AP Psych Vocab 2

biological psychology

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

neuron

a nerve cell; the basic building block of the nervous system.

sensory neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord.

motor 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 that communicate internally and intervene between the sensory inputs and motor outputs.

dendrites

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body.

axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands.

myelin sheath

a layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

action potential

a neural impulse; a brief electrical charge that travels down an axon.

threshold

the level of stimulation required to trigger a neural impulse.

synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft.

neurotransmitters

chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, they travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.

reuptake

a neurotransmitter's reabsorption by the sending neuron.

endorphins

"morphine within"—natural, opiate-like neurotransmitters linked to pain control and to pleasure.

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.

somatic nervous system

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

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.

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy.

reflex

a simple, automatic response to a sensory stimulus, such as the knee-jerk response.

endocrine system

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream.

hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.

adrenal glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.

pituitary gland

the endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

lesion

tissue destruction. A naturally or experimentally caused destruction of brain tissue.

electroencephalogram (EEG)

an amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp.

CT (computed 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. Also called CAT scan.

PET (positron emission tomography) scan

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task.

MRI (magnetic resonance imaging)

a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. They scans show brain anatomy.

fMRI (functional MRI)

a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. These scans show brain function.

brainstem

the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; It is responsible for automatic survival functions.

medulla

the base of the brainstem; controls heartbeat and breathing.

reticular formation

a nerve network in the brainstem that plays an important role in controlling arousal.

thalamus

the brain's sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.

cerebellum

the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance.

limbic system

doughnut-shaped neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.

amygdala

two lima bean-sized neural clusters in the limbic system; linked to emotion.

hypothalamus

a neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

cerebral cortex

the intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center.

glial cells (glia)

cells in the nervous system that support, nourish, and protect neurons.

frontal lobes

portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments.

parietal lobes

portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position.

occipital lobes

portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields.

temporal lobes

portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear.

motor cortex

an area at the rear of the frontal lobes that controls voluntary movements.

sensory cortex

area at the front of the parietal lobes that registers and processes body touch and movement sensations.

association areas

areas of the 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.

aphasia

impairment of language, usually caused by left hemisphere damage either to Broca's area (impairing speaking) or to Wernicke's area (impairing understanding).

Broca's area

controls language expression—an area, usually in the left frontal lobe, that directs the muscle movements involved in speech.

Wernicke's area

controls language reception—a brain area involved in language comprehension and expression; usually in the left temporal lobe.

plasticity

the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.

neurogenesis

the formation of new neurons.

corpus callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them.

split brain

a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.

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.

behavior genetics

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

environment

every non-genetic influence, from prenatal nutrition to the people and things around us.

chromosomes

threadlike structures made of DNA molecules that contain the genes.

DNA (deoxyribonucleic acid)

a complex molecule containing the genetic information that makes up the chromosomes.

genes

the biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing a protein.

genome

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

identical twins

twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms.

fraternal twins

twins who develop from separate fertilized eggs. They are genetically no closer than brothers and sisters, but they share a fetal environment.

heritability

the proportion of variation among individuals that we can attribute to genes. This may vary, depending on the range of populations and environments studied.

interaction

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

molecular genetics

the sub-field of biology that studies the molecular structure and function of genes.

evolutionary psychology

the study of the roots of behavior and mental processes using the principles of natural selection.

natural selection

the principle that, among the range of inherited trait variations, those contributing to reproduction and survival will most likely be passed on to succeeding generations.

mutation

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

consciousness

our awareness of ourselves and our environment.

circadian rhythm

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

REM (rapid eye movement) 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.

sleep

periodic, natural loss of consciousness—as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation. (Adapted from Dement, 1999.)

hallucinations

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

delta waves

the large, slow brain waves associated with deep sleep.

NREM sleep

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

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.

night terrors

a sleep disorder characterized by high arousal and an appearance of being terrified; unlike nightmares, these occur during Stage 4 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. These are notable for their hallucinatory imagery, discontinuities, and incongruities, and for the person 's delusional acceptance of the content and later difficulties remembering it.

manifest content

according to Freud, the story of the dream.

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 (created by repeated awakenings during REM sleep).

hypnosis

a social interaction in which one person suggests to another that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur.

posthypnotic suggestion

a suggestion, made during a hypnosis session, to be carried out after the subject is no longer hypnotized; used by some clinicians to help control undesired symptoms and behaviors.

dissociation

a split in consciousness, which allows some thoughts and behaviors to occur simultaneously with others.

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.

withdrawal

the discomfort and distress that follow discontinuing the use of an addictive drug.

physical dependence

a physiological need for a drug, marked by unpleasant withdrawal symptoms when the drug is discontinued.

psychological dependence

a psychological need to use a drug, such as to relieve negative emotions.

addiction

compulsive drug craving and use, despite adverse consequences.

depressants

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

barbiturates

drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgment.