ap psychology unit 1 vocab : biological bases of behavior

central nervous system (CNS)

division of the nervous system that consists of the brain and spinal cord. (p. 92)

peripheral nervous system (PNS)

the sensory and motor neurons that connect the CNS to the rest of the body. (p. 92)

somatic nervous system

division of the peripheral nervous system that controls the body's skeletal muscles; also called the skeletal nervous system. (p. 93)

neuron

a nerve cell; basic (building block) cell of the nervous system. (p. 81)

sensory (afferent) neurons

neurons that carry information from the receptors (from the body’s tissues & sensory receptors) to the spinal cord and brain. (p. 93)

motor (efferent) neurons

neurons that carry information from the brain and spinal cord to the muscles & glands. (p. 93)

autonomic nervous system (ANS)

division of the peripheral nervous system involved in the control of (generally unconscious/automatic) bodily functioning through organs and glands; its sympathetic division arouses while the parasympathetic division calms. (p. 93)

sympathetic nervous system

subdivision of the autonomic nervous system responsible for mobilizing the body in times of stress, and preparing for flight or fight. (p. 93)

parasympathetic nervous system

subdivision of the autonomic nervous system responsible for calming the body, and conserving its energy. (p. 93)

reverses the effects of the sympathetic NS, think “rest & digest”.

reflex

automatic behavior in response to a specific sensory stimulus (ex. knee-jerk response); does not involve communication with the brain. (p. 94)

brainstem

the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; responsible for automatic survival functions and composed of medulla, pons, and reticular formation. (p. 102)

medulla

base of the brainstem; controls heartbeat & breathing. (p. 102)

reticular formation

a nerve network that runs through the center of the brain stem; important in controlling arousal levels. (p. 102)

cerebellum

the “little brain” at the rear of the brainstem; functions include processing sensory input, coordinating mvmt output & balance, & enabling nonverbal learning & memory. (p. 103)

corpus callosum

the large band of neural fibers that connects the two hemispheres of the brain & carries messages between them. (p. 120)

limbic system

a group of structures located beneath the cerebral cortex that are involved in regulating emotions and motivated behaviors.

neural system located below the cerebral hemispheres (structures include the amygdala, hypothalamus, & hippocampus); associated w/ emotions & drives. (p. 104)

thalamus

brain’s sensory control center (“sensory switchboard”), located on top of the brainstem; directs messages to the sensory receiving areas in the cortex & transmits replies to the cerebellum & medulla. (p. 102)

electroenchephalogram (EEG)

device that monitors and records waves of electrical activity sweeping across the brain’s surface; measured by electrodes placed on the scalp. (p. 99)

positron emission tomography (PET scan)

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task. (p. 99)

computed tomography (CT) scan

imaging technique that involves the production of a large number of X-ray photographs taken from different angles & combined by a computer into a composite representation of a slice of the brain’s structure. (also called CAT scan). (p. 99)

magnetic resonance imaging (MRI)

an imaging technique that involves the use of magnetic fields & radio waves to produce computer-generated images of soft tissue; shows brain anatomy (p. 99)

dendrites

short, bushy, branchlike structures of a neuron that receive & integrate information from receptors and other neurons by conducting impulses toward the cell body. (p. 82)

functional MRI (fMRI)

technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans; capable of showing BOTH structure and function of the brain. (p. 100)

soma (cell body)

cell body of a neuron; contains the nucleus; the cell’s life support center. (p. 82)

axon

part of a neuron (neuron extension) that transmits information to other neurons and to muscles and glands through its branches. (p. 82)

myelin sheath

fatty tissue layer (protein substance) that encases some axons, increasing the speed of transmission as neural impulses hop from one node to the next. (p. 82)

neurotransmitters

chemical messengers that cross the synaptic gap between neurons. when released by the sending neuron, neurotransmitters travel across the synapse & bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse. (p. 85)

synapse

site between the sending neuron’s axon tip & the dendrite/cell body of the receiving neuron; interact but don’t touch. tiny gap at this junction is called the synaptic gap/cleft. (p. 85)

reuptake

method of clearing a neurotransmitter from the synaptic cleft, in which the neurotransmitter is reabsorbed into the terminal buttons.

neurotransmitter’s reabsorption by the sending neuron. (p. 86)

synaptic vesicles

small pockets or sacs located in terminal buttons that contain a neurotransmitter

agonist

a molecule (e.g., drug) that enhances the operation of a neurotransmitter. (p. 88)

antagonist

a molecule (e.g., drug) that blocks or inhibits the operation of a neurotransmitter (p. 89)

endorphins

"morphine within"; natural, opiate-like neurotransmitters linked to pain control and to pleasure. (p. 88)

resting potential

electrical charge (negative) of a neuron when it is not firing

action potential

a neural impulse; brief electrical charge that travels down the axon; a process also called "depolarization". (p. 83)

threshold

the level of stimulation required to trigger a neural impulse. (p. 83)

refractory period

(1) in neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials (polarizing, repolarizing(?)) can’t occur until the axon returns to its resting state.

(2) in human sexuality, a resting period that occurs after orgasm, during which a person can’t achieve another orgasm. (pp. 83, 552)

aphasia

loss of ability to speak or understand written or spoken language

endocrine system

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream. (p. 95)

hormones

chemicals produced by the glands of the endocrine system that are carried by the bloodstream to other body tissues. (p. 95)

pituitary gland

gland located below the thalamus and hypothalamus; called the "master gland" of the endocrine system because it controls many other glands

biological psychology

branch of psychology concerned with the links between biology (genetic, neural, and hormonal) and behavior (psychological processes). (p. 17)

acetylcholine (ACh)

a neurotransmitter that enables muscle action, learning and memory; an undersupply is linked with Alzheimer's disease

dopamine

a neurotransmitter that influences movement, learning and attention; overactivity of receptors linked to schizophrenia while an undersupply linked to Parkinson's disease

serotonin

a neurotransmitter that affects mood, hunger, sleep, and arousal. An undersupply of this neurotransmitter is linked with depression.

norepinephrine

a neurotransmitter that controls alertness and arousal; undersupply can depress mood

GABA

a major inhibitory neurotransmitter; undersupply linked to seizures, tremors, and insomnia

glutamate

a major excitatory neurotransmitter; oversupply can overstimulate brain, producing migraines or seizures

nerves

bundled axons that form neural "cables" connecting the CNS to the rest of the body. (p. 92)

interneurons

central nervous system neurons that internally communicate and intervene between sensory inputs and motor outputs. (p. 93)

• basically, they process the input of the sensory neurons and decide what the output (response) should be.

lesion

tissue destruction (usually brain tissue); can be naturally caused or created for experimentation.

hippocampus

a neural center located in the limbic system; helps process for storage of explicit (conscious) memories of facts & events. (pp. 106, 340)

hypothalamus

neural structure lying below (hypo) the thalamus; directs several maintenance activities (eating, drinking, body temp); helps govern the endocrine system via the pituitary gland & is linked to emotion & reward. (p. 104)

Paul Broca

responsible for discovering the area on the left frontal lobe responsible for coordinating muscle movements involved in spoken language

Carl Wernicke

discovered a brain area responsible for interpreting meaning of language

depolarization

process of neural firing; when action potential is generated and the neuron briefly takes on a positive charge

all-or-none response

neuron will only fire (if threshold is reached) and w/ a full-strength response OR not fire (if stimulation is insufficient). (p. 83)

amygdala

the two lima-bean-sized (or almond-shaped) neural clusters in the limbic system; linked to emotion. (p. 104)

• believed to be responsible for fear and aggressive responses

cerebral cortex

wrinkled, gray, intricate fabric of interconnected neural cells covering both the cerebral hemispheres; accounts for 80% of brain weight; the body’s ultimate control & info-processing center (complex processing of information, planning, learning, memory storage, etc.). (p. 109)

Phineas Gage

famous case study in neuroscience; sustained catastrophic damage to his frontal lobes

motor cortex

located on the rear of the frontal lobes; responsible for directing voluntary movement on the opposite side of the body. (p. 110)

somatosensory cortex

located on the front of the parietal lobes; registers and processes body touch and movement sensations. (p. 113)

occipital lobes

a portion of the cerebral cortex at the "back" of the head; includes areas that receive info from the visual fields, and also contains the visual cortex. (p. 110)

temporal lobes

portion of the cerebral cortex located on the "sides" of the brain lying roughly above the ears; includes auditory areas, each receiving information primarily from the opposite ear. (p. 110)

Roger Sperry & Michael Gazzaniga

studied split brain patients.

phrenology

early, misguided attempt at studying the functions of parts of the brain; held that bumps on the skull revealed the person's personality traits

Franz Gall

early comparative brain anatomist; developed phrenology

Broca's area

area (usually in the left frontal lobe) that directs the muscle movements involved in speech

Wernicke's area

brain area involved in language comprehension; usually in left temporal lobe

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. (p. 144)

angular gyrus

transforms visual representations into an auditory code; damage to this leaves the person unable to speak and understand, but able to read

neuroplasticity

brain's ability to reorganize and change its structure and function throughout the life span, in response to injury or new learning.

hemispheric specialization

This is also called lateralization; refers to the fact that the left and right hemispheres of the brain have some specific functions that exist only in those hemispheres.

contralateral control

The left hemisphere controls the right side of the body and the right hemisphere controls the left side.

nervous system (NS)

the body's speedy, electrochemical communication network, consisting of all the nerve cells of the central and peripheral nervous systems. (p. 91)

adrenal glands

A pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress.

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. (p. 109)

glial cells (glia)

cells in the nervous system that support, nourish, and protect neurons; also play a role in learning, thinking, & memory. (p. 82)

frontal lobes

the portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments. (p. 109)

neurogenesis

the formation of new neurons. (p. 117)

split brain

• a condition resulting from surgery that isolates the brain’s two hemispheres by cutting the connecting fibers (mainly those of the corpus callosum) between them. (p. 120)

• often a treatment for severe epilepsy.

multiple sclerosis

a progressive disease of the nervous system that involves a degeneration of the myelin that surrounds nerve fibers in the brain and spinal cord.

adoption studies

Assess hereditary influence by examining the resemblance between adopted children and both their biological and their adoptive parents.

behavior genetics

the study of the relative power and limits of genetic and environmental influences on behavior. (pp. 14, 129)

charles darwin

english natural scientist who formulated a theory of evolution by natural selection. (p. 14)

concordance rates

The percentage of cases where both twins share the same trait or disorder

Dmitry Belyaev

Russian geneticist who, through artificial selection, bred tame foxes

epigenetics

study of how the environment can alter gene expression or function (e.g. light, nutrition, temperature, presence of other species); example of interaction of nature & nurture. (pp. 137, 668)

evolutionary psychology

the study of the evolution of behavior and the mind, using principles of natural selection. (pp. 14, 141)

fraternal (dizygotic) twins

twins who develop from separate eggs; genetically no closer than brothers and sisters (regular siblings), but they share a prenatal/fetal environment. (p. 132)

genes

biochemical units of heredity that make up the chromosomes; a segment of DNA capable of synthesizing a protein. (p. 130)

genome

all the genetic information in an organism; all of an organism's chromosomes. (p. 130)

• the instructions needed for making an organism.

identical (monozygotic) twins

twins who develop from a single fertilized egg that splits in two, resulting in two individuals that share the exact same DNA. (p. 131)

mutation

a random error in gene replication that leads to a change in nucleotide sequence. (p. 142)

natural selection

a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits. (pp. 14, 141)

Thomas Bouchard

U of M researcher who studied identical twins separated at birth

epinephrine

A hormone produced by the adrenal glands that has a vital role in the function of the sympathetic nervous system (and its "fight or flight" response). Also sometimes referred to as a neurotransmitter.

prefrontal cortex

the front-most portion of the frontal lobes; involved in planning and reasoning; one of the last areas of the brain to mature (and sometimes used to explain adolescents' relative lack of impulse control).

reflex arc

the nerve pathway involved in a reflex action including at its simplest a sensory nerve and a motor nerve with a synapse between.

myasthenia gravis

a chronic autoimmune disease that affects the neuromuscular junction and produces serious weakness of voluntary muscles