AP Psychology - Neuroscience

Biological Psychology

Study of connections between biological and psychological systems.

Neuron

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

Dendrite

Bushy fibers receive information and conduct it toward the cell body.

Axon

The neuron extension that passes messages through its branches to other neurons or to muscles or glands.

Myelin sheath

Layer of fatty tissue that insulates them and speeds their impulses.

Action potential

A neural impulse; a brief electrical charge that travels down an axon.

Refactory period

A period of inactivity after a neuron has fired.

Threshold

The level of stimulation required to trigger a neural impulse.

All-or-None response

A neuron’s reaction of either firing (with a full-strength response) or not firing.

Synapse

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

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.

Reuptake

A neurotransmitter’s re-absorption by the sending neuron.

Endorphins

“morphine within”—natural, opiate-like neurotransmitters linked to pain control and to pleasure.

Agonist

Similar enough to a neurotransmitter to bind to its receptor and mimic its effects.

Antagonist

Bind to receptors but their effect is instead to block a neurotransmitter’s functioning.

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

The brain and spinal cord.

Peripheral nervous system.

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

Nerves

Bundled axons that form neural “cables” connecting the central nervous system with muscles, glands, and sense organs.

Sensory (Afferent) Neurons

Nerve fibers responsible for bringing sensory information from the outside world into the brain.

Motor (Efferent) Neurons

The nerve fibers responsible for carrying signals from the brain to the peripheral nervous system in order to initiate an action.

Interneurons

Neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs.

Somatic Nervous System

The division of the peripheral nervous system that controls the body’s skeletal muscles. (Also called the skeletal nervous system.)

Autonomic Nervous System

Controls our glands and the muscles of our internal organs, influencing such functions as glandular activity, heartbeat, and digestion.

Sympathetic Nervous System

The division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.

Parasympathetic Nervous System

The division of the autonomic nervous system that calms the body, conserving its energy.

Reflex

Our automatic responses to stimuli, illustrate the spinal cord’s work.

Endocrine System

Glands secrete another form of chemical messengers, hormones, which travel through the bloodstream and affect other tissues, including the brain.

Hormones

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

Adrenal Gland

Top of the kidneys. Release epinephrine and norepinephrine (also called adrenaline and noradrenaline). These hormones increase heart rate, blood pressure, and blood sugar, providing us with a surge of energy, known as the fight-or-flight response. When the emergency passes, the hormones—and the feelings of excitement—linger a while.

Pituitary Gland

The endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

Lesion

Tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue.

Electroencephalogram

An amplified recording of the waves of electrical activity sweeping across the brain’s surface. These waves are measured by electrodes placed on the scalp.

CT 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. (Also called CAT scan.)

PET Scan

A visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task.

MRI

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

fMRI

A technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as its structure.

Brainstem

The oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions.

Medulla

The base of the brainstem; controls heartbeat and breathing.

Thalamus

The brain’s sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.

Reticular Formation

Neuron network that extends from the spinal cord right up through the thalamus. As the spinal cord’s sensory input flows up to the thalamus, some of it travels through the reticular formation, which filters incoming stimuli and relays important information to other brain areas.

Cerebellum

The “little brain” at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory.

Limbic System

Neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.

Amygdala

Two lima-bean-sized neural clusters in the limbic system; linked to emotion.

Hypothalamus

A neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

Cerebral Cortex

Thin layer of neural connections encompassing the cerebral hemispheres. (Center of thinking)

Glial Cells

Maintains a neuron's myelin and manages excess ions and neurotransmitters.

Frontal Lobes

Front of the brain. Communication, motion, and decision making.

Parietal Lobes

Upper back of the brain. Gathers psychical senses and spatial orientation.

Occipital Lobes

Lower back of the brain. Gathers visual information.

Temporal Lobe

Right above the ears. Receives information from the opposite ear.

Motor Cortex

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

Somatosensory Cortex

Area at the front of the parietal lobes that registers and processes body touch and movement sensations.

Association Areas

Areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking.

Plasticity

The brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.

Neurogenesis

Brain attempts to mend itself by producing new brain cells. Instead of reorganizing tissue.

Corpus Callosum

The 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 brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.

Consciousness

Our awareness of ourselves and our environment.

Behavior Geneticists

Who study our differences and weigh the effects and interplay of heredity and environment.

Environment

Every external influence, from prenatal nutrition to the people and things around us.

Chromosome

The plans for your own book of life run to 46 chapters—23 donated by your mother’s egg and 23 by your father’s sperm.

DNA (deoxyribonucleic acid)

A complex molecule containing the genetic information that makes up the chromosomes.

Genes

The biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins.

Genome

The complete instructions for making an organism, consisting of all the genetic material in that organism’s chromosomes.

Identical twins (monozygotic twins)

Twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms.

fraternal twins (dizygotic twins)

Twins who develop from separate fertilized eggs. They are genetically no closer than brothers and sisters, but they share a fetal environment.

Molecular genetics

The subfield of biology that studies the molecular structure and function of genes.

Heritability

The proportion of variation among individuals that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied.

Epigenetics

The study of environmental influences on gene expression that occur without a DNA change.

Interaction

Genes and experience both interact.

Natural selection

The principle that, among the range of inherited trait variations, those contributing to reproduction and survival will most likely be passed on to succeeding generations.

Mutation

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