a branch of psychology concerned with the links between biology and behavior.
a nerve cell; the basic building block of the nervous system.
neuron extensions that receive messages and conduct impulses toward the cell body.
neuron extensions that pass messages to other neurons or cells.
a nerve impulse.
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.
the level of stimulation required to trigger a neural impulse.
a neuron's reaction of either firing (with a full-strength response) or not firing.
neuron-produced chemicals that cross synapses to carry messages to other neurons or cells.
chemicals, such as opium, morphine, and heroin, that depress neural activity, temporarily lessening pain and anxiety.
"morphine within"-natural, opiatelike neurotransmitters linked to pain control to pleasure.
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 connecting the central nervous system (CNS) to the rest of the body.
bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs.
neurons that carry incoming information from the sensory receptors to the central nervous system.
neurons that carry outgoing information from the central nervous to the muscles and glands.
neurons that communicate internally and intervene between the sensory inputs and motor outputs.
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 division 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.
the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream.
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.
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.
the endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.
the oldest part and central core of the brain, beginning where the spinal cords swells as it enters the skull; the brainstem is responsible for automatic survival functions.
the base of the brainstem; controls heartbeat and breathing.
recording apparatus, using electrodes placed on the scalp, that records waves of electrical activity that sweep across the brain's surface.
PET (positron emission tomography) scan
a view of brain activity showing 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. show brain anatomy.
fMRI (functional magnetic resonance imaging)
a technique for revealing bloodflow and therefore, brain activity by comparing successive MRI scans. show brain function.
area at the top of the brainstem; directs sensory messages to the cortex and transmits replies to the cerebellum and medulla.
a nerve network in the brainstem that plays an important role in controlling arousal.
the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance.
neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.
two lima-bean-sized neural clusters in the limbic system; linked to emotion.
a neural structure lying below the thalamus; directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion.
thin layer of interconnected neurons covering the cerebral hemispheres; the body's ultimate control and information-processing center.
portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments.
portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position.
portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields.
portion of the cerebral cortex lying roughly above the ears; includes ares that receive information from the ears.
area at the rear of the frontal lobe; controls voluntary movements.
area at the front of the parietal lobes that registers and processes body touch and movement sensations.
false sensory experiences, such as hearing something in the absence of an external auditory stimulus.
areas of the cerebral cortex that are primarily involved in higher mental functions such as learning, remembering, thinking, and speaking.
an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech; controls language expression.
a brain area, usually in the left temporal lobe, involved in the left temporal lobe, involved in language comprehension and expression; controls language reception.
the brain's ability to change, especially during childhood by reorganizing after damage or by building new pathways based on experience.
large band of neural fibers connecting the two brain hemispheres and carrying messages between them.
condition in which the brain's two hemispheres are isolated by cutting the fibers (mainly those of the corpus callosum) connecting them.
subfield of psychology that studies the connections between our brain activity and the processes of thinking, knowing, remembering, and communicating.
our awareness of ourselves and our environment.
focusing conscious awareness on a particular stimulus.
failure to see visible objects when our attention is directed elsewhere.
the biological clock; regular-bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle.
REM (rapid eye movement) sleep
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.
relatively slow brain waves of a relaxed, awake state.
periodic, natural, reversible loss of consciousness-as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation.
recurring problems in falling or staying asleep.
sleep disorder in which a person has uncontrollable sleep attacks, sometimes lapsing directly into REM sleep.
a sleep disorder in which a sleeping person repeatedly stops breathing until blood oxygen is so low it awakens the person just long enough to draw a breath.
a sequence of images, emotions, and thoughts passing through a sleeping person's mind.
according to Freud, the remembered story line of a dream.
according to Freud, the underlying meaning of a dream.
the tendency for REM sleep to increases following REM sleep deprivation (created by repeated awakenings during REM sleep).