All Terms

Confirmation Bias

The tendency to search for, interpret, and remember information in a way that confirms one’s preexisting beliefs.

Hindsight Bias

The inclination to see events as having been predictable after they have already occurred.

Overconfidence

The tendency to overestimate one’s abilities, knowledge, or predictive capabilities.

Independent Variable

The variable that is manipulated in an experiment to see its effect on the dependent variable.

Dependent Variable

The variable that is measured in an experiment to see how it is affected by the independent variable.

Random Assignment

The process of randomly assigning participants to different groups to ensure each has an equal chance of being in any group.

Case Study

An in-depth examination of an individual or a small group, often used in psychological research.

Correlation

A statistical measure that indicates the extent to which two variables fluctuate together.

Meta-Analysis

A statistical analysis that combines the results of multiple scientific studies.

Naturalistic Observation

A research method involving observing subjects in their natural environment without manipulation.

Hypothesis

A testable prediction about the relationship between two or more variables.

Falsifiable Hypothesis

A hypothesis that can be proven false through evidence or experimentation.

Operational Definitions

Specific explanations of abstract concepts that a researcher plans to study.

Confounding Variables

Variables that may affect the dependent variable outside of the independent variable.

Histogram

A graphical representation showing the distribution of a dataset.

Scatterplot

A graph that displays values for typically two variables for a set of data.

Central Tendency

A statistical summary that represents the central point of a dataset.

Variation

A measure of how much values in a dataset differ from each other.

Percentile Rank

A score that indicates the percentage of scores that fall below a particular value.

Range

The difference between the highest and lowest values in a dataset.

Standard Normal Curve

A bell-shaped curve representing the distribution of a set of data.

Mean

The average value of a dataset, calculated by adding all numbers and dividing by the count.

Median

The middle value in a dataset when the values are arranged in order.

Mode

The value that appears most frequently in a dataset.

Standard Deviation

A measure of the amount of variation or dispersion in a set of values.

Regression Toward the Mean

The tendency for extreme values to return to the average over time.

Population

The entire group of individuals that a researcher is interested in studying.

Representative Sample

A subset of the population that accurately reflects the members of the entire population.

Random Sample

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

Convenience Sampling

Choosing individuals who are easiest to reach for a study.

Sampling Bias

A bias that occurs when a sample is not representative of the population from which it is drawn.

Generalization

The process of applying findings from a study to a broader context.

Experimental Group

The group in an experiment that receives the treatment or intervention being tested.

Control Group

The group in an experiment that does not receive the treatment and is used as a benchmark.

Placebo

A substance or treatment with no therapeutic effect, used as a control in testing new drugs.

Single-Blind Study

A study in which the participants do not know which group they are in.

Double-Blind Study

A study in which neither the participants nor the experimenters know who is receiving a particular treatment.

Experimenter Bias

A cognitive bias that occurs when researchers influence the outcome of their study.

Social Desirability Bias

The tendency for participants to answer questions in a manner that will be viewed favorably by others.

Qualitative Measures

Data that are descriptive and conceptual, focused on qualities rather than quantities.

Quantitative Measures

Data that can be quantified and assessed statistically.

Peer Review

A process in which scholars evaluate research before it is published.

Statistical Significance

A measure of whether results are likely due to chance or if they are meaningful.

Correlation does NOT equal causation

A statement that indicates that a correlation between two variables does not imply that one causes the other.

Self-Report Bias

A bias that occurs when individuals provide inaccurate data about themselves.

Institutional Review Board

A committee that reviews research proposals to ensure ethical standards are met.

Animal Research Ethical Standards

Guidelines that govern the ethical treatment of animals in research.

Informed Consent

The process of getting permission before conducting a healthcare intervention on a person.

Protection from Harm

An ethical principle requiring that participants in research not be exposed to unnecessary risks.

Confidentiality

The ethical duty to protect the privacy of research participants.

Deception

The practice of misleading participants about the true purpose of a study.

Debriefing

The process of informing participants about the study's purpose and any deceptions after their participation.

Heredity vs. Environment

The debate regarding the relative contributions of genetic inheritance and environmental factors to human development.

Twin Studies

Research designs that involve twins to understand the influence of genetics versus environment.

Central Nervous System

The part of the nervous system that includes the brain and spinal cord.

Peripheral Nervous System

The part of the nervous system that includes all the neural elements outside of the central nervous system.

Autonomic Nervous System

The division of the peripheral nervous system that controls involuntary bodily functions.

Somatic Nervous System

The division of the peripheral nervous system that coordinates voluntary muscle movements.

Neurons

The basic building blocks of the nervous system; cells that transmit information throughout the body.

Glial Cells

Non-neuronal cells in the nervous system that provide support and protection for neurons.

Spinal Cord Reflex

An involuntary response to a stimulus that is processed in the spinal cord.

Sensory Neurons

Nerve cells that transmit sensory information from the periphery of the body to the central nervous system.

Motor Neurons

Nerve cells that carry signals from the central nervous system to muscles to produce movement.

Interneurons

Neurons that communicate between sensory and motor neurons; involved in reflexes.

All or Nothing Principle

The principle stating that once the threshold is reached, a neuron will fire completely or not at all.

Depolarization

The process by which the membrane potential of a neuron becomes positive.

Refractory Period

A short period following the firing of a neuron during which it cannot fire again.

Resting Potential

The electrical potential of a neuron at rest, typically around -70 millivolts.

Reuptake

The process of absorbing neurotransmitters back into the presynaptic neuron after they have done their work.

Threshold

The level of stimulation required to trigger a neural impulse.

Multiple Sclerosis

A disease that affects the central nervous system, leading to a breakdown of the myelin sheath covering neurons.

Myasthenia Gravis

An autoimmune disorder that leads to weakness in the skeletal muscles.

Medulla

The base of the brainstem responsible for regulating vital functions such as heartbeat and breathing.

Cerebellum

A portion of the brain that plays an important role in motor control.

Cerebral Cortex

The outer layer of the brain, associated with higher brain functions like thought and action.

Thalamus

The brain's relay station, directing sensory information to the appropriate areas of the cortex.

Hypothalamus

The brain region controlling the pituitary gland and regulating many body functions, including hunger and thirst.

Pituitary Gland

The endocrine gland that controls other glands and regulates growth, metabolism, and stress.

Hippocampus

A brain structure involved in learning and memory.

Amygdala

A brain structure involved in processing emotions, particularly fear.

Corpus Callosum

The large band of neural fibers connecting the two brain hemispheres and carrying messages between them.

Occipital Lobe

The visual processing center of the brain.

Temporal Lobe

The region of the brain associated with hearing, memory, and emotion.

Parietal Lobe

The brain region responsible for processing sensory information regarding the location of parts of the body.

Frontal Lobe

The area of the brain that controls thought processes, reasoning, and voluntary movements.

Split Brain Research

Studies that explore the effects and implications of separating the two hemispheres of the brain.

Epilepsy

A neurological disorder characterized by recurrent seizures.

Broca’s Area

A brain region associated with language processing and speech production.

Wernicke’s Area

A brain region involved in understanding spoken and written language.

Aphasia

A language disorder resulting from brain damage, affecting the production or comprehension of speech.

Contralateral Hemispheric Organization

The principle that the right hemisphere of the brain controls the left side of the body and vice versa.

Brain Plasticity

The brain's ability to adapt and reorganize itself, especially after injury.

EEG

A technique that measures electrical activity in the brain.

fMRI

A technique for measuring brain activity by detecting changes associated with blood flow.

Lesioning

The process of destroying or removing brain tissue to study effects on behavior.

Neurotransmitters

Chemicals that transmit signals across a synapse from one neuron to another.

Dopamine

A neurotransmitter associated with reward and pleasure.

Serotonin

A neurotransmitter that stabilizes mood, feelings of well-being, and happiness.

Norepinephrine

A neurotransmitter involved in arousal and alertness.

Glutamate

The major excitatory neurotransmitter in the brain.