Unit 1 (W/O Researchers)

psychology

The science of behavior and mental processes.

nature–nurture issue

The longstanding controversy over the relative contributions that genes and experience make to the development of psychological traits and behaviors. Today’s science views traits and behaviors as arising from the interaction of nature and nurture.

natural selection

The principle that the inherited traits enabling an organism to survive and reproduce in a particular environment will (in competition with other trait variations) most likely be passed on to succeeding generations.

evolutionary psychology

The study of the evolution of behavior and the mind, using principles of natural selection.

behavior genetics

The study of the relative power and limits of genetic and environmental influences on behavior.

biological psychology

A branch of psychology concerned with the links between biology and behavior.

biopsychosocial approach

An integrated approach that incorporates biological, psychological, and social-cultural viewpoints.

levels of analysis

The differing complementary views, from biological to psychological to social-cultural, for analyzing any given phenomenon.

mutation

A random error in gene replication that leads to a change.

environment

Every nongenetic influence, from prenatal nutrition to our experiences of the people and things around us.

heredity

The genetic transfer of characteristics from parents to offspring.

genes

The biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins.

genome

The complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes.

identical (monozygotic) twins

Individuals who developed from a single fertilized egg that split in two, creating two genetically identical organisms.

fraternal (dizygotic) twins

Individuals who developed from separate fertilized eggs. They are genetically no closer than ordinary siblings, but they shared a prenatal environment.

interaction

The interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity).

epigenetics

The study of the molecular mechanisms by which environments can influence genetic expression (without a DNA change).

consciousness

our subjective awareness of ourselves and our environment.

cognitive neuroscience

the interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language).

dual processing

the principle that information is often simultaneously processed on separate conscious and unconscious tracks.

blindsight

a condition in which a person can respond to a visual stimulus without consciously experiencing it.

parallel processing

processing many aspects of a problem or stimulus simultaneously; the brain’s natural mode of information processing for many functions.

sequential processing

processing one aspect of a problem or stimulus at a time; generally used to process new information or to solve difficult problems.

sleep

periodic, natural loss of consciousness — as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation.

circadian rhythm

our biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle.

REM sleep

rapid eye movement sleep; a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active.

alpha waves

the relatively slow brain waves of a relaxed, awake state.

NREM sleep

non-rapid eye movement sleep; encompasses all sleep stages except for REM sleep.

hallucinations

false sensory experiences, such as seeing something in the absence of an external visual stimulus.

hypnagogic sensations

bizarre experiences, such as jerking or a feeling of falling or floating weightlessly, while transitioning into sleep.

delta waves

the large, slow brain waves associated with deep sleep.

suprachiasmatic nucleus (SCN)

a pair of cell clusters in the hypothalamus that controls circadian rhythm. In response to light, it causes the pineal gland to adjust melatonin production, thus modifying our feelings of sleepiness.

insomnia

recurring problems in falling or staying asleep.

narcolepsy

a sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times.

sleep apnea

a sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings.

REM sleep behavior disorder

a sleep disorder in which the normal paralysis associated with REM sleep does not occur, leading individuals to physically act out their dreams.

night terrors

a sleep disorder characterized by high arousal and an appearance of being terrified; unlike nightmares, these occur during NREM-3 sleep, within two or three hours of falling asleep, and are seldom remembered.

dream

a sequence of images, emotions, and thoughts passing through a sleeping person’s mind.

manifest content

according to Freud, the symbolic, remembered story line of a dream (as distinct from its latent, or hidden, content).

latent content

according to Freud, the underlying meaning of a dream (as distinct from its manifest content).

REM rebound

the tendency for REM sleep to increase following REM sleep deprivation.

sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

perception

the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

sensory receptors

sensory nerve endings that respond to stimuli.

bottom-up processing

analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information.

top-down processing

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.

transduction

conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret.

psychophysics

the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.

absolute threshold

the minimum stimulus energy needed to detect a particular stimulus 50 percent of the time.

signal detection theory

a theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person’s experience, expectations, motivation, and alertness.

subliminal

below one’s absolute threshold for conscious awareness.

priming

the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response.

difference threshold

the minimum difference between two stimuli required for detection 50 percent of the time. We experience the _______ as a just noticeable difference (or jnd).

Weber’s law

the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount).

sensory adaptation

diminished sensitivity as a consequence of constant stimulation.

wavelength

the distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of gamma rays to the long pulses of radio transmission.

hue

the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth.

intensity

the amount of energy in a light or sound wave, which influences what we perceive as brightness or loudness. Determined by the wave’s amplitude (height).

cornea

the transparent tissue that covers the front of the eye and bends light to provide focus.

pupil

the adjustable opening in the center of the eye through which light enters.

iris

a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening.

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina.

retina

the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.

accommodation

in sensation and perception, the process by which the eye’s lens changes shape to focus near or far objects on the retina.

rods

retinal receptors that detect black, white, and gray, and are sensitive to movement; necessary for peripheral and twilight vision, when cones don’t respond.

cones

retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. They detect fine detail and give rise to color sensations.

optic nerve

the nerve that carries neural impulses from the eye to the brain.

blind spot

the point at which the optic nerve leaves the eye, creating a ______ because no receptor cells are located there.

fovea

the central focal point in the retina, around which the eye’s cones cluster.

Young-Helmholtz trichromatic (three-color) theory

the theory that the retina contains three different types of color receptors — one most sensitive to red, one to green, one to blue — which, when stimulated in combination, can produce the perception of any color.

opponent-process theory

the theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.

feature detectors

nerve cells in the brain’s visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement.

substance use disorder

A disorder characterized by continued substance craving and use despite significant life disruption and/or physical risk.

psychoactive drug

A chemical substance that alters perceptions and moods.

tolerance

The diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug’s effect.

addiction

A primary, chronic disease of brain reward, motivation, memory, and related circuitry; characterized by an inability to consistently abstain, impairment in behavioral control, craving, diminished recognition of significant problems, and a dysfunctional emotional response.

withdrawal

The discomfort and distress that follow discontinuing an addictive drug or behavior.

depressants

Drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow body functions.

alcohol use disorder

(Popularly known as alcoholism) alcohol use marked by tolerance, withdrawal, and a drive to continue problematic use.

barbiturates

Drugs that depress central nervous system activity, reducing anxiety but impairing memory and judgment.

opiates / opioids

Opium and its derivatives, such as morphine and heroin; depress neural activity, temporarily lessening pain and anxiety.

stimulants

Drugs (such as caffeine, nicotine, and the more powerful amphetamines, cocaine, Ecstasy, and methamphetamine) that excite neural activity and speed up body functions.

nicotine

A stimulating and highly addictive psychoactive drug in tobacco.

cocaine

A powerful and addictive stimulant derived from the coca plant; produces temporarily increased alertness and euphoria.

amphetamines

Drugs that stimulate neural activity, causing accelerated body functions and associated energy and mood change (Meth as an example).

methamphetamine

A powerfully addictive drug that stimulates the central nervous system, with accelerated body functions and associated energy and mood changes; over time, appears to reduce baseline dopamine levels.

Ecstasy (MDMA)

A synthetic stimulant and mild hallucinogen. Produces euphoria and social intimacy, but with short-term health risks and longer-term harm to serotonin-producing neurons and to mood and cognition.

hallucinogens

Psychedelic ("mind-manifesting") drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input.

near-death experience

An altered state of consciousness reported after a close brush with death (such as through cardiac arrest); often similar to drug-induced hallucinations.

LSD

A powerful hallucinogenic drug; also known as acid (lysergic acid diethylamide).

THC

The major active ingredient in marijuana; triggers a variety of effects, including mild hallucinations.

nervous system

The body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.

central nervous system (CNS)

The brain and spinal cord.

peripheral nervous system (PNS)

The sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

nerves

Bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs.

sensory (afferent) neurons

Neurons that carry incoming information from the body's tissues and sensory receptors to the brain and spinal cord.

motor (efferent) neurons

Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.

interneurons

Neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs.

somatic nervous system / skeletal nervous system

The division of the peripheral nervous system that controls the body's skeletal muscles.

autonomic nervous system (ANS)

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.