major depressive disorder A condition characterized by one or more episodes of deep sadness and despair, each of which persists virtually all day for a period of at least two weeks. 15
malleus One of a set of three tiny, interconnected bones in the middle ear that transmit sound from the eardrum to the cochlea. 4
mania A condition that is characterized by one or more periods of exaggerated elation. When depression is combined with mania, the resulting syndrome is known as bipolar disorder. 15
manifest content In psychoanalysis, the plot or story line of a dream. 5, 16
mean The arithmetic average of a set of numbers. 2
means-end analysis A heuristic that involves comparing one’s current position to the desired state (the “end”) and then trying to find a way to attain the end (the “means”). 8
median The number that falls in the exact middle of a distribution of numbers arranged from highest to lowest. 2
meditation The focusing of attention on a single stimulus, thus restricting sensory input and producing an altered state of consciousness. 5
medulla The part of the hindbrain that controls autonomic activities, such as circulation and breathing, and is also involved in chewing, salivation, and facial movements. 3
memory skill hypothesis Ericsson’s theory that memory is characterized by three properties: meaningful and redundant encoding, rich and highly associated retrieval cues stored with items, and increased performance through tremendous practice. 7
menarche The start of the menstrual cycle. 10
mental set The inclination to apply an old or inappropriate perspective to a new situation. 8
mentally gifted A person whose general intelligence has from childhood been significantly above average. 14
mentally retarded A person whose general intelligence has from childhood been significantly below average, and who consistently has difficulty functioning in everyday settings. 14
metabolic rate The rate at which food energy is burned away. 12
metacognition The ability to monitor one’s own thoughts. 9
method of loci A mnemonic device for organizing material when storing it in long-term memory. It involves associating the items to be remembered with a series of places, or loci, already firmly fixed in memory. 7
midbrain A small area in the brain’s central core above the hindbrain containing centers for visual and auditory reflexes. 3
Minnesota Multiphasic Personality Inventory (MMPI) A self-report personality test designed to provide a detailed list of a subject’s personality traits based on his or her answers to a series of over 550 statements. 14
misinformation acceptance The unconscious adoption of untruths into one’s memory after the fact. 7
mode The number or score that is most frequently obtained in a distribution. 2
modeling The process by which someone learns a new behavior by observing other people perform that behavior. 16
monoamines Neurotransmitters such as dopamine, norepinephrine, and serotonin that play critical roles in emotion, movement, learning, and memory. 3
monochromats People whose cones contain only one form of iodopsin and who thus see shades of gray. 4
monocular depth cues Perceptual cues that augment depth perception and are potentially available to one eye only. 4
mood disorders People with mood disorders can feel intensely marvelous or miserable for long periods of time and for no apparent reason. As a result, their emotions come to distort their entire outlook and interfere greatly with their normal lives. 15
mood-congruent recall A bias in retrieving memories where a positive mood may act to screen out negative thoughts and situations, and vice versa. 7
mood-dependent memory Memory that is easier to retrieve when the person is in the psychological state in which the information was originally stored. 7
Moro reflex A startle response that occurs in reaction to an intense, sudden movement or noise. 9
morphemes The combining of phonemes into meaningful units of speech that cannot be subdivided without losing their meaning. 8
motion parallax A monocular depth cue; the differences in the relative movement of retinal images that occur when we change position. 4
motivation That which gives impetus to behavior by arousing, sustaining, and directing it toward the attainment of goals. 11
multiple memory systems Endel Tulving’s theory that memory is composed of a hierarchy of systems consisting of procedural memories (the most basic), semantic memory (relying on verbal abilities), and episodic memory (relating to specific episodes in the past). 7
myelin sheath The fatty, whitish substance around an axon. 3