Unit 1 Key Terms: Biological Bases of Behavior (Myers' Psychology for the AP Course, 4e)

Vocabulary flashcards covering the key terms from Myers Unit 1 on biology, neuroscience, and sensation/perception. Each card defines a term from the notes.

nature–nurture issue

The longstanding controversy over the relative contributions of genes and experience to the development of psychological traits and behaviors; today viewed as an interaction between nature and nurture.

natural selection

The principle that inherited traits enabling an organism to survive and reproduce in a particular environment will most likely be passed on to succeeding generations.

evolutionary psychology

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

behavior genetics

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

mutation

A random error in gene replication that leads to a change.

environment

Every non genetic influence, from prenatal nutrition to experiences with people and things around us.

heredity

The genetic transfer of characteristics from parents to offspring.

genes

The biochemical units of heredity.

genome

The complete instructions for making an organism.

identical (monozygotic) twins

Individuals who developed from a single fertilized egg that split in two, creating two genetically identical organisms.

fraternal (dizygotic) twins

Individuals who developed from separate fertilized eggs; they are not genetically closer than ordinary siblings, but share a prenatal environment.

interaction

The interplay that occurs when the effect of one factor depends on another factor.

epigenetics

Above or in addition to genetics; the study of molecular mechanisms by which environments influence gene expression without a DNA change.

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 cord.

peripheral nervous system (PNS)

The sensory and motor neurons that connect the CNS to the rest of the body.

nerves

Bundled axons that form neural cables connecting the CNS 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 that communicate internally and process information between sensory inputs and motor outputs.

somatic nervous system

The division of the PNS that controls the body’s skeletal muscles.

autonomic nervous system

The part of the PNS that controls the glands and the muscles of the internal organs; its sympathetic division arouses and 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 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 faster transmission speed as neural impulses hop from node to node.

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

A brief resting pause 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 full strength or not firing at all.

synapse

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

neurotransmitters

Chemical messengers that cross the synaptic gap between neurons and influence whether the receiving neuron generates a neural impulse.

reuptake

A neurotransmitter’s reabsorption by the sending neuron.

endorphins

Molecules that act as natural, opioid-like neurotransmitters linked to pain control and pleasure.

agonist

A molecule that increases a neurotransmitter’s action.

antagonist

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

endocrine system

The body’s slow chemical communication system; glands and tissues secrete hormones into the bloodstream.

hormones

Chemical messengers manufactured by the endocrine glands that travel through the bloodstream and affect other tissues.

psychoactive drug

A chemical substance that alters the brain, causing changes in perceptions and moods.

substance use disorder

A disorder characterized by continued substance use despite 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 larger doses for the same effect.

addiction

An everyday term for compulsive substance use that continues despite harmful consequences; may be used for other compulsive behaviors.

withdrawal

Discomfort and distress following the discontinuation of an addictive drug or behavior.

barbiturates

Drugs that depress the 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 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; often similar to drug-induced hallucinations.

biological psychology

The scientific study of the links between biological (genetic, neural, hormonal) and psychological processes.

biopsychosocial approach

An integrated approach that incorporates biological, psychological, and social-cultural levels of analysis.

levels of analysis

The differing complementary views from biological to psychological to social-cultural for analyzing any 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 in the brain; may occur naturally, during surgery, or experimentally.

EEG (electroencephalogram)

An amplified recording of the waves of electrical activity sweeping across the brain’s surface, measured with electrodes 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 shows where a radioactive form of glucose goes while the brain performs a task.

MRI (magnetic resonance imaging)

A technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue; shows brain anatomy.

fMRI (functional MRI)

A technique for revealing blood flow and brain activity by comparing successive MRIs; shows brain function as well as structure.

hindbrain

Contains the medulla, pons, and cerebellum; directs essential survival functions and coordinates movement and balance.

midbrain

Located atop the brainstem; connects hindbrain with forebrain; controls some motor movement and transmits auditory and visual information.

forebrain

Includes the cerebral cortex, thalamus, and hypothalamus; manages complex cognitive activities, sensory functions, and voluntary movement.

brainstem

Central core of the brain; where the spinal cord swells as it enters the skull; automatic survival functions.

medulla

The base of the brainstem that controls heartbeat and breathing.

thalamus

The forebrain’s sensory control center; routes messages to cortex and transmits replies to cerebellum and medulla.

reticular formation

A nerve network through the brainstem into the thalamus that filters information and helps control arousal.

cerebellum

The hindbrain’s little brain; coordinates movement, balance, and nonverbal learning and memory.

limbic system

Neural system located mostly in the forebrain that includes amygdala, hypothalamus, hippocampus, thalamus, and pituitary; linked to emotions and drives.

amygdala

Two lima bean size neural clusters linked to emotion.

hypothalamus

Limbic system structure below the thalamus; maintains eating, drinking, temperature; helps govern the endocrine system and links to emotion and reward.

hippocampus

Neural center in the limbic system that helps process explicit memories for storage.

cerebral cortex

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

frontal lobes

Cerebral cortexArea behind the forehead; involved in language, movement, higher-order thinking, and executive functions.

parietal lobes

Cerebral cortex region at the top of the head toward the rear; receives sensory input for touch and body position.

occipital lobes

Cerebral cortex region at the back of the head; includes areas that receive visual information.

temporal lobes

Cerebral cortex region above the ears; includes auditory areas and language processing.

motor cortex

Cerebral cortex area at the rear of the frontal lobes that controls voluntary movements.

somatosensory cortex

Cerebral cortex area at the front of the parietal lobes that registers touch and movement sensations.

association areas

Cerebral cortex areas not involved in primary motor or sensory functions but involved in higher mental functions like learning, remembering, thinking, and speaking.

neurogenesis

The formation of new neurons.

corpus callosum

Large bundle of neural fibers connecting the two hemispheres and carrying messages between them.

split brain

A condition resulting from surgery that separates the brain’s two hemispheres by cutting the corpus callosum.

consciousness

Our subjective awareness of ourselves and our environment.

cognitive neuroscience

The interdisciplinary study of brain activity linked with cognition, including 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; used to process new information or solve difficult problems.

sleep

A periodic, natural loss of consciousness; not due to a coma, anesthesia, or hibernation.

circadian rhythm

A biological clock; regular bodily rhythms on a 24-hour cycle.

REM sleep

Rapid eye movement sleep; a stage with vivid dreams; muscles are relaxed but other systems are active.

alpha waves

Relatively slow brain waves of a relaxed, awake state.

NREM sleep

Non rapid eye movement sleep; includes all sleep stages except REM.

hallucinations

False sensory experiences, such as seeing something in the absence of an external stimulus.