AP Psych Unit 3 - Biological Bases of Behavior (Myers Textbook)

Biological Psychology

The scientific study of the links between biological (genetic, neural, hormonal) and psychological processes

Localization of Functions

The idea that various brain regions have particular functions

Neurons

A nerve cell, the basic building block of the nervous system: consists of a cell body and branching fibers

Dendrites

A neuron’s bushy branching extensions that receive messages and conduct impulses toward the cell body (Dendrites listen, axons speak\*)

Axon

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

Myelin Sheath

A fatty, tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one sausage-like node to the next; insulates axons and speeds their impulses

Action Potential

A neural impulse; a brief electrical charge that travels down an atom when stimulated neurons (by our senses or chemical signals from neighboring neurons) transmit a message

Resting Potential

Positive-outside/ negative-inside state that has mostly negative ions, whereas the fluid outside an axon’s membrane has positive ions.

Refractory Period

A period of inactivity after a neuron has fired

Threshold

The levels 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

Noticed by Sir Charles Sherrington (1852-1952); the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at the junction is called the synaptic gap or synaptic cleft

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 reabsorption by the sending neuron

Endorphine

“Morphine within”- natural opiate-like neurotransmitters linked to pain control and pleasure

Dopamine

Neurotransmitters that influence movement, learning, attention, and emotion; an oversupply is linked to schizophrenia while, an undersupply is linked to tremors and decreased mobility in Parkinson’s disease

Serotonin

Neurotransmitters that affect mood, hunger, sleep, and arousal; an undersupply is linked to depression

Acatychoine (ACh)

Neurotransmitters that enable muscle action, learning, and memory; ACh-producing neurons deteriorate with Alzheimer’s disease

Norepinephrine

Neurotransmitters that help control alertness and arousal; an undersupply can depress mood

GABA (gamma-aminobutyric acid)

A major inhibitory neurotransmitter; an undersupply is linked to seizures, tremors, and insomnia

Glutamate

A major excitatory neurotransmitter that is involved in memory; an oversupply can overstimulate the mind, producing migraines or seizures

Agonist

A molecule that, by binding to a receptor site, stimulates a response (ex. sex-arousing chocolates)

Antagonist

Molecule that by binding to a receptor site, inhibits or blocks a response (ex. Botox or paralysis poison)

Nervous System

The body’s speedy, electrochemical communication network, consisting of all the nerve cells at the peripheral and central nervou system

Central Nervous System (CNS)

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

Peripheral Nervous System (PNS)

The sensory and motor neurons responsible for gathering information and transmitting CNS decisions to other body parts

Nerves

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

Sensory (afferent) Neurons

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

Motor (efferent) Neurons

Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

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 (ANS)

Part of the peripheral nervous system that controls the glands and muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms

Sympathetic Nervous System

The division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations; dilates pupils, accelerates heartbeat, inhibits digestion

Parasympathetic Nervous System

The division of the autonomic nervous system that calms the body, conserving its energy; contracts pupils, slows heartbeat, stimulates digestion

Neural Network

Neurons in the brain connect with one another to form networks

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 that are manufactured by the endocrine gland travel through the bloodstream and affect other tissues

Adrenal Gland

A pair of endocrine glands that sit just above the kidneys and secret hormone (epinephrine and norepinephrine) that help arouse the body in times of stress

Pituitary Gland

The endocrine system’s most influential gland; under the influence of the hypothalamus, the pituitary regulates growth and control other endocrine glands

Lesion

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

Electroencephalogram (EEG)

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 (computed tomography) Scan

A series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slide of the brain’s structure; also called at CAT scan

PET (positron emission tomography) Scan

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

MRJ (magnetic resonance imaging)

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

fMRI (functional MRI)

A technique for revealing blood flow and, therefore, brain activity by comparing successive MRI 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 and it enters the skull; the brainstem is responsible for automatic survival functions

Medulla

The base of the brainstem; controls heartbeat and breathing

Pons

Just above the medulla, the pons help coordinate movements

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

Between your ears, a nerve network that travels through the brainstem and thalamus, and plays an important role in controlling arousal

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

Cerebral Hemisphere

Two halves of the brain

Limbic System

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

Hippocampus

A curved tube in the limbic system that processes conscious memories. Without it, we lose our ability to form new memories of facts and events

Amygdala

Two lima-bean-sized neural clusters in the limbic system; linked to emotion (aggression and fear)

Hypothalamus

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

Reward Deficiency Syndrome

Craving whatever provides that missing pleasure or relieves negative feelings

Cerebrum

Hemispheres that contribute 85% of the brain’s weight; forms specialized work teams that enable our perceiving, thinking, and speaking

Cerebral Cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information-processing center. It contains some 20-30 billion nerve cells and 300 trillion synaptic connections

Glial Cells (Glia)

Cells in the nervous system that support, nourish, and protect neurons; they may also play a role in learning and thinking; they insulate myelin, guide neural connections, and map up ions and neurotransmitters

Frontal Lobe

Portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle memory, and in making plans and judgments; damage to it can alter personality or remove a persons inhibitions (moral compass)

Parietal Lobes

Portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position

Occipital Lobes

Portion of the cerebral cortex, lying at the back of the head; included areas that receive information from the visual fields

Temporal Lobes

Portion of the cerebral cortex lying roughly above the ears; includes the auditory area, each receiving information primarily from the opposite eat

Motor Cortex

An area at the rear of the frontal lobes that controls voluntary precise controls; the fingers and mouth occupy the greatest amount of cortical space

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

Prefrontal Cortex

Forward part of the frontal lobes that enables judgment, planning, and processing of new memories

Broca’s Area

In the frontal cortex; disrupts speaking

Wernicke’s Area

Close to the auditory cortex; disrupts understanding

Plasticity

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

Neurogenesis

Process in which the brain sometimes mends itself by forming new neurons

Corpus Callosum

The large band of neural fibers connecting the two brain hemispheres and carrying messages between them

Spilt 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; leaves people with “two seperate minds”

Consciousness

Our awareness of ourselves and our enviroment

Cognitive Neuroscience

The interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language)

Dual Processing

The principle that information is often simultaneously processed on separate conscious and unconscious tracks

Behavior Genetics

The study of the relative power and limits of genetic and environmental influences on behavior

Enviroment

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

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. However, twins don’t always have the same number of gene copies and 1/3 sets of twins have two separate placentas so, one twin may be more nourished

Fraternal 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; seeks to identify specific genes influencing behavior

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; the extent to which differences among people are attributed to genes

Interaction

The interplay that occurs when the effect of one factor (such as environmental) depends on another factor (such as hereditary)

Epigenetics

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

Evolutionary Psychology

The study of the evolution of behavior and the mind, using principles of natural selection

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

Bad Faith

Attributing responsibility for one’s fate to bad genes or bad influences; coined by Jean-Paul Sartre