Dictionary of Terms
Maintenance Rehearsal The rote repetition of information; repeating a given item over and over again.
Major Depression Persistent and severe feelings of sadness and worthlessness accompanied by changes in appetite, sleeping, and behavior.
Mania Excessive emotional arousal and wild, exuberant, unrealistic activity.
Manifest Content The apparent story line of a dream.
Masking Attempting to hide the expression of an emotion.
Matching A systematic selection of subjects in groups in an experiment or (more often) a correlational study to ensure that the mean values of important subject variables of the groups are similar.
Materialism A philosophical belief that reality can be known only through an understanding of the physical world of which the mind is a part.
Maturation Any relatively stable change in thought, behavior, or physical growth that is due to the aging process and not to experience.
Mean A measure of central tendency; the sum of a group of values divided by their number; the arithmetical average.
Means-Ends Analysis A general heuristic method of problem solving that involves looking for differences between the current state and the goal state and seeking ways to reduce the differences.
Measure of Central Tendency A statistical measure used to characterize the value of items in a sample of numbers.
Measure of Variability A statistical measure used to characterize the dispersion in values of items in a sample of numbers.
Median A measure of central tendency; the midpoint of a group of values arranged numerically.
Medulla The part of the brain stem closest to the spinal cord; controls vital functions such as heart rate and blood pressure.
Meiosis The form of cell division by which new sperm and ova are formed. The chromosomes within the cell are randomly rearranged so that new sperm and ova contain 23 individual chromosomes, or half of that found in other cells of the body.
Memory The cognitive processes of encoding, storing, and retrieving information.
Meninges The three-layered set of membranes that enclose the brain and spinal cord.
Mental Age A measure of a personís intellectual development; the level of intellectual development that could be expected for an average child of a particular age.
Mental Model A mental construction based on physical reality that is used to solve problems of logical deduction.
Mental Retardation Mental development that is substantially below normal; often caused by some form of brain damage or abnormal brain development.
Mental Space (M-Space) A hypothetical construct in Caseís model of cognitive development similar to working memory, whose primary function is to process information from the external world.
Mere Exposure Effect The formation of a positive attitude toward a person, place, or thing based solely on repeated exposure to that person, place, or thing.
Meta-Analysis A statistical procedure by which the results of many studies are combined to estimate the magnitude of a particular effect.
Method of Loci A mnemonic system in which items to be remembered are mentally associated with specific physical locations or landmarks.
Midbrain The part of the brain stem just anterior to the pons; involved in control of fighting and sexual behavior and in decreased sensitivity to pain during these behaviors.
Minnesota Multiphasic Personality Inventory (MMPI) An objective test originally designed to distinguish individuals with different psychological problems from normal individuals. It has since become popular as a means of attempting to identify personality characteristics of people in many everyday settings.
Mnemonic System A special technique or strategy consciously employed in an attempt to improve memory.
Model A relatively simple system that works on known principles and is able to do at least some of the things that a more complex system can do.
Modulation An attempt to exaggerate or minimize the expression of an emotion.
Monogamy The mating of one female and one male.
Mood Disorder A disorder characterized by significant shifts or disturbances in mood that affect normal perception, thought, and behavior. Mood disorders may be characterized by deep, foreboding depression, or a combination of the depression and euphoria.
Moral Realism The first stage of Piagetís model of moral development, which includes egocentrism and blind adherence to rules.
Morality of Cooperation The second stage of Piagetís model of moral development, which involves the recognition of rules as social conventions.
Motion Parallax A cue of depth perception. As we pass by a scene, objects closer to us pass in front of objects farther away.
Motivation A general term for a group of phenomena that affect the nature, strength, or persistence of an individualís behavior.
Motor Association Cortex Those regions of cerebral cortex that control the primary motor cortex; involved in planning and executing behaviors.
Motor Neuron A neuron whose terminal buttons form synapses with muscle fibers. When an action potential travels down its axon, the associated muscle fibers will twitch.
Multiple Personality Disorder A rarely seen dissociative disorder in which two or more distinct personalities exist within the same person; each personality dominates in turn.
Muscle Spindle A muscle fiber that functions as a stretch receptor, arranged parallel to the muscle fibers responsible for contraction of the muscle, thus detecting muscle length.
Mutations Accidental alterations in the DNA code within a single gene. Mutations can either be spontaneous and occur naturally or be the result of environmental factors such as exposure to high-energy radiation.
Myelin Sheath The insulating material that encases most large axons.