Comprehensive Neurobiology and Psychology Key Terms for Students

Ablation / Lesioning

Intentionally destroying brain tissue to study how behavior changes.

Accommodation

The process of the eye's lens changing shape to focus on near or far objects.

Acetylcholine (ACh)

A neurotransmitter that enables muscle action, learning, and memory.

Action Potential

A brief electrical impulse that travels down a neuron's axon.

Addiction

Compulsive drug craving and use, despite negative consequences.

Adoption Studies

Comparing adopted children to both biological and adoptive parents to study nature vs. nurture.

Adrenaline

A hormone triggering the fight-or-flight response during stress.

Afferent Pathways / Sensory Neurons

Nerves carrying signals inward from the body to the brain.

Agonist

A chemical or drug that mimics a neurotransmitter to trigger a response.

Alcohol

A common depressant drug that slows down brain activity and body functions.

All-or-Nothing Principle

A neuron either fires completely or does not fire at all; there is no 'half-fire.'

Amygdala

The brain's emotion center, primarily responsible for fear and aggression.

Angiogram

An X-ray technique using dye to map the blood vessels in the brain.

Antagonist

A chemical or drug that blocks a neurotransmitter from working.

Aphasia

An impairment of language, usually due to brain damage.

Aqueous (Humor)

The clear, watery fluid filling the front chamber of the eye.

Association Areas

Parts of the cerebral cortex responsible for higher mental functions like learning and thinking.

Auditory Canal

The tunnel in the ear that channels sound waves to the eardrum.

Autonomic Nervous System

The part of the nervous system controlling involuntary actions (like heartbeat).

Axon

The long tail of a neuron that sends messages away from the cell body.

Axon Hillock

The base of the axon where the action potential is generated.

Behaviorism

A psychological approach focusing only on observable behaviors and learning.

Biological / Physiological Approach

Explains behavior through genetics, brain chemistry, and hormones.

Biopsychosocial Approach

Explains behavior by combining biology, psychology, and social environment.

Bottom-Up Processing

Building a perception purely from raw sensory details, without prior knowledge.

Brain Stem

The oldest part of the brain; controls automatic survival functions.

Broca's Area

The brain area (usually left frontal lobe) that controls speaking and language expression.

Caffeine

A mild, widely used stimulant drug.

Cell Body (Soma)

The life-support center of a neuron.

Central Nervous System (CNS)

The brain and the spinal cord.

Cerebellum

The 'little brain' responsible for balance, coordination, and muscle memory.

Cerebral Cortex

The wrinkled outer layer of the brain where complex thinking occurs.

Change Blindness

Failing to notice visual changes in the environment.

Cocaine

A powerful, highly addictive stimulant drug.

Cognitivism

A psychological approach focusing on mental processes like memory, thinking, and problem-solving.

Computed Tomographic (CT) Scan

A 3D X-ray image of the brain's structure.

Conduction Hearing Loss

Deafness caused by physical damage to the eardrum or ear bones.

Cones

Eye receptor cells that detect color and fine detail in daylight.

Contralateral Organization

The left side of the brain controls the right side of the body, and vice versa.

Cornea

The clear, protective outer layer of the eye.

Corpus Callosum

The thick band of nerve fibers connecting the left and right brain hemispheres.

Dendrites

The branch-like parts of a neuron that receive messages.

Depolarization

The chemical shift inside a neuron (becoming positive) that causes it to fire.

Depressants

Drugs that slow down neural activity and body functions.

Detection

The basic ability to notice that a stimulus is present.

Discrimination

The ability to tell the difference between two similar stimuli.

Dopamine

A neurotransmitter linked to reward, pleasure, and movement.

EEG (Electroencephalogram)

A recording of electrical brain waves via electrodes on the scalp.

Efferent Pathways / Motor Neurons

Nerves carrying signals outward from the brain to the muscles.

Endocrine System

The body's system of glands that secrete hormones into the bloodstream.

Endorphins

The body's natural painkilling and pleasure-producing neurotransmitters.

ESB (Electrical Stimulation of the Brain)

Sending a mild current into the brain to trigger or study behavior.

Eugenics

The controversial study of selectively breeding humans to improve genetic traits.

Evolutionary Perspective

Explains human behavior as traits that helped our ancestors survive and reproduce.

Excitatory Neurotransmitters

Chemicals that encourage the next neuron to fire.

Executive Functioning

Higher-level cognitive skills like planning, focusing, and controlling impulses.

Family Studies

Examining blood relatives to see how much a specific trait runs in a family.

fMRI (Functional MRI)

A scan that shows both brain structure and activity by tracking blood flow.

Fovea

The central focal point of the retina, containing only cones for sharp vision.

Frontal Lobes

The brain lobes behind the forehead involved in speaking, planning, and judgment.

GABA

The brain's major inhibitory neurotransmitter (calms things down).

Genetic Predisposition

An inherited likelihood of developing a certain trait or disease.

Ghrelin

The hormone that signals you are hungry.

Glial Cells

Support cells that feed, protect, and insulate neurons.

Glutamate

The brain's major excitatory neurotransmitter, involved in memory.

Gustatory Cortex

The brain area responsible for processing the sense of taste.

Hallucinogens

Drugs that distort perception and trigger fake sensory images (hallucinations).

Hemispheric Specialization

The fact that the left and right sides of the brain have different strengths.

Heredity

The genetic passing of traits from parents to offspring.

Heroin

A highly addictive opioid drug used for severe pain relief and euphoria.

Hertz

The unit used to measure sound frequency (pitch).

Higher-Order Thinking

Complex critical thinking, such as analyzing and evaluating information.

Hippocampus

The brain structure that processes and stores new explicit memories.

Hormones

Chemical messengers created by the endocrine glands.

Humanism

A psychological approach focusing on free will, human potential, and self-actualization.

Hypothalamus

The brain structure that regulates hunger, thirst, body temperature, and the endocrine system.

Inattentional Blindness

Failing to see visible objects when your attention is focused elsewhere.

Inhibitory Neurotransmitters

Chemicals that prevent the next neuron from firing.

Interneurons

Neurons in the brain/spinal cord that communicate between sensory and motor neurons.

Iris

The colored muscle of the eye that expands or shrinks the pupil.

Just Noticeable Difference (JND)

The smallest difference you can detect between two stimuli 50% of the time.

Kinesthetic Sense

Your awareness of the position and movement of your body parts.

Lens

The clear eye structure that focuses light onto the retina.

Leptin

The hormone that signals you are full.

Limbic System

The brain's emotion and drive center (contains amygdala, hypothalamus, hippocampus).

Linguistic Processing

The mental process of using grammar and vocabulary to understand or produce language.

Marijuana

A mild hallucinogen that alters perception and relaxes the user.

Medulla

The base of the brainstem that controls heartbeat and breathing.

Melatonin

The hormone that regulates the sleep-wake cycle.

Motor Cortex

The strip at the back of the frontal lobes that controls voluntary movement.

MRI (Magnetic Resonance Imaging)

A scan using magnetic fields to create a highly detailed image of brain tissue.

Multiple Sclerosis

A disease caused by the destruction of the myelin sheath around neurons.

Myasthenia Gravis

An autoimmune disease that weakens voluntary muscles.

Myelin / Myelin Sheath

The fatty insulation around an axon that speeds up neural signals.

Natural Selection

The evolutionary process where beneficial traits survive and are passed on.

Nature

The influence of inherited genetics on your behavior and traits.

Neural Pathways / Transmission

The electrochemical communication network between neurons.

Neural Threshold

The minimum amount of stimulation a neuron needs to trigger an action potential.

Neurogenesis

The brain's ability to grow new neurons.

Neuron

A single nerve cell.