psych unit 3 vocab

phrenology - the detailed study of the shape and size of the cranium as a supposed indication of character and mental abilities

biological psychology - the scientific study of the links between biological and psychological processes

neuron - a nerve cell; the basic building block of the nervous system

dendrite - a neuron's bushy, branching extensions that receive messages and conduct impulses toward the cell body

axon - the neuron extension that passes messages through its branches to other neurons or to muscles or glands

soma - cell body

myelin sheath - a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next

action potential - a neural impulse; a brief electrical charge that travels down an axon

depolarization - happens during action potential: sodium (& +) ions rush in, causing potassium (& -) ions to rush out

repolarization - process by which negative resting potential is restored

refractory 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

resting potential - the state of the neuron when not firing a neural impulse, positive-outside/negative-inside state

synapse - the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

neurotransmitter - chemical messengers that cross the synaptic gaps 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

reuptake - a neurotransmitter's reabsorption by the sending neuron

excitatory vs inhibitory - neurons differ in their "readiness" to fire. excitatory=lower threshold, more ready to fire; inhibitory=higher threshold, more hesitant to fire

acetycholine (ACh) - enables muscle action, learning, and memory

dopamine - influences movement, learning, attention, and emotion. pleasure

norepinephrine (NE) - helps control alertness and arousal

seratonin - affects mood, hunger, sleep, and arousal

GABA (gamma-aminobutyric acid) - a major inhibitory neurotransmitter

endorphins - "morphine within"—natural, opiate-like neurotransmitters linked to pain control and to pleasure

agonist - a molecule that, by binding to a receptor site, stimulates a response

antagonist - a molecule that, by binding to a receptor site, inhibits or blocks a response

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 - brain and spinal cord

peripheral nervous system - the sensory and motor neurons that connect the central nervous system 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 - 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

autonomic nervous system - the part of the peripheral nervous system that controls the glands and the 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

parasympathetic nervous system - the division of the autonomic nervous system that calms the body, conserving its energy

neural networks - networks of nerve cells that integrate sensory input and motor output

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 glands, travel through the bloodstream, and affect other tissues

adrenal glands - a pair of endocrine glands that sit just above the kidneys and secrete hormones (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 controls other endocrine glands.

feedback system - brain -> pituitary -> other glands -> hormones -> body and brain

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

electroencephalogram (EEG) - an amplified recording of the waves of electrical activity that sweep 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 through the body

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 that distinguish among different types of soft tissue; allows us to see structures within the brain

fMRI - a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans.

brainstem - 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 - a nerve network in the brainstem that travels through the brainstem & thalamus and plays an important role in controlling arousal

pons - a brain structure that relays information from the cerebellum to the rest of the brain. sleep and arousal

cerebellum - the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance

limbic system - neural system located below the cerebral hemispheres; associated with emotions and drives

hippocampus - a neural center located in the limbic system; helps process explicit memories for storage

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

hypothalamus - a neural structure lying below 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.

James Olds and Peter Milner - discovered "pleasure-centers" in the limbic system

cerebral cortex - the intricate fabric of interconnected neural cells that covers the cerebral hemispheres; the body's ultimate control and information-processing center

glial cells - cells in the nervous system that support, nourish, and protect neurons

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

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; includes areas that receive information from the visual fields

temporal lobes - portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily 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

visual cortex - the visual processing areas of cortex in the occipital lobe

auditory cortex - the area of the temporal lobe responsible for processing sound information

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 - the formation of new neurons

Phineas Gage - railroad worker who survived a severe brain injury that dramatically changed his personality and behavior; case played a role in the development of the understanding of the localization of brain function

Paul Broca -> Broca's area - discovered area in the brain (named for him) in the left frontal lobe responsible for language production

Carl Wernicke -> Wernicke's Area - an area of the brain (in the left temporal lobe) involved in language comprehension and expression was named for him because he discovered it

aphasia - impairment of language, usually caused by left hemisphere damage either to Broca's area (impairing speaking) or to Wernicke's area (impairing understanding).

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

brain lateralization - specialization of function in each hemisphere

brain localization - the idea that certain parts of the brain control specific mental abilities and personality characteristics

consciousness - our awareness of ourselves and our environment

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

Michael Gazzaniga & Roger Sperry - psychologists; split brains in mice/rats/cats and showed that they weren't affected; later conducted split brain research on humans

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

enviorment - every external influence, from prenatal nutrition to the people and things around us

chromosomes - threadlike structures made of DNA molecules that contain the genes

dna - a complex molecule containing the genetic information that makes up the chromosomes

genes - the biochemical units of heredity that make up the chromosomes; a segment of DNA capable of synthesizing a protein

genome - the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes

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

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

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

gene interaction - interaction between genes at different loci that affect the same characteristic

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