AP Psych unit 3

Plasticity

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

Neurons

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

Bushy fibers that receive and integrate messages, conducting impulses toward the cell body. Short. “Listen”

Axon

The neuron extension that passes messages through its branches to other neurons or to muscles or glands. Can be very long. “Speak”

Myelin Sheath

A fatty tissue lager segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next. If myelin sheath degenerates, multiple sclerosis occurs.

Glial cells

Cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory.

Action potential

A neural impulse; a brief electrical charge that travels down an axon. Speeds from 2 mph to 200 mph.

Resting potential

This positive-outside, negative-inside state

Depolarization

Loss of the inside/outside charge difference.

This causes axon channels to open subsequently. The temporary inflow of positive ions is the neural impulse—the action potential.

Refractory period

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 nothing principle

A neuron’s reaction of either firing or not firing.

Synapse

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

Neurotransmitters

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

Reuptake

A neurotransmitter’s reabsorption by the sending neuron

Acetylcholine (ACh)

Function: enables muscle action, learning, and memory.

Examples of malfunction: With Alzheimer’s disease, ACh producing neurons deteriorate.

When ACh is released to our muscle cell receptors, the muscle contracts. If ACh transmission is blocked, the muscles cannot contract and we become paralyzed.

Dopamine

Function: influences movement, learning, attention, and emotion.

Malfunctions: Oversupply linked to schizophrenia. Undersupply linked to tremors and decreased mobility in Parkinson’s disease.

Serotonin

Function: affects mood, hunger, sleep, and arousal.

Malfunctions: undersupply linked to depression. Some drugs that raise serotonin levels are used to treat depression.

Norepinephrine

Function: helps control alertness and arousal.

Malfunction: Undersupply can depress mood.

GABA (gamma-aminobutyric acid)

Function: a major inhibitory neurotransmitter.

Malfunction: undersupply linked to seizures, tremors, and insomnia.

Glutamate

Function: a major excitatory neurotransmitter; involved in memory.

Malfunction: oversupply can overstimulate the brain, producing migraines or seizures.

Endorphins

Function: neurotransmitters that influence the perception of pain or pleasure.

Malfunction: oversupply with opiate drugs can suppress the body’s natural endorphin supply.

“Morphine within”—natural opiate-like neurotransmitter linked to pain control and to pleasure.

Agonist

A molecule that increases a neurotransmitter’s action.

Some agonists may increase the production or release of a neurotransmitter, or block reuptake in the synapse. Other agonists may be similar enough to a neurotransmitter to bind to its receptor and mimic its excitatory or inhibitory effects. 

Some opiate drugs are agonists and produce a temporary “high” by amplifying normal sensations of arousal or pleasure.

Antagonists

A molecule that inhibits or blocks a neurotransmitter’s action.

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

The brain and spinal cord.

The spinal cord part of the CNS is a two-way information highway connecting the peripheral nervous system and the brain. Ascending neural fibers send up sensory information, and descending fibers send back motor-control information.

Peripheral nervous system

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

Nerves

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

Sensory neurons

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

These are afferent.

Motor neurons

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

These are efferent.

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 muscles of the internal organs. Its sympathetic division arouses; its parasympathetic division calms.

Sympathetic nervous system

The division of the autonomic 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.

Reflexes

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

A simple spinal reflex pathway is composed of a single sensory neuron and a single motor neuron. These often communicate through a motor neuron.

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.

Influence our interest in sex, food, and aggression.

Endocrine messages tend to outlast the effects of neural messages.

Adrenal glands

A pair of endocrine glands that sit just above the kidneys and secrete hormones—epinephrine (adrenaline) and norepinephrine (noradrenaline)—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 gland regulates growth and controls other endocrine glands.

Hormones released include a growth hormone that stimulates physical development, and oxytocin.

Feedback system: brain → pituitary → other glands → hormones → body and brain

Lesion

Tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue.

Electroencephalogram (EEG)

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.

Magnetoencephalography (MEG)

A brain imaging technique that measures magnetic fields from the brain’s natural electrical activity.

PET scan

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

MRI

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. fMRI scans show brain function as well as structure.

Brain stem

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

Medulla

Base of the brain stem; controls heartbeat and breathing.

Thalamus

The brain’s sensory control center, located on top of the brain stem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.

Receives information from all senses but smell.

Reticular formation

A nerve network that travels through the brain stem into the thalamus and plays an important role in controlling arousal.

Cerebellum

The “little brain” at the rear of the brain stem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory.

Limbic system

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

Amygdala

Two lima-bean-shaped neural clusters in the limbic system; linked to emotion.

Hypothalamus

A neural structure lying below the thalamus; it directs several maintenance activities, helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

Hippocampus

A neural center, located in the limbic system; helps process explicit (conscious) memories—of facts and events—for storage.

Cerebral cortex

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

Frontal lobes

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

Parietal lobes

the 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

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

temporal lobes

the 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

an 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

neurogenesis (ap: brain plasticity)

the formation of new neurons

corpus callosum

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

split brains

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

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)

selective attention

the focusing of conscious awareness on a particular stimulus

inattentional blindness

failing to see visible objects when our attention is directed elsewhere

change blindness

failing to notice changes in the environment; a form of inattentional blindness

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 simultaneously; the brain’s natural mode of information processing for many functions

sequential processing

processing one aspect of a 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

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

EEG patterns of REM sleep

Suprachiasmatic nucleus (SCN)

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

insomnia

Ongoing difficulty falling or staying asleep.

effects: Chronic tiredness. Reliance on sleeping pills and alcohol, which reduce REM sleep and lead to tolerance—a state in which increasing doses are needed to produce an effect.

narcolepsy

Sudden attacks of overwhelming sleepiness

Effects: Risk of falling asleep at a dangerous moment. Narcolepsy attacks usually last less than 5 minutes, but they can happen at the worst and most emotional times. Everyday activities, such as driving, require extra caution.

sleep apena

Stopping breathing repeatedly while sleeping.

Fatigue and depression (as a result of slow-wave sleep deprivation). Associated with obesity (especially among men).

sleepwalking/sleeptalking

Doing normal waking activities (sitting up, walking, speaking) while asleep. Sleeptalking can occur during any sleep stage. Sleepwalking happens in NREM-3 sleep.

REM rebound

the tendency for REM sleep to increase following REM sleep deprivation

Freud’s wish fulfillment

Dreams provide a “psychic safety valve”—expressing otherwise unacceptable feelings; contain manifest (remembered) content and a deeper layer of latent content (a hidden meaning).

critical considerations: Lacks any scientific support; dreams may be interpreted in many different ways.

Information processing

Dreams help us sort out the day’s events and consolidate our memories.

Critical considerations: But why do we sometimes dream about things we have not experienced and about past events?

physiological function

Regular brain stimulation from REM sleep may help develop and preserve neural pathways.

critical considerations: This does not explain why we experience meaningful dreams.

activation synthesis

REM sleep triggers neural activity that evokes random visual memories, which our sleeping brain weaves into stories.

critical considerations: The individual’s brain is weaving the stories, which still tells us something about the dreamer.

cognitive development

Dream content reflects dreamers’ level of cognitive development—their knowledge and understanding. Dreams simulate our lives, including worst-case scenarios.

critical considerations: Does not propose an adaptive function of dreams.

psychoactive drugs

a chemical substance that alters perceptions and moods

substance use disorder

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

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

opiates

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

stimulant

drugs that excite neural activity and speed up body functions

nicotine

Type: stimulant

good effects: Arousal and relaxation, sense of well-being

bad aftereffects: Heart disease, cancer

cocaine

type: stimulant

good effects: Rush of euphoria, confidence, energy

bad aftereffects: Cardiovascular stress, suspiciousness, depressive crash

hallucinogens

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