AP PSYCHOLOGY UNIT 2

neuron

neuron

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

dendrites

a neuron’s bushy, branching extensions that receive message and conduct impulse toward the cell body

axon

the neuron extension that passes a message through its branches to other neurons or to other muscles or glands

myelin sheath

a fatty tissue layer segmentally encasing the axons of some neurons or to muscles or glands

action potential

a neural impulse; a brief electric charge that travels down an axon

resting potential

positive-outside/negative-inside state

refractory period

refractory period

threshold

the level of stimulation required to trigger a neural impulse

all-or-nothing 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

synaptic gap (synaptic cleft)

the tiny gap at the synapse

neurotransmitter

chemical messengers that cross the synaptic gaps between neurons; when released by the sending neuron, they travel across he 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

aceylcholine (ACh)

a neurotransmitter that enables muscle action, learning, and memory; undersupply linked to Alzheimer’s disease

dopamine

a neurotransmitter that influences movement, learning, attention, and emotion; oversupply linked to schizophrenia, undersupply linked to Parkinson’s disease

serotonin

a neurotransmitter that affects mood, hunger, sleep, and arousal; undersupply linked to depression

norepinephrine

a neurotransmitter that helps control alertness and arousal; controls body’s fight-or-flight response; undersupply can depress mood

GABA (gamma-aminobutyric acid)

a major inhibitory neurotransmitter; undersupply linked to seizures, tremors, and insomnia

glutamate

a major excitatory neurotransmitter; involved in memory; oversupply linked to migraines and seizures

endorphins

“morphine within” - natural, opiate-like neurotransmitters linked to pain control and pleasure

agonist

a molecule that, by binding to a receptor site, simulates a response

antagonist

a molecule that, by binding to a receptor site, inhibits or blocks a response

nervous system

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

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

sensory (afferent) neurons

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

motor (efferent) neurons

neurons that carry outgoing info 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

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)

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 (ANS) that calms the body, conserving its energy

reflex

a simple, automatic response to a sensory stimulus

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 kidney and secret hormones (epinephrine and norepinephrine) that helps arouse the body in times of stress; controls “flight or flight” response

pituitary gland

the endocrine system’s most influential gland under the influence of the hypothalamus, the pituitary gland regulates growth and controls other endocrine glands

electroencephalogram (EEG)

an amplified recording of the waves of electrical activity sweeping across the brain’s surface

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) 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

fMRI (functional MRI)

a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans

brainstem

the oldest part and 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 base of the brainstem; controls heartbeat and breathing (keeps us alive)

pons

helps coordinate movements

thalamus

the brain’s sensory control center, located on top of the brainstem; directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla; receives information from all the senses except smell and routes it to higher brain regions

reticular formation

a nerve network that travels though the brainstem and thalamus and plays an important role in controlling arousal; when damaged a coma is possible

cerebellum

the “little brain” at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory (autonomic memory)

limbic system

neural system located below the cerebral hemispheres; associated with emotions and drives; includes the amygdala, hypothalamus, and hippocampus

amygdala

two lima-bean-sized neural clusters in the limbic system; linked to emotion (arousal), specifically aggression and fear

hypothalamus

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

hippocampus

in the limbic system; processes conscious memories (like a “save button”); helps process explicit memories for storage

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; they may also play a role in learning and thinking

frontal lobes

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

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

somatosensory 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 aren't involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking

prefrontal cortex

in the forward part of the frontal lobes enables judgement, planning, and processing of new memories

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; sleep, exercise, and brain breaks facilitate it

lateralization

our brain’s look-alike left and right hemispheres serve differing functions

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 brains two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them

left hemisphere

adept at making quick, literal interpretations of language (logic)

right hemisphere

excels in making inferences; helps modulate speech (to make meaning more clear); helps orchestrate sense of self (creativity)

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 psychological defense mechanism, caused by self-protective need to deny visual information that might cause fear, anxiety, or shame

behavior genetics

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

environment

every external influence, from prenatal nutrition to the people and things around us

identical twins (monozygotic twins)

twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms; may not always have the same number of copies of those genes

fraternal twins (dizygotic 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; may, depending on the range of population and environments studied; “variation within a group” - can’t be applied to individuals

evolutionary psychology

the study of the evolution of behavior that the mind, using principles of natural selection

natural selection

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

circadian rhythm

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

REM sleep (rapid eye movement sleep or paradoxical sleep)

a recurring sleep stage during which vivid dreams commonly occur; 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 distant from unconsciousness resulting from a coma, general anesthesia, or hibernation

NREM-1 (non-REM stage 1)

may experience hallucinations or hypnagogic sensations

hallucinations

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

hypnagognic sensations

sensation of falling (at which moment your body may suddenly jerk) or of floating weightlessly due to hallucinations

NREM-2 (non-REM stage 2)

periodic sleep spindles; could still be awakened without too much difficulty; clearly asleep

sleep spindles

bursts of rapid, rhythmic brain-wave activity

NREM-3 (non-REM stage 3 or delta sleep)

slow wave sleep; the brain emits large slow delta waves and you are hard to awaken

NREM sleep (non-rapid eye movement sleep)

encompasses all sleep stages except for REM 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 an inopportune time

sleep apnea

a sleep disorder characterized by temporary cessations (process of ending) of breathing during sleep and repeated momentary awakenings; tends to happen during NREM-3 sleep

night terrors

a sleep disorder characterized by temporary cessations of breathing during sleep and repeat momentary awakenings; tends to happen during NREM-3 sleep

dream

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

REM rebound

the tendency from REM sleep to increase following REM sleep deprivation (created by repeated awakenings during REM sleep)

depressants

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

stimulants

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

hallucinogens

psychedelic (“mind-manifesting”) drugs (such as LSD, marijuana, and TCH) that distort perceptions and evoke sensory images in the absence of sensory input