievement motivation
A desire for significant accomplishment: for mastery of things, people, or ideas; for attaining a high standard
Achievement test
A test designed to assess what a person has learned
Acoustic encoding
The encoding of sounds, especially the sound of words
Acquisition
The initial stage in classical conditioning; the phase associating a neutral stimulus with an unconditioned stimulus so that the neutral stimulus comes to elicit a conditioned response. In operant conditioning, the strengthening of a reinforced response
Action potential
A neural impulse; a brief electrical charge that travels down an axon. The action potential is generated by the movement of positively charged atoms in and out of channels in the axon's membrane
Active listening
Empathetic listening in which the listener echoes, restates, and clarifies. A feature of Rogers client-centered therapy
Acuity
The sharpness of vision
Adaptation-level phenomenon
Our tendency to form judgments (of sounds, of lights, of income) relative to a "neutral" level defined by our prior experience
Adolescence
The transition period from childhood to adulthood, extending from puberty to independence
Adrenal glands
A pair of endocrine glands just above the kidneys. The adrenals secrete the hormones epinephrine (adrenaline) and nor epinephrine (noradrenaline), which help to arouse the body in times of stress
Aerobic exercise
Sustained exercise that increases heart and lung fitness; may also alleviate depression and anxiety
Aggression
And physical or verbal behavior intended to hurt or destroy
Algorithm
A methodical, logical rule or procedure that guarantees solving a particular problem. Contrasts with the usually speedier- but also more error-prone use of heuristics
Alpha waves
The relatively slow brain waves of a relaxed, awake state
Altruism
Unselfish regard for the welfare of others
Alzheimer's disease
A progressive and irreversible brain disorder characterized by gradual deterioration of memory, reasoning, language, and finally, physical functioning
Amnesia
The loss of memory
Amphetamines
Drugs that stimulate neural activity, causing speeded up body functions and associated energy and mood changes
Amygdala
Two almond-shaped neural clusters that are components of the limbic system and are linked to emotion
Anorexia nervosa
An eating disorder in which a normal-weight person (usually and adolescent female) diets and becomes significantly (15 percent or more) underweight, yet, still feeling fat, continues to starve
Antisocial personality disorder
A personality disorder in which the person (usually a man) exhibits a lack of conscience for wrongdoing, even toward friends and family members. May be aggressive and ruthless or a clever con artist
Anxiety disorders
Psychological disorders characterized by distressing, persistent anxiety or maladaptive behaviors that reduce anxiety
Aphasia
Impairment of language, usually caused by left hemisphere damage either to Broca's area (impairing speaking) or to Wernike's area (impairing understanding)
Applied research
Scientific study that aims to solve practical problems
Aptitude test
A test designed to predict a person's future performance, aptitude is the capacity to learn
Artificial intelligence (AI)
Science of designing and programming computer systems to do intelligent things and to stimulate human thought process such as intuitive reasoning, learning, and understanding language. Includes practical implications (chess playing, industrial robots, exp
Assimilation
Interpreting one's new experience in terms of one's existing schemas
Association areas
Areas of cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking
Associative learning
Learning that certain events occur together. The events may be two stimuli (as in classical conditioning) or a response and its consequences (as in operant conditioning)
Attachment
An emotional tie with another person; shown in young children by their seeking closeness to the caregiver and showing distress on separation
Attitude
A belief and feeling that predisposes one to respond in a particular way to objects, people, and events
Attribution theory
The theory that we tend to give a casual explanation for someone's behavior, often by crediting either the situation or the person's disposition
Audition
The sense of hearing
Automatic processing
Unconscious encoding of incidental information, such as space, time, and frequency, and of well-learned information, such as word meanings
Autonomic nervous system
The part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms
Availability heuristic
Estimating the likelihood of events based on their availability in memory; if instances come readily to mind (perhaps because of their vividness), we presume such events are common
Aversive conditioning
A type of counterconditioning that associates an unpleasant state (such as nausea) with an unwanted behavior (such as drinking alcohol)
Axon
The extension of a neuron, ending in branching terminal fibers, through which messages are sent to other neurons or to muscles or glands
Babbling stage
Beginning at 3 to 4 months, the stage of speech development in which the infant spontaneously utters various sounds at first unrelated to the household language
Barbiturates
Drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgment
Basal metabolic rate
The body's resting rate of energy expenditure
Basic research
Pure science that aims to increase the scientific knowledge base
Basic trust
According to Erik Erikson, a sense that the world is predictable and trustworthy; said to be formed during infancy by appropriate experiences with responsive caregivers
Behavior genetics
The study of the relative power and limits of genetic and environmental influences on behavior
Behavior therapy
Therapy that applies learning principles to the elimination of unwanted behaviors
Behavioral medicine
An interdisciplinary field that integrates behavioral and medical knowledge and applies that knowledge to health and disease
Behaviorism
The view that psychology (1) should be an objective science that (2) studies behavior without reference to mental processes. Most research psychologists today agree with (1) but not (2)
Belief bias
The tendency for one's preexisting beliefs to distort logical reasoning, sometimes by making invalid conclusions seem valid, or valid conclusions seem invalid
Belief perseverance
Clinging to one's initial conceptions after the basis on which they formed has been discredited
Binocular cues
Depth cues, such as retinal disparity and convergence, that depend on the use of two eyes
Bio-psycho-social perspective
A contemporary perspective which assumes that biological, psychological and sociocultural factors combine and interact to produce psychological disorders
Biofeedback
A system for electronically recording, amplifying, and feeding back information regarding a subtle physiological state, such as blood pressure or muscle tension
Biological psychology
A branch of psychology concerned with the links between biology and behavior. (Some biological psychologists call themselves behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists
Biological rhythms
Periodic physiological fluctuations
Bipolar disorder
A mood disorder in which the person alternates between the hopelessness and lethargy of depression and the overexcited state of mania
Blind spot
The point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there
Bottom-up processing
Analysis that begins with the sense receptors and works up to the brains integration of sensory information
Brainstem
The oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions
Broca's area
An area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech
Bulimia nervosa
An eating disorder characterized by private "binge-purge" episodes of overeating, usually of highly caloric foods, followed by vomiting or laxative use
Burnout
Physical, emotional, and mental exhaustion brought on by persistent job-related stress
Bystander effect
The tendency for any given bystander to be less likely to give aid if other bystanders are present
Cannon-Bard theory
The theory that an emotion-arousing stimulus simultaneously triggers (1) physiological responses and (2) the subjective experience of emotion
Case study
An observation technique in which one person is studied in depth in the hope of revealing universal principles
Catharsis
Emotional release. In psychology, the catharsis hypothesis maintains that "releasing" aggressive energy (through action or fantasy) relieves aggressive urges
Central nervous system (CNS)
the brain and spinal cord
Cerebellum
The "little brain" attached to the rear of the brainstem; it helps coordinate voluntary movement and balance
Cerebral cortex
The intricate fabric of interconnected neural cells that covers the cerebral hemispheres; the body's ultimate control and information-processing center
Chromosomes
Threadlike structures made of DNA molecules that contain the genes
Chunking
Organizing items into familiar, manageable units; often occurs automatically
Circadian rhythm
The biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24- hour cycle
Classical conditioning
A type of learning in which an organism comes to associate stimuli. A neutral stimulus that signals an unconditioned response (UCS) begins to produce a response that anticipates and prepares for the unconditioned stimulus (also called Pavlovian Conditioni
Client-centered therapy
A humanistic therapy, developed by Carl Rogers, in which the therapist uses techniques such as active listening within a genuine, accepting, empathic environment to facilitate clients' growth. (Also called person-centered therapy)
Clinical psychology
A branch of psychology that studies, assesses, and trests people with psychological disorders
Cochlea
A coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses
Cognition
All the mental activities associated with thinking, knowing, and remembering
Cognitive-behavior therapy
A popular integrated therapy that combines cognitive therapy (changing self-defeating thinking) with behavior therapy (changing behavior)
Cognitive dissonance theory
The theory that we act to reduce the discomfort (dissonance) we feel when two of our thoughts (cognitions) are inconsistent. For example, when our awareness of our attitudes and of our actions clash, we can reduce the resulting dissonance by changing our
Cognitive map
A mental representation of the layout of one's environment. For example, after exploring a maze, rats act as if they have learned a cognitive map of it
Cognitive therapy
Therapy that teaches people new, more adaptive ways of thinking and acting; based on the assumption that thoughts intervene between events and our emotional reactions
Collective unconscious
Carl Jung's concept of a shared, inherited reservoir of memory traces from our species' history
Collectivism
Giving priority to the goals of ones group and defining one's identity accordingly
Color constancy
Perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object
Companionate love
The deep affectionate attachment we feel for those whom are lives are intertwined
Complementary and alternative medicine
Unproven health care treatments not taught widely in medical school, not used in hospitals, and not usually reimbursed by insurance companies
Computer neural networks
Computer circuits that mimic the brain's interconnected neural cells, performing tasks such as learning to recognize visual patterns and smells
Concept
mental grouping of similar objects, events, ideas, or people
Concrete operational stage
In Piaget's theory, the stage of cognitive development from about 6 or 7 to 11 years of age during which children gain the mental operations that enable them to think logically about concrete events
Conditioned reinforcer
A stimulus that gains its reinforcing power though its association with a primary reinforcer
Conditioned response (CR)
In classical conditioning, the learned response to a previously neutral conditioned stimulus (CS)
Conditioned stimulus (CS)
In classical conditioning, an originally irrelevant stimulus that, after association with an unconditioned stimulus (UCS), comes to trigger a conditioned response
Conduction hearing loss
Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea
Cones
Receptor cells that are concentrates near the center of the retina and that function in daylight or in well-lit conditions. The cones detect finel detail and give rise to color sensations
Confirmation bias
A tendency to search for information that confirms one's preconceptions
Conflict
A perceived incompatibility of actions, goals, or ideas
Conformity
Adjusting one's behavior or thinking to coincide with a group standard
Consciousness
Our awareness of ourselves and our environments
Conservation
The principle (which Piaget believed to be a part of concrete operational reasoning) that properties such as mass, volume, and number remain the same despite changes in the forms of objects
Content validity
The extent to which a test samples the behavior that is interest (such as driving test samples driving tasks)
Continuous reinforcement
Reinforcing the desired response every time it occurs
Control condition
The condition of an experiment that contrasts with the experimental condition and serces as a comparison for evaluating the effect of the treatment
Convergence
A binocular cue for perceiving depth; the extent to which the eyes converge inward when looking at an object
Coronary heart disease
The clogging of the vessels that nourish the heart muscle; the leading cause of death in the United States
Corpus callosum
The large band of neural fibers connecting the two brain hemispheres and carrying messages between them
Correlation coefficient
A statistical measure of the extent to which two factors vary together, and thus, of how well either factor predicts the other
Counterconditioning
A behavior therapy procedure that conditions new responses to stimuli that trigger unwanted behaviors; based on classical conditioning
Creativity
The ability to produce novel and valuable ideas
Criterion
The behavior (such as college grades) that a test (such as the SAT) is designed to predict; thus, the measure used in defining whether the test has predictive validity
Critical period
An optimal period shortly after birth when an organism's exposure to certain stimuli or experiences produces proper development
Critical thinking
Thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions
Cross-sectional study
A study in which people of different ages are compared with one another
Crystallized intelligence
One's accumulated knowledge and verbal skills; tends to increase with age
CT (computer tomography scan)
A series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body
Culture
The enduring behaviors, ideas, attitude, and traditions shared by a large group of people and transmitted from one generation to the next
Defense mechanisms
In psychoanalytic theory, the ego's protective methods of reducing anxiety by unconsciously distorting reality
Deindividuation
The loss of self-awareness and self-restraint occurring in group situations that foster arousal and anonymity
D�j� vu
That eerie sense that "I've experienced this before". Cues form the current situation may subconsciously trigger retrieval of an earlier experience
Delta waves
The large, slow brain waves associated with deep sleep
Delusions
False beliefs, often of persecution or grandeur, that may accompany psychotic disorders
Dendrite
The bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body
Dependent variable
The experimental factor- in psychology, the behavior or mental process -that is being measured; the variable that may change in response to manipulations of the independent variable
Depressants
Drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow body functions
Depth perception
The ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance
Developmental psychology
A branch of psychology that studies physical, cognitive, and social change throughout the life span
Difference threshold
The minimum difference that a person can detect two stimuli. We experience the difference threshold as a just noticeable difference
Discrimination
In classical conditioning, the learned ability to distinguish between a conditioned stimulus and other stimuli that do not signal an unconditioned stimulus
Displacement
Defense mechanism that shifts sexual or aggressive impulses toward a more acceptable or less threatening object or person, as when redirecting anger toward a safer outlet
Dissociation
A split in consciousness, which allows some thoughts and behaviors to occur simultaneously with others
Dissociative disorders
Disorder in which conscious awareness becomes separated from previous memories, thoughts, or feelings
Dissociative identity disorder
A rare dissociative disorder in which a person exhibits two or more distinct and alternating personalities
DNA (deoxyribonucleic acid)
A complex molecule containing the genetic information that makes up the chromosomes A DNA molecule has two strands - forming a double helix - held together by bonds between pairs of nucleotides
Double-blind procedure
An experimental procedure in which both the research participants and the research staff are ignorant about whether the research participants have received the treatment or placebo. Commonly used in drug evaluation studies
Down syndrome
A condition of retardation and associated physical disorders caused by an extra chromosome in one's genetic makeup
Dream
A sequence of images, emotions, and thoughts passing through a sleeping person's mind. Dreams are notable for their hallucinatory imagery, discontinuities, and incongruities, and for the dreamer's delusional acceptance of the content and later difficultie
Drive-reduction theory
The idea that a physiological need creates an aroused tension state (a drive) that motivates an organism to satisfy the need
DSM-IV
The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, a widely used system for classifying psychological disorders
Dualism
The presumption that mind and body are two distinct entities that interact