AP Psychology: Terms

Psychology

Scientific study of behavior and mental processes

Behaviorism

(John Watson) A theoretical orientation based on the premise that scientific psychology should study only observable behavior; emphasizes learning mechanisms

Functionalism

A school of psychology, founded by William James, that focused on how our mental and behavioral processes function - how they enable us to adapt, survive, and flourish.

Structuralism

(Titchener) An early school of psychology that used introspection to explore the elemental structure of the human mind.

Evolutionary psychology

A relatively new specialty in psychology that sees behavior and mental processes in terms of their genetic adaptations for survival and reproduction.

Gestalt psychology

A psychological approach that emphasizes that we often perceive the whole rather than the sum of the parts.

Cognitive psychology

An approach to psychology that emphasizes internal mental processes; thinking, knowing, remembering, and communicating

Introspection

A method of self-observation in which participants report their thoughts and feelings

Population

Pool of people from which research sample is drawn and that the sample is intended to represent.

Scientific method

A series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis, and stating conclusions.

Dependent variable

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

Independent variable

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

Case study

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

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.

Control group

In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

Hypothesis

A testable prediction, often implied by a theory

Naturalistic observation

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

Survey

A study, generally in the form of an interview or questionnaire, that provides researchers with information about how people think and act.

Theory

A well-substantiated explanation of some aspect of the natural world; organizes known information about a topic and leads to the development of testable hypotheses

Correlation coefficient

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

Operational definition

A statement that describes how to measure a particular variable.

Experimental group

A subject or group of subjects in an experiment that is exposed to the factor or condition being tested.

Correlational research

A research strategy that identifies the relationships between two or more variables in order to describe how these variables change together. One advantage is that it helps psychologists make predictions.

Random assignment

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

Mean

A measure of central tendency also known as the mathematical average; found by adding values together and dividing by the total number of items

Normal distribution

A bell-shaped curve, describing the spread of a characteristic throughout a population.

Double blind study

A procedure in which neither the researcher nor the participant knows which group is the experimental group. Reduces both participant and experimenter bias.

Median

A measure of central tendency; the middle number in a set of numbers that are listed in order

Mode

A measure of central tendency that uses most frequently occurring score.

Sample

A relatively small proportion of people who are chosen in a survey so as to be representative of the whole.

Standard deviation

A measure of variability that describes an average distance of every score from the mean

Inferential statistics

numerical methods used to determine whether research data support a hypothesis or whether results were due to chance

Placebo effect

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.

Placebo

A chemically inert substance that produces real medical benefits because the patient believes it will help.

Range

Distance between highest and lowest scores in a set of data.

Descriptive statistics

Exploratory methods used to describe and summarize the characteristics of samples or populations. Includes measures of central tendency and measures of variation.

Informed consent

An ethical principle requiring that research participants be told enough to enable them to choose whether they wish to participate.

Replication

the repetition of an experiment in order to test the validity of its conclusion

Variables

Any measurable conditions, events, characteristics, or behaviors that are controlled or observed in a study.

Axon

A long projection off the cell body of a neuron down which an action potential can be propagated.

Central Nervous System (CNS)

Brain and spinal cord

Cerebral cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center.

Dendrites

A neuron's bushy, branching extensions that receive messages and conduct impulses toward the cell body.

Peripheral Nervous System

All of the neurons that are not in the central nervous system. Carries information to and from the central nervous system.

Synapse

A junction where information is transmitted from one neuron to the next.

Thalamus

Brain structure that receives messages from the sense organs and relays the information to the proper region of the cerebrum for further processing

Autonomic nervous system

A subdivision of the peripheral nervous system. Controls involuntary activity of visceral muscles and internal organs and glands.

Gene

A segment of DNA on a chromosome that codes for a specific trait

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.

Neurons

A nerve cell; the basic building block of the nervous system.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, they travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.

Sympathetic nervous system

A subdivision of the autonomic nervous system that activates nerves, glands and visceral muscles in times of stress or threat (prepares the body for action)

Action potential

A neural impulse; a brief electrical charge that travels down an axon.

Cerebellum

Control of finely coordinated movements. Coordination center, voluntary movement and balance. "Little brain."

Hormone

Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another.

Limbic system

A group of subcortical structures (such as the hypothalamus, the hippocampus, and the amygdala) of the brain that are concerned especially with emotion and motivation.

Parasympathetic nervous system

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

Homeostasis

A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level

Chromosomes

A threadlike, gene-carrying structure found in the nucleus. Each consists of one very long DNA molecule and associated proteins.

Corpus callosum

A thick band of axons that connects the two cerebral hemispheres and acts as a communication link between them.

Myelin sheath

A white, fatty covering wrapped around the axons of some neurons that increases their communication speed.

Pituitary gland

Brain part which secretes factors into the blood which act on the endocrine glands to either increase or decrease hormone production

Endocrine system

Glands that secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells.

Somatic nervous system

A subdivision of the peripheral nervous system. Enables voluntary actions to be undertaken due to its control of skeletal muscles

Medulla

Base of brainstem; controls heartbeat and breathing

Sensory neuron

Neurons that carry incoming information from the sensory receptors to the brain and spinal cord. (Afferent)

Cell body

Processes nutrients and provides energy for the neuron to function; contains the cell's nucleus; also called the soma.

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

Glial cells

Cells in the nervous system that support, nourish, and protect neurons

Positron emission tomography (PET)

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

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.

Endorphins

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

Magnetic resonance imaging (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.

Occipital lobes

the portion of the cerebral cortex lying at the back of the head; includes the visual areas, which receive visual information from the opposite visual field

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.

Temporal lobes

Portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear.

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.

Amygdala

A limbic system structure involved in memory and emotion, particularly fear and aggression.

Hippocampus

A neural center located in the limbic system that helps process explicit memories for storage.

Interneurons

Central nervous system neurons that internally communicate and intervene between the sensory inputs and motor outputs

Reticular formation

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

Behavioral genetics

An interdisciplinary field that studies the influence of genetic factors on behavioral traits.

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.

Pons

A brain structure that relays information from the cerebellum to the rest of the brain

Resting potential

State in which a neuron is not transmitting a nerve impulse. A neuron in this state has a net negative charge relative to its outside environment, and this state of potential energy prepares it to be activated by an impulse from an adjacent neuron.

Basilar membrane

A structure that runs the length of the cochlea in the inner ear and holds the auditory receptors, called hair cells.

Midbrain

Collection of brain structures in middle of brain responsible for coordinating movement patterns, sleep, & arousal

Motor neurons

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

Receptors

In neurons, specialized protein molecules on the postsynaptic membrane; neurotransmitters bind to these molecules after passing across the synaptic cleft.

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

Eardrum

tightly stretched membrane located at the end of the ear canal that vibrates when struck by sound waves

Identical twins

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

All or none principle

the law that the neuron either generates an action potential when the stimulation reaches threshold or it doesn't fire when stimulation is below threshold

CT (computed tomography) scan

is a series of X-ray photographs combined by computer into a composite representation of a slice through the brain

DNA

A complex molecule containing the genetic information that makes up the chromosomes

Fraternal twins

Twins who develop from separate eggs. They are genetically no closer than brothers and sisters, but they share a fetal environment.

Functional magnetic resonance imaging (fMRI)

A noninvasive imaging technique that uses magnetic fields to map brain activity by measuring changes in the brain's blood flow and oxygen levels

Genotype

Genetic makeup of an organism

Hindbrain

Area containing the medulla, pons, and cerebellum.

Phenotype

An organism's physical appearance, or visible traits.