Unit 1: Biological Bases of Behavior 🩻

Broca’s area

A region in the left frontal lobe associated with speech production; damage to it results in expressive aphasia.

Expressive aphasia

The loss of the ability to produce language, often resulting from damage to Broca’s area.

Wernicke’s area

A region in the left temporal lobe involved in the comprehension of language.

Receptive aphasia

The loss of the ability to understand written and spoken language, often due to damage to Wernicke’s area.

Lesions

Precise destruction of brain tissue used to study brain functions.

Brain lateralization

The concept that the two hemispheres of the brain specialize in different functions.

Computerized axial tomography (CAT or CT)

An imaging technique that uses X-rays to create two-dimensional slices of the brain.

Magnetic resonance imaging (MRI)

A technique that uses magnetic fields and radio waves to create images of the brain based on tissue density.

Electroencephalogram (EEG)

A recording of electrical activity in the brain, obtained by placing electrodes on the scalp.

Evoked potentials

Changes in electrical voltage in response to specific stimuli recorded by an EEG.

Positron emission tomography (PET)

An imaging technique that produces color images based on metabolic activity in the brain.

Functional MRI (fMRI)

An imaging technique that measures brain activity by detecting changes associated with blood flow.

Magnetoencephalography (MEG)

A technique that detects magnetic fields produced by neural activity in the brain.

Central nervous system

Made up of the brain and spinal cord.

Peripheral nervous system

Comprises the somatic and autonomic nervous systems outside the central nervous system.

Somatic nervous system

Part of the peripheral nervous system that controls voluntary movements of skeletal muscles.

Autonomic nervous system

Part of the peripheral nervous system that controls involuntary functions of internal organs.

Sympathetic nervous system

A branch of the autonomic nervous system that prepares the body for stressful situations.

Parasympathetic nervous system

A branch of the autonomic nervous system that calms the body and restores normal functions.

Spinal cord

The bundle of nerves protected by the vertebral column; connects brain to the body.

Triune brain

A model that divides the brain into three major parts: the reptilian brain, old mammalian brain, and new mammalian brain.

Gyri

The ridges or peaks on the surface of the cerebral cortex.

Sulci

The grooves or valleys on the surface of the cerebral cortex.

Convolutions

The complex patterns formed by gyri and sulci on the cerebral cortex.

Fissures

Deep grooves in the brain that separate different brain regions.

Association areas

Regions of the cerebral cortex involved in higher mental functions like thinking and memory.

Medulla oblongata

A brain structure that regulates essential autonomic functions like breathing and heart rate.

Pons

A brain structure that connects different parts of the brain and is involved in regulating sleep and arousal.

Cerebellum

A brain structure that coordinates movement, balance, and posture.

Thalamus

A brain structure that relays sensory information to the appropriate areas of the cortex.

Hypothalamus

A brain structure that regulates various autonomic functions and hormonal activities.

Hippocampus

A brain structure critical for the formation of new long-term memories.

Cerebral cortex

The outer layer of the brain responsible for higher-order cognitive functions.

Plasticity

The ability of the brain to reorganize and adapt in response to injury.

Neuron

The basic unit of structure and function in the nervous system.

Glial cells

Support cells in the nervous system that assist with nutrition, waste removal, and insulation of neurons.

Dendrites

Branching processes of a neuron that receive information.

Axon

The long, single conducting fiber that transmits signals away from the neuron's cell body.

Myelin sheath

An insulating layer around neurons that increases the speed of signal transmission.

Neurogenesis

The process of forming new neurons.

Neurotransmitters

Chemicals that transmit signals across synapses between neurons.

Dopamine

A neurotransmitter involved in movement, motivation, and reward processing.

Glutamate

A major excitatory neurotransmitter involved in learning and memory.

Serotonin

A neurotransmitter that affects mood, emotion, and sleep.

GABA

An inhibitory neurotransmitter that reduces neuronal excitability.

Norepinephrine

A neurotransmitter involved in alertness and arousal.

Agonists

Substances that mimic neurotransmitters and activate their receptors.

Antagonists

Substances that block neurotransmitter receptors and inhibit their effects.

Resting potential

The electrical charge difference across a neuron's membrane at rest.

Action potential

A rapid change in electrical charge that travels along an axon when a neuron fires.

All-or-none principle

The principle that a neuron either fires completely or not at all.

Saltatory conduction

The process by which action potentials jump from one node of Ranvier to another, increasing conduction speed.

Reflex arc

The neural pathway involved in a reflex action, including sensory, interneuron, and motor neurons.

Endocrine system

The system of glands that secrete hormones into the bloodstream to regulate bodily functions.

Hormones

Chemical messengers produced by the endocrine glands.

Pineal gland

An endocrine gland that produces melatonin, regulating sleep-wake cycles.

Pituitary gland

The master gland of the endocrine system that regulates other glands and produces various hormones.

Thyroid gland

An endocrine gland that produces hormones regulating metabolism.

Adrenal glands

Glands that produce hormones like cortisol and adrenaline in response to stress.

Ovaries

The female gonads that produce eggs and sex hormones.

Testes

The male gonads that produce sperm and sex hormones.

Nature-nurture controversy

Debate over the relative contributions of genetics (nature) and environment (nurture) to behavior.

Evolutionary psychology

The study of how evolutionary processes influence human behavior and mental processes.

Behavioral geneticists

Researchers who study the influence of genetics and environment on behavior.

Identical twins

Twins that develop from a single fertilized egg, sharing 100% of their genes.

Fraternal twins

Twins that develop from two separate eggs, sharing about 50% of their genes.

Genotype

The genetic makeup of an individual.

Phenotype

The observable expression of genes in an individual.

Dominant gene

A gene that expresses its characteristics even in the presence of other different genes.

Recessive gene

A gene that expresses its characteristics only when two of its kind are present.

Tay-Sachs syndrome

A genetic disorder that leads to progressive loss of nervous function and death in infants.

Albinism

A genetic condition characterized by lack of pigment in the skin, hair, and eyes.

Phenylketonuria (PKU)

A genetic disorder that can cause severe brain damage if untreated.

Huntington’s disease

A genetic disorder that leads to degeneration of the nervous system.

Preconscious

The level of consciousness that holds feelings and memories easily brought into awareness.

Nonconscious

Processes occurring without conscious awareness.

Unconscious

The level of consciousness that contains thoughts and feelings not accessible to conscious awareness.

Dual processing

The simultaneous processing of information at both conscious and unconscious levels.

Circadian rhythm

The body's internal clock that regulates sleep-wake cycles over a 24-hour period.

NREM sleep

Non-rapid eye movement sleep, characterized by various stages of sleep before REM.

Nightmares

Vivid and disturbing dreams that occur during REM sleep.

Lucid dreaming

The ability to be aware of and control one’s dreams.

Hypnosis

An altered state of consciousness characterized by heightened suggestibility and relaxation.

Meditation

Techniques used to focus the mind and achieve a state of calmness and tranquility.

Psychoactive drugs

Chemicals that alter perceptions, mood, and behavior by affecting the brain.

Psychological dependence

An intense desire to use a drug despite negative consequences.

Tolerance

A reduced response to a drug after repeated use.

Physiological dependence

A condition where the body adapts to a drug, leading to withdrawal symptoms without it.

Withdrawal symptoms

Physical and psychological effects experienced when stopping drug use.

Depressants

Drugs that reduce central nervous system activity and induce relaxation.

Narcotics

Pain-relieving drugs that can induce drowsiness and euphoria.

Stimulants

Drugs that increase alertness and energy by boosting central nervous system activity.

Hallucinogens

Psychoactive drugs that alter sensory perception and create hallucinations.