AP PSYCH UNIT C

evolutionary psychology

the study of the evolution of behavior and the mind, using principles of natural selection.

natural selection

the principle that inherited traits that better enable an organism to survive and reproduce in a particular environment will (in competition with other trait variations) most likely be passed on to succeeding generations.

behavior genetics

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

heredity

the genetic transfer of characteristics from parents to offspring.

environment

every nongenetic 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 proteins.

genome

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

monozygotic twins

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

dizygotic twins

fraternal twins -develop from separate fertilized eggs. They are genetically no closer than ordinary brothers and sisters, but they share a prenatal environment.

heritability

the proportion of variation among individuals in a group that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied.

epigenetics

"above" or "in addition to" genetics; the study of environmental influences on gene expression that occur without a DNA change.

corpus callosum [KOR-pus kah-LOWsum]

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.

consciousness

our subjective awareness of ourselves and our environment.

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; generally used to process well-learned information or to solve easy problems.

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 [puh-RYE-uh-tuhl] 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 [ahk-SIP-uh-tuhl] 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.

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.

lesion

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

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.

fMRI (functional MRI)

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

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. (Also called CAT scan.)

PET scan (positron emission tomography)

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. It scans show brain anatomy.

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 [muh-DUL-uh]

the base of the brainstem; controls heartbeat and breathing.

thalamus [THAL-uh-muss]

the brain'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 and plays an important role in controlling arousal.

cerebellum [sehr-uh-BELL-um]

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.

limbic system

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

amygdala [uh-MIG-duh-la]

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

hypothalamus [hi-po-THAL-uhmuss]

a neural structure lying below 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.

hippocampus

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

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.

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 response.

endocrine [EN-duh-krin] 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.

neuron

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

dendrites

a neuron's often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body.

cell body

the part of a neuron that contains the nucleus; the cell's life support center.

axon

the 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; 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 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 [SIN-aps]

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, 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, opiate-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.

GABA

An inhibitory neurotransmitter in the brain.

Serotonin

Neurotransmitter that affects mood, hunger, sleep and arousal. Undersupply linked to depression.

Dopamine

A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system.

Epinephrine

Neurotransmitter secreted by the adrenal medulla in response to stress. Also known as adrenaline.

Norepinephrine

A neurotransmitter involved in arousal, as well as in learning and mood regulation

consciousness

our subjective awareness of ourselves and our environment.

dissociation

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

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.

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.

delta waves

the large, slow brain waves associated with the deep sleep of NREM-3.

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, night terrors occur during NREM-3 sleep, within two or three hours of falling asleep, and are seldom remembered.

manifest content

according to Freud, the symbolic, remembered story line of a dream (as distinct from its latent, or hidden, content).

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.

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 an addictive drug or behavior.

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.