AP Psych. Unit 1.

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 chord

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 sensory 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

the

division of the peripheral

nervous system that controls the

body's skeletal muscles. Also

called the skeletal nervous system.

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.

sympathetic nervous

system

the division of the

autonomic nervous system that

arouses the body, mobilizing its

energy.

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 reflex.

neuron

a nerve cell; the basic

building block of the nervous

system.

cell body

the part of a neuron

that contains the nucleus; the

cell's life-support center.

dendrites

a neuron's often

bushy, branching extensions that

receive and integrate messages,

conducting impulses toward the

cell body.

axon

the segmented neuron

extension that passes messages

through its branches to other

neurons or to muscles or glands.

myelin sheath

a

fatty tissue layer segmentally

encasing the axons of some

neurons; it enables vastly greater

transmission speed as neural

impulses hop from one node to

the next.

glial cells (glia)

cells in the

nervous system that support,

nourish, and protect neurons;

they may also play a role in

learning, thinking, and memory.

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.

refractory period

in neural

processing, a brief resting pause

that occurs after a neuron

has fired; subsequent action

potentials cannot occur until the

axon returns to its resting state.

all-or-none response

a

neuron's reaction of either firing

(with a full-strength response) or

not firing.

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

gap between neurons. When

released by the sending neuron,

neurotransmitters 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,

opioid-like neurotransmitters

linked to pain control and to

pleasure.

agonist

a molecule that

increases a neurotransmitter's

action.

antagonist

a molecule

that inhibits or blocks a

neurotransmitter's action.

hormones

chemical messengers

that are manufactured by the

endocrine glands, travel through

the bloodstream, and affect other

tissues.

Consciousness

our subjective

awareness of ourselves and our

environment.

cognitive neuroscience

the interdisciplinary study

of the brain activity linked

with cognition (thinking,

knowing, remembering, and

communicating).

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

multiple aspects of a stimulus or

problem simultaneously.

sequential processing

processing one aspect of a

stimulus or problem at a time;

generally used to process new

information or to solve difficult

problems.

sleep

a periodic, natural loss

of consciousness-?as distinct

from unconsciousness resulting

from a coma, general anesthesia,

or hibernation. (Adapted from

Dement, 1999)

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.

(Sometimes called R sleep.)

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 to sleep. (Also

called hypnic sensations.)

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, the SCN adjusts 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 affected person

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 normal

REM paralysis does not occur;

instead, twitching, talking, or

even kicking or punching may

occur, often acting out one's

dream.

dream

a sequence of images,

emotions, and thoughts passing

through a sleeping person's

mind.

REM rebound

the tendency for

REM sleep to increase following

REM sleep deprivation.

hindbrain

consists of the

medulla, pons, and cerebellum;

directs essential survival

functions, such as breathing,

sleeping, and wakefulness, as

well as coordination and balance.

midbrain

found atop the

brainstem; connects the hindbrain

with the forebrain, controls some

motor movement, and transmits

auditory and visual information.

forebrain

consists of the

cerebral cortex, thalamus, and

hypothalamus; manages complex

cognitive activities, sensory

and associative functions, and

voluntary motor activities.

brainstem

the central core

of the brain, beginning where

the spinal cord swells as it

enters the skull; the brainstem

is responsible for automatic

survival functions.

medulla

the

hindbrain structure that is

the brainstem's base; controls

heartbeat and breathing.

thalamus

the forebrain's sensory control

center, 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.

reticular formation

a nerve

network that travels through the

brainstem into the thalamus;

it filters information and plays

an important role in controlling

arousal.

cerebellum

the hindbrain's

"little brain" at the rear of the

brainstem; its functions include

processing sensory input,

coordinating movement output

and balance, and enabling

nonverbal learning and memory.

limbic system

neural.

system located mostly in the

forebrain ?below the cerebral:

hemispheres ? that includes

the amygdala, hypothalamus,

hippocampus, thalamus, and

pituitary gland; associated with

emotions and drives.

amygdala

two lima-bean-sized neural

clusters in the limbic system;

linked to emotion.

hypothalamus

a limbic system neural

structure lying below (hypo)

the thalamus; it directs several

maintenance activities (eating,

drinking, body temperature), helps

gover the endocrine system, and

is linked to emotion and reward.

hippocampus

neural center

in the limbic system that helps

process explicit (conscious)

memories ? of facts and

events? for storage.

cerebral cortex

the intricate fabric of

interconnected neural cells

covering the forebrain's cerebral

hemispheres; the body's ultimate

control and information-

processing center.

frontal lobes

the portion of

the cerebral cortex lying just

behind the forehead. They

enable linguistic processing,

muscle movements, higher-

order thinking, and executive

functioning (such as making

plans and judgments).

parietal lobes

the portion of the

cerebral cortex lying at the top of

the head and toward the rear; it

receives sensory input for touch

and body position.

occipital lobes

the portion of the

cerebral cortex lying at the back

of the head; it includes areas that

receive information from the

visual fields.

temporal lobes

the portion of

the cerebral cortex lying roughly

above the ears; it includes the

auditory areas, each of which

receives information primarily

from the opposite ear. They also

enable language processing.

motor cortex

a cerebral cortex

area at the rear of the frontal

lobes that controls voluntary

movements.

somatosensory cortex

a cerebral 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, but rather

are involved in higher mental

functions such as learning,

remembering, thinking, and

speaking.

neurogenesis

the formation of

new neurons.

corpus callosum

he large band

of neural fibers connecting the

two brain hemispheres and

carrying messages between

them.

psychoactive drug

chemical

substance that alters the brain,

causing changes in perceptions

and moods.

substance use disorder

a disorder characterized by

continued substance use despite

resulting life disruption.

depressants

drugs that reduce

neural activity and slow body

functions.

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

drugs effect.

addiction

an everyday term for

compulsive substance use (and

sometimes for dysfunctional

behavior patterns, such as

out-of-control gambling)

that continue despite harmful

consequences. (See also

substance use disorder.)

withdrawal

he discomfort and

distress that follow discontinuing

an addictive drug or behavior.

barbiturates

drugs that depress

central nervous system activity,

reducing anxiety but impairing

memory and judgment.

opioids

opium and its

derivatives; they depress neural

activity, temporarily lessening

pain and anxiety.

stimulants

drugs that excite

neural activity and speed up

body functions.

hallucinogens

psychedelic

("mind-manifesting") drugs 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 cardiac arrest);

often similar to drug-induced

hallucinations.

biopsychosocial approach

an integrated approach that

incorporates biological, psycho-

logical, and social-cultural levels

of analysis.

levels of analysis

the differing

complementary views, from

biological to psychological to

social-cultural, for analyzing any

given phenomenon.

neuroplasticity

the brain's

ability to change, especially

during childhood, by reorganizing

after damage or by building new

pathways based on experience.

lesion

tissue

destruction. Brain lesions may

occur naturally (from disease

or trauma), during surgery, or

experimentally (using electrodes

to destroy brain cells).

EEG (electroencephalogram)

an amplified recording of the

waves of electrical activity

sweeping across the brain's

surface. These waves are

measured by electrodes placed

on the scalp.

MEG (magnetoencephalography)

a brain-imaging technique that

measures magnetic fields from the

brain's natural electrical activity.

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 of the

brain's structure.

PET (positron emission

tomography)

a technique for

detecting brain activity that

displays where a radioactive

form of glucose goes while the

brain performs a given task.

MRI (magnetic resonance

imaging)

technique that uses

magnetic fields and radio waves

to produce computer-generated

images of soft tissue. MRI scans

show brain anatomy.

MRI (functional MRI)

a technique for revealing blood

flow and, therefore, brain activity

by comparing successive MRI

scans. fMRI scans show brain

function as well as structure.