psychology

the scientific study of behavior and mental processes

empiricism

the view that (a) knowledge comes from experience via the senses, and (b) science flourishes through observation and experiment

structuralism

an early school of psychology that used introspection to explore the elemental structure of the human mind

functionalism

a school of psychology that focused on how mental and behavioral processes function -- how they enable the organism to adapt, survive, and flourish

humanistic psychology

historically significant perspective that emphasized the growth poetntial of healthy people; used personalized methods to study personality in hopes of fostering personal growth

nature-nurture issue

the longstanding controversy over the relative contributions that genes and experience make to the development of psychological traits and behaviors

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

biopsychosocial approach

this integrated viewpoint incorporates various levels of analysis and offers a more complete picture of any given behavior or mental process

basic research

pure science that aims to increase the scientific knowledge base

applied research

scientific study that aims to solve practical problems

counseling psychology

a branch of psychology that assists people with problems in living (often related to school, work, or marriage) and in achieving greater well-being

clinical psychology

a branch of psychology that studies, assesses, and treats people with psychological disorders

psychiatry

a branch of medicine dealing with psychological disorders; practiced by physicians who sometimes provide medical treatments as well as psychological therapy

hindsight bias

the tendency to believe, after learning an outcome, that one would have foreseen it (aka the "I knew it all along" phenomenon)

critical thinking

thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions

theory

an explanation using an integrated set of principles that organizes and predicts observations

hypothesis

a testable prediction, often implied by a theory

operational definition

a statement of the procedures (operations) used to define research variables (ex. "human intelligence" may be operationally defined as what an intelligence test measures)

replication

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances

culture

the enduring behaviors, ideas, attitudes, and traditions shared by a large group of people and transmitted from one generation to the next

case study

an observation technique in which one person is studied in depth in the hope of revealing universal principles

survey

a technique for ascertaining the self-reported attitudes or behaviors of people, usually be questioning a representative, random sample of them

false consensus effect

the tendency to overestimate the extent to which others share our beliefs and behaviors

population

all cases in a group, from which samples may be drawn for a study (note: except for national studies, this does *not* refer to a country's whole population)

random sample

a sample that fairly represents a population because each number has an equal chance of inclusion

naturalistic observation

observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation

correlation

a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other. The correlation coefficient is the mathematical expression of the relationship, ranging from -1 to +1

scatterplot

a graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. the amount of scatter suggests the strength of the correlation (little scatter indicates high correlation); aka scattergram or scatter diagram

illusionary correlation

the perception of a relationship where none exists

experiment

a research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable). By random assignment of participants, the experimenter aims to control other relevant factors

double-blind procedure

an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo; commonly used in drug evaluation studies

placebo effect

Latin for "I shall please;" experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which is assumed to be an active agent

experimental condition

the condition of an experiment that exposes participants to the treatment; that is, to one version of the independent variable

control condition

the condition of an experiment that contrasts with the experimental condition and serves as a comparison for evaluating the effect of the treatment

random assignment

assigning participants to experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups

independent variable

the experimental factor that is manipulated; the variable whose effect is being studied

dependent variable

the outcome factor; the variable that may change in response to manipulations of the independent variable

mode

the most frequently occurring score(s) in a distribution

mean

the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores

median

the middle score in a distribution; half the scores are above it and half are below it

range

the difference between the highest and lowest scores in a distribution

standard deviation

a computed measure of how much scores vary around the mean score

statistical significance

a statistical statement of how likely it is that an obtained result occurred by chance

biological psychologists

psychologists concerned with the links between biology and behavior (behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists 

dendrite

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward a cell body

axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

myelin sheath

a layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next

action potential

a neural impulse; a brief electrical charge that travels down an axon; the action potential is generated by the movement of positively charged atoms in and out of channels in the axon's membrane

synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron; the tiny gap at this junction is called the *synaptic gap* or *cleft*

neurotransmitters

chemical messengers that traverse 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 or not that neuron will generate a neural impulse

acetylcholine

a neurotransmitter that enables learning and memory and also triggers muscle contraction

endorphins

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

reflex

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

neural networks

interconnected neural cells; with experience, networks can learn, as feedback strengthens or inhibits connections that produce certain results; computer simulations of neural networks show analogous learning

electroencephalogram

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

PET (proton emission tomography)

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

MRI (magnetic resonance imaging)

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 (functional magnetic resonance imaging)

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

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

reticular formation

a nerve network in the brainstem that plays an important role in controlling arousal

thalamus

the brain's sensory switchboard, 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

cerebellum

the "little brain" attached to the rear of the brainstem; its functions include processing sensory input and coordinating movement output and balance

limbic system

a doughnut-shaped system of neural structures at the border of the brainstem and cerebral hemispheres; associated with emotions such as fear and aggression and drives such as those for food and sex; includes the hippocampus, amygdala, and hypothalamus

amygdala

two lima bean-sized neural clusters that are components of the limbic system and are linked to emotion