AP Psych vocab (1)

Scientific method

A self-correcting process for asking questions and observing natural answers.

Hypothesis

A theory that can be tested.

Theory

Explains behaviors or events by offering ideas that organize observations.

Operational definitions

A carefully worded statement of the exact procedures used in a research study.

Replication

Repeating the essence of a research study, usually with different participants in different situations to see whether the basic finding can be reproduced.

Naturalistic observation

A descriptive technique of observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation.

Case study

A descriptive technique in which one individual or group is studied in depth in the hope of revealing universal principles.

Survey

A descriptive technique for obtaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group.

Sampling bias

Flawed sampling process that produces an unrepresentative sample.

Population

All those in a group being studied, from which samples may be drawn.

Random sample

A sample that fairly represents a population because each member has an equal chance of inclusion.

Correlation

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

Correlation coefficient

A statistical index of the relationship between two things (from -1.00 to 1.00).

Variable

Anything that can vary and is feasible and ethical to measure.

Scatterplot

A graphed cluster of dots, each of which represents the values of two variables.

Illusory correlation

Perceiving a relationship where none exists, or perceiving a stronger than actual relationship.

Regression toward the mean

The tendency for extreme or unusual scores or events to fall back (regress) toward the average.

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 (dependent variable).

Experimental group

In an experiment, the group exposed to the treatment, that is, to one version of the independent variable.

Control group

In an experiment, the group not exposed to the treatment; contrasts with the experimental group.

Random assignment

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

Double-blind procedure

An experimental procedure in which both the research participants and the research staff are ignorant about whether the research participants have received the treatment or a placebo.

Placebo

Experimental results caused by expectations alone.

Independent variable

In an experiment, the factor that is manipulated, the variable whose effect is being studied.

Inferential statistics

Numerical data that allow one to generalize - to infer from sample data the probability of something being true of a population.

Statistical significance

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

Confounding variable

A factor other than the factor being studied that might influence a study’s results.

Dependent variable

In an experiment, the outcome that is measured; the variable that may change when the independent variable is manipulated.

Validity

The extent to which a test or experiment measures or predicts what it is supposed to.

Informed consent

Giving potential participants enough information about a study to enable them to choose whether they wish to participate.

Debriefing

The postexperimental explanation of a study, including its purpose and any deceptions, to its participants.

Descriptive statistics

Numerical data used to measure and describe characteristics of groups.

Histogram

A bar graph depicting a frequency distribution.

Mode

The most frequently occurring score(s) in a distribution.

Mean

The arithmetic average of a distribution.

Median

The middle score in a distribution.

Skewed distribution

A representation of scores that lack symmetry around their average value.

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.

Normal curve

A symmetrical, bell-shaped curve that describes the distribution of many types.

Neuron

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

Cell body

The part of a neuron that contains the nucleus, the life support center.

Dendrites

Branching extensions of a neuron that receive and integrate messages.

Axon

The neuron extension that passes messages through its branches to other neurons.

Myelin sheath

A fatty tissue layer segmentally encasing the axons of some neurons.

Glial cells

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

Action potential

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

Threshold

The level of stimulation required to trigger a neural impulse.

Refractory period

A brief resting pause that occurs after a neuron has fired.

All-or-none response

A neuron’s reaction of either firing or not firing.

Synapse

The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons.

Reuptake

A neurotransmitter's reabsorption by the sending neuron.

Endorphins

Natural, opiate-like neurotransmitters linked to pain and to pleasure.

Agonist

A molecule that increases a neurotransmitter action.

Antagonist

A molecule that inhibits or blocks a neurotransmitter action.

Nervous system

The body’s speedy, electrochemical communication network.

Central nervous system

The brain and spinal cord.

Peripheral nervous system

The sensory and motor neurons that connect the CNS to the rest of the body.

Nerves

Bundled axons that form neural cables connecting the CNS with muscles, glands, and sense organs.

Sensory neurons

Neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord.

Motor 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 process information.

Somatic nervous system

The division of the peripheral nervous system that controls the body’s skeletal muscles.

Autonomic nervous system (ANS)

Controls the glands and the muscles of the internal organs.

Sympathetic nervous system

The division of the ANS that arouses the body.

Parasympathetic nervous system

The division of the ANS that calms the body.

Reflex

A simple automatic response to a sensory stimulus.

Endocrine system

The body’s slow chemical communication system.

Hormones

Chemical messengers manufactured by the endocrine glands.

Adrenal glands

Endocrine glands that sit above the kidneys and secrete hormones that help arouse the body.

Pituitary gland

The endocrine system’s most influential gland.

Lesion

Tissue destruction.

EEG (electroencephalogram)

An amplified recording of the waves of electricity sweeps across the brain.

MEG (magnetoencephalography)

A brain imaging technique that measures magnetic fields from the brain’s natural electrical activity.

CT scan (computed tomography)

A series of x-ray photographs taken from different angles and combined into a composite representation.

PET (position emission tomography) scan

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

MRI (magnetic resonance imaging)

A technique that uses magnetic fields and radio waves to produce images of soft tissue.

fMRI (functional MRI)

A technique for revealing blood flow and brain activity.

Brain stem

The oldest part and central core of the brain that is responsible for automatic survival functions.

Medulla

The base of the brain stem controlling heartbeat and breathing.

Thalamus

The brain’s sensory control center.

Reticular formation

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

Cerebellum

The little brain at the rear of the brainstem.

Limbic system

A neural system located below the cerebral hemispheres, associated with emotions and drives.

Amygdala

Two lima bean neural clusters in the limbic system linked to emotion.

Hypothalamus

A neural structure lying below the thalamus that directs several maintenance activities.

Hippocampus

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

Cerebral cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres.

Frontal lobes

The portion of the cerebral cortex involved in speaking, muscle movements, and making plans and judgments.

Parietal lobes

The portion of the cerebral cortex that receives sensory input for touch and position.

Occipital lobes

The portion of the cerebral cortex that includes areas receiving information from the visual fields.

Temporal lobes

The portion of the cerebral cortex that includes auditory areas.

Motor cortex

An area controlling voluntary movements; located at the rear of the frontal lobes.

Somatosensory cortex

An area that registers and processes body touch and movement sensations.

Association areas

Areas of the cerebral cortex not involved in primary motor or sensory functions.

Plasticity

The brain's ability to change, especially during childhood.

Neurogenesis

The formation of new neurons.

Corpus Callosum

The large band of neural fibers connecting the two brain hemispheres.

Split brain

A condition resulting from surgery that isolates the brain's two hemispheres.