AP Psych FRQ Terms

• operational definition


  a carefully worded statement of the exact procedures (operations) used in a research study. (necessary for replication)
• 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).
• correlation


  a measure of the extent to which two variables change together, and thus of how well either variable predicts the other.
• dependent variable


  the outcome factor; the variable that may change in response to manipulations (variable that is manipulated)
• statistical significance

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


  assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between the different groups.
• double-blind experiment


  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.
• independent variable


  the experimental factor that is manipulated; the variable whose effect is being studied.
• informed consent


  an ethical principle that research participants be told enough 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.
• hypothesis


  a testable prediction, often implied by a theory.
• illusory correlation


  the perception of a relationship where none exists.
• 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.
• descriptive statistics


  numerical data used to measure and describe characteristics of groups. Includes measures of central tendency and measures of variation.
• single-blind study

  study in which the subjects do not know if they are in the experimental or the control group
• random selection


  A way of ensuring that a sample of people is representative of a population by giving everyone in the population an equal chance of being selected for the sample
• survey


  a technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group.
• case study


  a descriptive technique in which one individual or group is studied in depth in the hope of revealing universal principles.
• naturalistic observation


  observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation.
• prefrontal cortex


  part of frontal lobe responsible for thinking, planning, and language (Broca's area is in it's left lobe)
• sympathetic nervous system


  the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.
• 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.
• dopamine


  A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system.
• somatosensory cortex (sensory cortex)


  area at the front of the parietal lobes that registers and processes body touch and movement sensations.
• motor neuron


  a neuron that sends an impulse to a muscle or gland, causing the muscle or gland to react. (part of the peripheral nervous system)
• serotonin


  A neurotransmitter that affects hunger,sleep, arousal, and mood.
• motor cortex


  an area at the rear of the frontal lobes that controls voluntary movements.
• Broca's area


  Controls language expression - an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech.
• 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.
• occipital lobe


  portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields.
• evolutional psychology


  the study of the evolution of behavior and the mind, using principles of natural selection
• cerebellum


  the "little brain" at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory.
• Acetylcholine (ACh)


  A neurotransmitter that enables learning and memory and also triggers muscle contraction
• long-term potentiation


  an increase in a synapse's firing potential after brief, rapid stimulation. Believed to be a neural basis for learning and memory.
• circadian rhythm


  the biological clock; regular bodily rhythms that occur on a 24-hour cycle
• REM sleep


  Rapid eye movement sleep, a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active.
• retinal disparity


  a binocular cue for perceiving depth by comparing images from the retinas in the two eyes, the brain computes distance—the greater the disparity (difference) between the two images, the closer the object.
• difference threshold


  the minimum difference between two stimuli required for detection 50 percent of the time.
• selective attention


  the focusing of conscious awareness on a particular stimulus.