Psychology Key Concepts

Hub science

Hub science

Psychology's connections to various sciences and approaches

Voluntarism

Emphasizes will and choice in determining thoughts, perceptions, and behaviors

Structuralism

Mental experience broken into smallest elements

Introspection

Personal observation of thoughts, feelings, and behavior

Functionalism

Behavior seen as purposeful and contributing to survival

Behaviorism

Study and measurement of observable behaviors

Biological psychology

Focuses on mind-behavior relationships and underlying biological processes

Evolutionary psychology

Investigates physical structure and behavior shaped by survival and reproduction

Cognitive psychology

Investigates information processing, thinking, reasoning, and problem solving

Developmental psychology

Examines normal behavior changes across the lifespan

Social psychology

Studies effects of social environment on individual behavior

Personality psychology

Individual's characteristic way of thinking, feeling, and behaving

Clinical psychology

Seeks to explain, define, and treat abnormal behaviors

Theory

Set of facts explaining and predicting related phenomena

Hypothesis

Proposed explanation for a situation, usually in 'if A happens, then B' form

Construct

Hypothetical internal attribute useful for describing and explaining behavior

Operational definition

Defining constructs to allow measurement

Independent variable

Experimental variable controlled and manipulated by the experimenter

Dependent variable

Measure demonstrating effects of an independent variable

Descriptive research

Research methods for making careful, systematic observations

Survey

Descriptive method where participants are asked the same questions

Case study

In-depth analysis of behavior of one person or a small number of people

Correlational study

Measure of direction and strength of relationship between two variables

Directionality problem

When cause and effect between two related variables are unknown

Third-variable problem

Variable responsible for a correlation observed between two other variables

Correlation coefficient

Number indicating strength and direction of relationship between variables

Experiment

Research method testing hypotheses and allowing conclusions about causality

Causal claims

Answers to implicit or explicit questions about why or how something occurred

Random assignment

Procedure giving each participant an equal chance of being placed in any group

Random sample

Each member of the population has an equal chance of being chosen to participate

Confound

Irrelevant variable altering researcher's conclusions

Quasi-experiment

Experimental design where random assignment is not possible

Field experiment

Experiment conducted outside of a laboratory setting

External validity

Generalizability of results

Internal validity

Causality of results

Reliability

Consistency of a measure, including test-retest, interrater, and internal consistency

Replication

Repeating an experiment and producing the same results

Descriptive statistics

Methods organizing data into meaningful patterns and summaries

Inferential statistics

Methods extending conclusions from samples to larger populations

Mean

Numerical average of a set of scores

Median

Halfway mark in a set of data, with half the scores above and below

Normal distribution/curve

Symmetrical probability function

WEIRD samples

Western, Educated, Industrialized, Rich, and Democratic samples

Open science

Making science more reproducible, transparent, and robust

Informed consent

Permission obtained from a research participant after thorough explanation of risks and benefits

Research Ethics Board

Committee applying research ethics by reviewing methods for research involving human subjects

Debriefing

Revealing true purpose of a psychology study to a research participant at the conclusion of a study

Animal Care Committee

Committee applying research ethics for animals

Neuron

Cell specialized to send and receive neural messages

Axon

Branch responsible for transmitting information to other neurons

Dendrite

Branch receiving input from other neurons

Myelin sheath

Insulating material covering some axons

Cell body

Large, central mass of a neuron containing the nucleus

Nodes of Ranvier

Periodic gaps in insulating myelin on the axon facilitating rapid conduction of nerve impulses

Action potential

Electrical signal in a neuron's axon

Resting potential

Measure of electrical charge across a neural membrane when not processing information

Synaptic cleft

Point of communication between two neurons

Receptor

Special channel in neuron membrane interacting with neurotransmitters

Neurotransmitters

Chemical messengers communicating across a synapse

Agonist

Drugs enhancing actions of neurotransmitters

Antagonist

Drugs inhibiting actions of neurotransmitters

Reuptake

Process returning neurotransmitter molecules to the axon terminal

Autonomic nervous system (ANS)

Division directing activity of glands, organs, and smooth muscles

Basal ganglia

Collection of subcortical structures controlling movement

Brainstem

Part of the brain containing the midbrain, pons, and medulla

Central nervous system (CNS)

Brain and spinal cord

Cerebellum

Structure participating in skilled movement and complex cognitive processing

Cerebral cortex

Thin layer of neurons covering the cerebral hemispheres

Cingulate cortex

Subcortical structure participating in decision making, emotion, and memory

Corpus callosum

Wide band of nerve fibers connecting the right and left cerebral hemispheres

Endocrine system

System releasing hormones into the bloodstream

Executive functions

Cognitive processes enabling self-regulation and cognitive control

Glia

Nervous system cells performing support functions

GABA

Primary inhibitory neurotransmitter

Glutamate

Primary excitatory neurotransmitter

Serotonin

Affects mood, impulsiveness, hunger, and sleep

Dopamine

Affects reward, motivation, and voluntary movement

Acetylcholine

Affects movement, memory, cognition, and sleep

Epinephrine

Affects stress response and fight or flight

Norepinephrine

Affects stress response and fight or flight

Hippocampus

Subcortical structure participating in memory

Hypothalamus

Subcortical structure participating in regulation of thirst, temperature, hunger, sexual behavior, and aggression

HPA-axis

Parts adjusting hormone balance and affecting stress response

Neurogenesis

Generation of new neurons

Neuroplasticity

Ability of neurons to change in structure and function throughout the lifespan

Nucleus accumbens

Subcortical structure participating in reward and addiction

Occipital lobe

Lobe located at the back of the brain, housing the primary visual cortex

Orbitofrontal cortex

Part of the prefrontal cortex participating in impulse control

Parasympathetic nervous system

Division associated with rest, repair, and energy storage

Parietal lobe

Lobe located at the top of the brain, housing the primary somatosensory cortex

Prefrontal cortex

Most forward part of the frontal lobe, housing areas responsible for complex cognitive processes

Reticular formation

Collection of structures participating in mood, arousal, and sleep

Somatic nervous system

Part of the peripheral nervous system transmitting sensory information and muscle commands

Sympathetic nervous system

Division coordinating arousal

Temporal lobe

Lobe curving around the side of each hemisphere, housing the primary auditory cortex

Thalamus

Subcortical structure involved in processing sensory information, arousal, learning, and memory

Sensation

Process of detecting environmental or body stimuli

Perception

Process of interpreting sensory information

Psychophysics

Study of relationships between physical qualities of stimuli and subjective responses

Signal detection theory

Analysis of sensory and decision-making processes in detecting faint, uncertain stimuli