APPsych UNIT 1 VOCAB

nature–nurture issue

The debate over the relative contributions of genetics (nature) and environment (nurture) to human development.

Charles Darwin

The scientist who proposed the evolutionary process of natural selection.

natural selection

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

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

Random errors in gene replication that become nature’s preliminary tests of alternative possibilities.

environment

Every nongenetic influence from prenatal nutrition to our experiences of the people and things around us.

heredity

The genetic transfer of characteristics from parents to offspring.

genes

Small segments of DNA molecules.

genome

The complete instruction 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, genetically no closer than ordinary siblings.

interaction

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

epigenetics

The study of the molecular mechanisms by which environments can influence genetic expression.

nervous system

The body's speedy electrochemical messaging system.

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 to the CNS.

motor (efferent) neurons

Neurons that carry outgoing information from the CNS to the muscles and glands.

interneurons

Neurons within the brain and spinal cord that communicate internally and process information.

somatic nervous system

Enables voluntary control of skeletal muscles.

autonomic nervous system (ANS)

Controls our glands and internal organ muscles.

sympathetic nervous system

The division of the autonomic nervous system that arouses the body.

parasympathetic nervous system

The division of the autonomic nervous system that calms the body.

reflex

Automatic and involuntary responses to stimuli.

neuron

Nerve cells.

cell body

The cell’s life-support center.

dendrites

Branching extensions that receive and integrate messages toward the cell body.

axon

The segmented neuron extension passing messages to other neurons or muscles.

myelin sheath

A layer of fatty tissues that segments axons of some neurons.

glial cells (glia)

Cells that support, nourish, and protect neurons.

action potential

A neural impulse 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.

all-or-none response

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

synapse

The junction between the axon tip of a sending neuron and the dendrite or cell body of a receiving neuron.

neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons.

reuptake

The process where excess neurotransmitters are reabsorbed by the sending neuron.

endorphins

Natural, opioid-like neurotransmitters linked to pain control and pleasure.

agonist

A molecule that increases a neurotransmitter’s action.

antagonist

A molecule that decreases a neurotransmitter’s action.

endocrine system

The body’s slow chemical communication system using hormones.

hormones

Chemical messengers manufactured by the endocrine glands.

psychoactive drug

A chemical substance that alters brain function.

substance use disorder

A disorder characterized by continued substance use despite significant disruption.

depressants

Drugs that calm neural activity and slow body functions.

tolerance

A diminished response to a drug after repeated use.

addiction

A chronic, relapsing disorder characterized by compulsive drug seeking.

withdrawal

Symptoms that occur when a person stops using an addictive substance.

barbiturates

Drugs that reduce anxiety and tension.

opioids

Drugs that temporarily lessen pain and anxiety.

stimulants

Drugs that excite neural activity and speed up body functions.

hallucinogens

Drugs that distort perceptions and evoke sensory images.

near-death experience

An altered state of consciousness often reported by people who have come close to death.

biological psychology

The scientific study of the links between biological and psychological processes.

biopsychosocial approach

An integrated approach that incorporates biological, psychological, and social cultural factors.

neuroplasticity

The brain’s ability to change and adapt based on experience.

lesion

Tissue destruction.

EEG (electroencephalogram)

An amplified recording of electrical activity in the brain.

MEG (magnetoencephalography)

Measures magnetic fields from the brain's activity.

CT (computed tomography) scan

A series of X-ray photographs of the brain.

PET (positron emission tomography)

A scan that shows brain activity by tracking glucose consumption.

MRI (magnetic resonance imaging)

A technique using magnetic fields and radio waves to produce images.

fMRI (functional MRI)

A technique for revealing blood flow and brain activity.

hindbrain

Contains structures that control essential survival functions.

midbrain

Connects the hindbrain and forebrain; controls some movement.

forebrain

Processes information related to complex cognitive activities.

brainstem

The brain’s innermost region controlling basic life functions.

medulla

The slight swelling in the spinal cord at the skull's entry.

thalamus

The brain’s sensory control center.

reticular formation

A nerve network that filters information and controls arousal.

cerebellum

Enables nonverbal learning and skill memory.

limbic system

Associated with emotions, drives, and memory formation.

amygdala

Enables aggression and fear responses.

hypothalamus

Governs bodily maintenance and links to emotion and reward.

hippocampus

Processes explicit memories for storage.

cerebral cortex

The ultimate control and information-processing center of the body.

frontal lobes

Enable higher-order thinking and muscle movement.

parietal lobes

Receives sensory input for touch and body position.

occipital lobes

Receive visual information.

temporal lobes

Auditory areas that process sound information.

motor cortex

Controls voluntary movements, located in the frontal lobes.

somatosensory cortex

Processes touch and pain sensation.

association areas

Integrate information from different sensory areas.

neurogenesis

The process of producing new neurons.

corpus callosum

The large band of neural fibers connecting the two hemispheres.

Roger Sperry

Psychologist known for his work on split-brain research.

Michael Gazzaniga

Psychologist known for his research on split-brain theory.

split brain

A condition resulting from surgery that separates the brain's hemispheres.

consciousness

An individual’s awareness of their unique thoughts and sensations.

cognitive neuroscience

The study of the brain activity linked with cognition.

dual processing

Information processed simultaneously on conscious and unconscious tracks.

blindsight

Responding to visual stimuli without conscious awareness.

parallel processing

Processing multiple aspects of a stimulus simultaneously.

sequential processing

Processing one aspect of a stimulus at a time.

sleep

A periodic, natural loss of consciousness.

circadian rhythm

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

REM sleep

Rapid Eye Movement sleep, a stage where vivid dreams occur.

alpha waves

Slow brain waves of a relaxed, awake state.