AP Psych All Terms

Independent variable (IV)

the thing that is being manipulated in an experiment

Dependent variable (DV)

the variable that changes in response to the change in the independent variable

Confounding variables

a variable other than the independent variable that might produce an effect in an experiment

Random assignment

randomly assigning participants to experimental groups to avoid bias

Population

a group of people that a researcher aims to study

Random sampling

choosing participants for a study/experiment in a completely random way (every member of the population has an equal chance of being selected)

Representative samples

a smaller group selected from a larger population that accurately mirrors the key characteristics of the entire population

Convenience samples

sampling technique where participants are selected based on convenience, causing a sample to not be representative

Sampling bias

sampling error that occurs when some members of the population are systematically more likely to be selected, resulting in a sample that is not representative

Generalizability

the degree to which experimental findings can be applied to a larger/broader population

Experimental group

group(s) in an experiment that receive experimental treatment

Control group

a group in an experiment where experimental treatment is not received in order to give a comparison for the experimental group(s)

Placebo effect

a group thinks they're receiving the treatment, when really they aren't (this is often done with things like sugar pills)

Single-blind procedure

participants don't know which groups receive placebo or actual treatment, but researchers do

Double-blind procedure

neither the researchers nor the participants know which group is given the placebo or actual treatment

Experimenter bias

researchers unintentionally influence study results to match their expectations through biased sample selection, interaction, or data interpretation

Case study

detailed consideration of a particular person/group over a period of time (in-depth, detailed, within real-life context as opposed to lab settings)

Correlation (does not equal causation)

the extent to which two variables are linearly related

Positive correlation

two variables move in the same direction

Negative correlation

two variables move in opposite directions

Directionality problem

it's difficult to establish cause and effect when two things are correlated

Scatterplots

graph used to visualize correlation between variables by plotting dots

Correlation coefficient

numerical measure of correlation (measures strength and direction)

Quantitative measures

statistical/numerical measures to understand behaviors or characteristics

Qualitative measures

non-numerical measures to understand behaviors or characteristics

Framing

cognitive bias where people decide things differently based on whether they're presented with a positive or negative connotation

Social desirability bias

participants answer questions in a way they believe is favorable to others

Meta-analysis

a statistical method that combines and analyzes quantitative data from multiple independent studies in order to draw overall conclusions

Naturalistic observation

observing participants in their natural environment and without intervention

Hypothesis

scientific prediction of what will occur in a study (specific and testable)

Operational definitions

specific, measurable definitions of the variables in a study

Replication and Peer review

replication is the process of redoing a study with similar or new data to verify accuracy

peer review is where experts in the field check over research submissions to verify methodology and validity before publication

Ethical guidelines

rules that must be followed by researchers to make sure no physical or psychological harm is done to the participants

Informed consent

making sure participants know what they're signing up for and they agree to it (risks, duration, procedures, etc.)

Confederates

people secretly working with the researcher, but disguised as a participant

Debriefing

if the participant must be deceived about experimental procedures, they must be informed after the experiment has concluded

Central tendency (mean, median, mode)

describes typical/central values in a data set. mean is average value, median is middle value, mode is most occurring value

Measures of variation (range and standard deviation)

statistics that describe how spread out a set of data is.

range is the difference between the highest and lowest scores.

standard deviation is the average distance of each score from the mean of distribution (small standard deviation means scores are clustered tightly, large standard deviation means scores are spread out)

Normal curve (percentages and percentiles)

a normal curve is a bell-shaped curve that shows how many human traits (such as IQ) cluster around an average value

Positive and negative skews

positive skews are where scores cluster on the low end, negative skews are where scores cluster on the high end

Bimodal distributions

scores cluster around two different values, rather than just one

Regression toward the mean

a statistical phenomenon where when a score is extreme on the first measurement, it tends to be closer to the mean on the second measurement

Cognitive biases (confirmation bias, hindsight bias, overconfidence)

biases that hinder judgement

conformation bias is the tendency to interpret new evidence as confirmation of one's preexisting beliefs

hindsight bias is perceiving past events as more predictable after they've occurred

overconfidence is the overestimation of one's abilities

Nature and nurture

ongoing debate about how much our psychological processes are determined by genetics versus environment

Evolutionary perspective

looking at psychology through the lens of natural selection; used to show how we've evolved over time rather than to show how people are different

Eugenics

scientifically inaccurate theory that said that the human race could be improved through selective breeding (prevented reproduction of the "unfit")

Central nervous system (brain and spine)

receives, processes, and sends information

Peripheral nervous system

nerves outside of the CNS, acting as a communication network between the CNS and the body's skin, muscles, and organs

Somatic nervous system

component of the PNS; voluntary control of skeletal muscles and sensory information

Autonomic nervous system

component of the PNS; involuntary control of internal body functions (heart rate, digestion, respiration, etc.)

Sympathetic vs. parasympathetic nervous system

parts of the autonomic nervous system

sympathetic nervous system gears you up for stress/makes you alert

parasympathetic nervous system calms you down

Glial cell

cells in the nervous system that support, nourish, and protect neurons; also play a role in learning and thinking

Neurons

nerve cells (receive, integrate, and transmit information)

Reflex arc

neural pathway that controls reflexes (involuntary, rapid responses to stimuli)

Sensory neurons

specialized nerve cells that specifically process sensory information from the environment

Motor neurons

specialized nerve cells that transmit impulses from the CNS to muscles, glands, and organs, causing movement

Interneurons

transmit impulses between neurons

Neural transmission

neurons communicate, passing information through the nervous system

All-or-nothing principle

neurons either fire completely or not at all, no in between

Action potential

a brief, rapid reversal of electrical charge across a neuron's membrane that travels down the neuron, acting as the primary signal for communication within the nervous system

Depolarization

a neuron's resting membrane becomes less negative (closer to zero), which causes the neuron to reach threshold and fire action potentials

Refractory period

brief, temporary period of recharge following a stimulus where a neuron cannot fire again

Resting potential

the stable, negative electrical charge across a cell's membrane when it's not sending a signal

Reuptake

the process by which a neuron reabsorbs its own neurotransmitters after it has sent a signal across the synapse

Firing threshold

self-generating action potential is triggered, causing the membrane potential to reverse and become briefly positive

Multiple sclerosis

chronic autoimmune disorder where the body mistakenly attacks the myelin sheath

Myasthenia gravis

chronic, autoimmune disorder causing fluctuating weakness in voluntary muscles

Neurotransmitters (excitatory or inhibitory)

chemical messengers that allow neurons to communicate

excitatory neurotransmitters increase the likelihood of a neuron firing an action potential, promoting neural activity

inhibitory neurotransmitters decrease that likelihood, calming the brain and reducing neural activity

Dopamine

"feel-good" chemical that drives us to seek pleasurable experiences

Serotonin

key neurotransmitter and hormone that regulates mood, sleep, appetite, and cognitive functions

Norepinephrine

hormone involved in "fight or flight" responses

Glutamate

the brain's most abundant neurotransmitter and the primary excitatory chemical, telling neurons to fire and communicate

GABA

the brain's main calming neurotransmitter

Endorphins

natural neurotransmitters and hormones produced by the CNS and the pituitary gland to relieve pain and reduce stress

Substance P

plays a key role in transmitting pain signals, inflammation, and stress responses

Acetylcholine

a vital neurotransmitter in both the CNS and the PNS that facilitates communication between neurons, muscles, and glands. known in psychology for its critical role in memory (linked to Alzheimer's), learning, attention, and muscle contraction

Hormones

chemical messengers from the endocrine system that regulate vital body functions

Adrenaline

a hormone produced by the adrenal glands that triggers the body's fight-or-flight response to stress, fear, or excitement

Leptin

hormone that controls appetite, metabolism, and long-term energy balance

Ghrelin

"hunger hormone" signals brain to increase appetite and consume food

Melatonin

hormone that regulates sleep-wake cycles

Oxytocin

hormone/neurotransmitter associated with empathy, trust, romantic attachment, and maternal instincts; "love hormone"

Agonist vs. antagonist

agonists are chemicals/drugs that activate cell receptors

antagonists are chemicals/drugs that block cell receptors

Reuptake inhibitors

psychoactive drugs that increase levels of neurotransmitters, such as serotonin and dopamine, by blocking their reabsorption back into the neuron

Psychoactive drugs

a chemical substance that alters brain function, resulting in temporary changes in mood, perception, consciousness, or behavior

Stimulants (caffeine, cocaine)

increase activity in the CNS, resulting in enhanced alertness, energy, and mental/physical arousal

Depressants (alcohol)

decrease activity in the CNS, resulting in relaxation, sedation, and lowered anxiety