The Biology of Behavior and Consciousness – Key Vocabulary

Flashcards cover essential vocabulary from the lecture notes on neural communication, nervous and endocrine systems, brain structures, consciousness, sleep, and dreams.

Plasticity

The brain’s ability to change by reorganizing pathways or building new ones based on experience.

Neuron

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

Cell Body

The part of a neuron containing the nucleus; the cell’s life-support center.

Dendrites

Neuron extensions that receive and integrate messages, conducting them toward the cell body.

Axon

The neuron extension that sends messages to other neurons or to muscles and glands.

Action Potential

A brief electrical charge that travels down an axon; the neuron’s nerve impulse.

Glial Cells (Glia)

Supportive nervous-system cells that nourish neurons, produce myelin, guide connections, and aid learning, thinking, and memory.

Synapse

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

Threshold

The level of stimulation required to trigger a neural impulse.

Refractory Period

A brief resting pause after a neuron fires; new action potentials cannot occur until the axon resets.

All-or-None Response

A neuron’s reaction of either firing with full strength or not firing at all.

Neurotransmitters

Chemicals produced by neurons that cross the synaptic gap to carry messages to other cells.

Reuptake

The reabsorption of a neurotransmitter by the sending neuron after signaling.

Opiate

A chemical such as opium, morphine, or heroin that lessens pain and anxiety by depressing neural activity.

Endorphins

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

Nervous System

The body’s speedy electrochemical communication network consisting of all nerve cells of the central and peripheral nervous systems.

Central Nervous System (CNS)

The brain and spinal cord; the body’s decision maker.

Peripheral Nervous System (PNS)

Sensory and motor neurons connecting the CNS to the rest of the body.

Nerves

Bundles of axons that form neural cables linking the CNS with muscles, glands, and sense organs.

Sensory Neurons

Neurons that carry incoming information from sensory receptors to the brain and spinal cord.

Motor Neurons

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

Interneurons

CNS neurons that communicate internally and process information between sensory inputs and motor outputs.

Somatic Nervous System

PNS division controlling the body’s skeletal muscles (skeletal nervous system).

Autonomic Nervous System (ANS)

PNS division that controls glands and internal-organ muscles; includes sympathetic and parasympathetic divisions.

Sympathetic Nervous System

ANS subdivision that arouses the body and mobilizes its energy in stressful situations.

Parasympathetic Nervous System

ANS subdivision that calms the body and conserves its energy.

Reflex

A simple, automatic response to a sensory stimulus, such as the knee-jerk response.

Endocrine System

The body’s slow chemical communication system; a set of glands that secrete hormones into the bloodstream.

Hormones

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

Adrenal Glands

Endocrine glands above the kidneys that secrete epinephrine and norepinephrine to arouse the body in stress.

Pituitary Gland

The most influential endocrine gland; under hypothalamus control it regulates growth and other endocrine glands.

EEG (Electroencephalograph)

A device that records electrical activity waves sweeping across the brain’s surface via scalp electrodes.

MEG (Magnetoencephalography)

A brain-imaging technique that measures magnetic fields from the brain’s natural electrical activity.

PET Scan

Positron emission tomography; shows brain activity by tracking radioactive glucose as the brain performs a task.

MRI

Magnetic resonance imaging; uses magnetic fields and radio waves to produce images of brain anatomy.

fMRI

Functional MRI; reveals blood-flow changes to show brain function as well as structure.

Brainstem

The oldest and innermost brain region; responsible for automatic survival functions.

Medulla

The base of the brainstem controlling heartbeat and breathing.

Thalamus

The brain’s sensory control center atop the brainstem; it directs messages to sensory-receiving areas and transmits replies.

Reticular Formation

A nerve network traveling through the brainstem into the thalamus; important for arousal and filtering stimuli.

Cerebellum

The ‘little brain’ at the rear of the brainstem; coordinates movement, balance, and nonverbal learning and memory.

Limbic System

Neural system including the amygdala, hypothalamus, and hippocampus; associated with emotions and drives.

Amygdala

Two lima-bean-sized neural clusters in the limbic system linked to emotion, especially fear and aggression.

Hypothalamus

A limbic structure below the thalamus that directs maintenance activities and governs the endocrine system via the pituitary; linked to emotion and reward.

Hippocampus

A limbic system structure that processes conscious, explicit memories of facts and events.

Cerebral Cortex

The thin layer of interconnected neurons covering the cerebral hemispheres; the body’s ultimate control and information-processing center.

Frontal Lobes

Cerebral cortex portion behind the forehead involved in speaking, muscle movements, planning, and judgment.

Parietal Lobes

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

Occipital Lobes

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

Temporal Lobes

Cortex region roughly above the ears; includes auditory areas receiving information from the opposite ear.

Motor Cortex

Rear area of the frontal lobes controlling voluntary movements.

Somatosensory Cortex

Front area of the parietal lobes that registers and processes body touch and movement sensations.

Association Areas

Cerebral cortex regions involved in higher mental functions such as learning, remembering, thinking, and speaking.

Neurogenesis

The formation of new neurons in the brain.

Corpus Callosum

A 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 hemispheres by cutting the corpus callosum fibers.

Biological Psychology

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

Cognitive Neuroscience

Interdisciplinary study of the brain activity linked with cognition (perception, thinking, memory, language).

Consciousness

Our subjective awareness of ourselves and our environment.

Sequential Processing

Processing one aspect of a stimulus or problem at a time; used for new or complex tasks.

Parallel Processing

Processing many aspects of a stimulus simultaneously; the brain’s natural mode for routine functions.

Selective Attention

Focusing conscious awareness on a particular stimulus while ignoring others.

Inattentional Blindness

Failure to see visible objects when our attention is directed elsewhere.

Change Blindness

Failure to notice changes in the environment when attention is elsewhere.

Circadian Rhythm

Our internal 24-hour biological clock regulating sleep-wake cycles and other bodily rhythms.

Sleep

A periodic, natural loss of consciousness distinct from coma, anesthesia, or hibernation.

REM Sleep

Rapid eye movement sleep; a recurring sleep stage with vivid dreams and muscle paralysis (paradoxical sleep).

Alpha Waves

Relatively slow brain waves of a relaxed, awake state.

Delta Waves

Large, slow brain waves associated with deep N3 sleep.

Suprachiasmatic Nucleus (SCN)

Cell clusters in the hypothalamus that control circadian rhythm by regulating melatonin production.

Insomnia

Recurring problems in falling or staying asleep.

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks, sometimes directly into REM sleep.

Sleep Apnea

A disorder in which a sleeping person repeatedly stops breathing until blood oxygen drops and awakens them.

Night Terrors

High-arousal sleep disorders occurring during N3 sleep, involving terrified appearances and seldom remembered.

Dream

A sequence of images, emotions, and thoughts occurring during sleep, most vivid in REM sleep.

Manifest Content

According to Freud, the remembered storyline of a dream.

Latent Content

According to Freud, the underlying meaning of a dream.

REM Rebound

The tendency for REM sleep to increase following REM-sleep deprivation.