all psychology terms

psychology

the science of behavior and mental processes

nature-nurture issue

the long-standing 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

neuroscience

the perspective of psychological science that deals with how the body and brain create emotions, memories, and sensory experiences

evolutionary

the perspective of psychological science that deals with how nature selects traits that promote the perpetuation of one's genes

behavior genetics

the perspective of psychological science that deals with how much our genes, and our environment, influence our individual differences

psychodynamic

the perspective of psychological science that deals with how behavior springs from unconscious drives and conflicts

behavioral

the perspective of psychological science that deals with how we learn observable responses

cognitive

the perspective of psychological science that deals with how we encode, process, store, and retrieve information

social-cultural

the perspective of psychological science that deals with how behavior and thinking vary across situations and cultures

basic research

pure science that aims to increase the scientific knowledge base

applied research

scientific study that aims to solve practical problems

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 (for example, drug) treatments as well as psychological therapy

hindsight bias (I-knew-it-all-along phenomenon)

the tendency to believe, after learning an outcome, that one would have foreseen it

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. For example, 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 generalizes to other participants and circumstances

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 by 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 the cases in a group, from which samples may be drawn for a study

random sample

a sample that fairly represents a population because each member 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 coefficient

a statistical measure of the extent to which two factors vary together, and thus of how well either factor predicts the other

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 correlation (little scatter indicates high correlation).

illusory 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 controls other relevant factors)

placebo

an inert substance or condition that may be administered instead of a presumed active agent, such as a drug, to see if it triggers the effects believed to characterize the active agent

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

any effect on behavior caused by a placebo

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 evaluation 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 if being studied

dependent variable

the experimental factor--in psychology, the behavior or mental process--that is being measured

the variable that may change in response to the manipulations of the independent variable

mode

the most frequently occurring score 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

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 criterion for rejecting the assumption of no differences in a particular study

culture

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

Biological psychology

concerned with links between biology and behavior

Neuron

building blocks of the nervous system

Dendrite

Branches designed to receive/send/and transport information

Axon

transports messages to different muscles/glands in the body

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.

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

Threshold

the level of stimulation required to trigger a neural impulse

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 it will generate a neural impulse

Acetylcholine

a neurotransmitter that, among its functions, triggers muscle contraction

Endorphins

"morphine within" - natural, opiatelike neurotransmitters linked to pain control and to pleasure.

Nervous system

the body's speedy, electrochemical communication system, consisting of all the nerve cells of the peripheral and central nervous systems.

Central nervous system (CNS)

the brain and spinal cord

Peripheral nervous system (PNS)

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

Nerves

Neural "cables" containing many axons. These bundled axons, which are part of the peripheral nervous system, connect the central nervous system with muscles, glands, and sense organs

Sensory neurons

neurons that carry incoming information from the sense receptors to the central nervous system

Interneurons

central nervous system neurons that intervene between the sensory inputs and motor outputs

Motor neurons

The neurons that carry outgoing information from the central nervous system to the muscles and glands

Somatic nervous system

the division of the peripheral nervous sytem 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

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 stimulations of neural networks show analogous learning.

Phrenology

an ill-fated theory that claimed bumps on the skull could reveal our mental abilities and our character traits.

lesion

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

EEG (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

CT (computed tomography)

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 (positron 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

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

it helps coordinate voluntary movement 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 almond-shaped neural clusters that are components of the limbic system and are 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

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 are not neurons but that support, nourish, and protect neurons

frontal lobes

the portion of the cerebral cortex lying just behind the forehead