Introductory Psychology: Research Methods, Neuroscience, Sensation, and Sleep

Comprehensive vocabulary flashcard deck covering research methods, ethics, statistical measures, neuroscience, endocrine signaling, brain regions, genetics, sensory systems, and sleep disorders from the introductory psychology lecture transcript.

Hypothesis

A testable prediction, often implied by a theory, regarding the relationship between two or more variables.

Replication

Repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances.

Operational Definition

A carefully worded statement of the exact procedures and operations used in a research study to define and measure a specific variable.

Case Study

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

Naturalistic Observation

A descriptive research method that involves observing and recording behavior in naturally occurring situations without trying to manipulate or control the setting.

Independent Variable

The experimental factor that is manipulated by the researcher to determine its effect on an outcome.

Dependent Variable

The outcome factor that is measured in an experiment; the variable that may change in response to manipulations of the independent variable.

Confounding Variable

A factor other than the independent variable that might produce an effect in an experiment.

Random Assignment

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

Double-Blind Procedure

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

Placebo Effect

Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition.

Longitudinal Study

A research approach in which the same people are restudied and retested over an extended period of time.

Cross-Sectional Study

A research study in which people of different ages are compared with one another at a single point in time.

Informed Consent

An ethical principle requiring that research participants be given enough information about a study to enable them to choose whether they wish to participate.

Debriefing

The post-experimental explanation of a study, including its purpose and any deceptions, given to participants after the study concludes.

Institutional Review Board (IRB)

An administrative body that reviews proposed research projects involving human subjects to ensure ethical standards and protection from harm are maintained.

Standard Deviation

A computed measure of how much individual scores vary around the mean score.

Normal Distribution

A symmetrical, bell-shaped distribution of data where most scores cluster around the mean and fewer fall near the extremes.

Statistical Significance

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

Correlation Coefficient

A statistical index of the strength and direction of the relationship between two variables, ranging from $-1.0$ to $+1.0$.

Illusory Correlation

The perception of a relationship between two variables where no real relationship exists, or perceiving a relationship as stronger than it actually is.

Dendrite

The branching extensions of a neuron that receive messages and conduct electrical impulses toward the cell body.

Soma (Cell Body)

The central part of the neuron containing the nucleus and life-support machinery of the cell.

Axon

The extended fiber of a neuron that conducts messages away from the cell body toward other neurons, muscles, or glands.

Myelin Sheath

A layer of fatty tissue that insulates the axons of some neurons and accelerates the transmission speed of neural impulses.

Synapse

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

Action Potential

A brief electrical charge that travels down the axon of a neuron when stimulated beyond its threshold.

Refractory Period

A period of inactivity after a neuron has fired, during which it cannot fire another action potential until it resets.

Reuptake

The process by which neurotransmitters in the synaptic gap are reabsorbed back into the sending neuron.

Acetylcholine (ACh)

A neurotransmitter that plays a crucial role in learning, memory, and triggering muscle contractions.

Dopamine

A neurotransmitter that influences voluntary movement, learning, attention, emotion, and pleasure/reward pathways.

Serotonin

A neurotransmitter that regulates mood, hunger, sleep, and emotional arousal.

GABA

The primary inhibitory neurotransmitter in the brain that helps slow down neural activity.

Endorphins

Natural, opiate-like neurotransmitters that alleviate pain and elevate positive feelings or pleasure.

Central Nervous System (CNS)

The division of the nervous system composed exclusively of the brain and the spinal cord.

Peripheral Nervous System (PNS)

The sensory and motor neurons connecting the central nervous system to the rest of the body.

Sympathetic Nervous System

The division of the autonomic nervous system that arouses the body and mobilizes its energy in stressful situations (fight-or-flight response).

Parasympathetic Nervous System

The division of the autonomic nervous system that calms the body and conserves energy, promoting rest and digestion.

Neuroplasticity

The brain's ability to adapt and reorganize neural connections following damage or in response to new experiences.

Hormones

Chemical messengers produced by the endocrine glands that circulate through the bloodstream to affect other tissues and organs.

Cortisol

A steroid hormone secreted by the adrenal glands in response to long-term physical or psychological stress.

Oxytocin

A hormone produced by the hypothalamus and released by the pituitary gland that facilitates social bonding, trust, and maternal behaviors.

Brainstem

The central core and oldest part of the brain, beginning where the spinal cord swells into the skull; governs automatic survival functions.

Medulla

The base of the brainstem that controls involuntary life-support functions, including heartbeat and breathing.

Thalamus

The brain's sensory switchboard, situated atop the brainstem, which directs incoming sensory signals to the appropriate cortex areas.

Cerebellum

The rear structure of the brainstem responsible for coordinating voluntary movement, maintaining balance, and facilitating nonverbal procedural memory.

Limbic System

A neural system located below the cerebral hemispheres, including the hippocampus, amygdala, and hypothalamus, linked to emotions, memory, and drives.

Hypothalamus

A limbic system structure lying below the thalamus that regulates body temperature, hunger, thirst, endocrine activity, and autonomic functions.

Hippocampus

A structure within the limbic system that plays an essential role in the consolidation and processing of explicit, conscious memories.

Amygdala

Two almond-shaped neural clusters in the limbic system that are primarily involved in the processing of emotions such as fear and aggression.

Frontal Lobe

The portion of the cerebral cortex lying behind the forehead, involved in decision-making, planning, muscle movements, and abstract thinking.

Occipital Lobe

The region at the back of the cerebral cortex responsible for processing visual input received from the eyes.

Corpus Callosum

The large band of neural axon fibers connecting the left and right cerebral hemispheres, enabling communication between them.

EEG (Electroencephalogram)

A brain imaging technique that records continuous electrical brainwave activity using electrodes placed on the scalp.

PET Scan

A neuroimaging technique that maps brain activity by tracking the consumption of a temporarily injected radioactive form of glucose.

fMRI

A functional brain imaging technique that reveals real-time blood flow and neural activity by comparing successive MRI scans.

Natural Selection

The evolutionary process whereby inherited variations that increase an organism's reproductive and survival chances are more likely to be passed on to future generations.

Epigenetics

The study of changes in gene expression or cellular phenotype caused by environmental mechanisms without altering the underlying DNA sequence.

Sensation

The physical process by which our sensory receptors and nervous system detect and receive stimulus energies from our external environment.

Perception

The cognitive process of organizing, recognizing, and interpreting sensory information to formulate meaningful mental representations.

Olfaction - Smell

The sensory system and physical sense responsible for detecting and processing chemical odor molecules.

Gustation - Taste

The sensory modality responsible for detecting dissolved chemical compounds through taste receptor cells on the tongue.

REM Sleep

The rapid eye movement phase of the sleep cycle characterized by high brain activity, vivid dreaming, and temporary skeletal muscle paralysis.

Sleep Apnea

A serious sleep disorder characterized by repeated, temporary cessations of breathing during sleep that result in momentary awakenings.

Narcolepsy

A chronic neurological sleep disorder characterized by overwhelming daytime drowsiness and sudden, uncontrollable lapses directly into sleep or REM states.

Night Terrors

A sleep disturbance characterized by high physiological arousal and intense feelings of terror, typically occurring during NREM-3 deep sleep rather than REM sleep.

Population

The entire group of individuals from which researchers draw samples and to whom conclusions are meant to apply.

Sample

A selected subgroup drawn from a larger target group, studied to draw inferences about the whole.

Random Sample

A representative selection of participants chosen such that every individual in the target group has an equal probability of selection.

Survey

A descriptive research method that gathers self-reported attitudes, beliefs, or behaviors from a large group of people.

Interview

A qualitative data-collection method involving structured or semi-structured verbal questioning of individual participants.

Correlational Study

A non-experimental research design that assesses the statistical relationship and pattern of association between two or more variables.

Experiment

A rigorous research method in which an investigator manipulates one factor while holding other conditions constant to determine cause-and-effect relationships.

Experimental Group

The cohort of research participants exposed to the active treatment or manipulation under investigation.

Control Group

The cohort of research participants that does not receive the experimental treatment, providing a baseline comparison.

Single-Blind Procedure

A research design where participants do not know whether they are receiving the active treatment or a placebo, while researchers remain aware.

Experimenter Bias

The phenomenon where an investigator's expectations or preferences unintentionally influence participant behavior or the recording of data.

Qualitative Data

Non-numerical descriptive information that captures subjective qualities, personal narratives, and experiential details.

Quantitative Data

Empirical information expressed in numerical values that can be systematically categorized, counted, and statistically analyzed.

Generalization

The extent to which experimental results obtained from a study cohort can be accurately extended to broader populations or settings.

Peer Review

A formal evaluation process where academic experts critically evaluate an author's methodology, data, and conclusions before publication.

Confidentiality

An ethical research requirement ensuring that participants' personal identities, responses, and records remain private and shielded from disclosure.

Protection from Harm

An ethical standard mandating that researchers ensure participants are shielded from physical injury, lasting distress, and psychological damage.

Mean

A measure of central tendency determined by calculating the arithmetic average of all scores in a distribution.

Median

A measure of central tendency representing the exact midpoint score that divides an ordered data set into two equal halves.

Range

A measure of dispersion calculated as the difference between the highest and lowest scores in a data set.

Distribution

The overall frequency pattern showing how individual scores are arranged across possible values in a data set.

Skewed Distribution

An asymmetrical frequency spread where disproportionate outlier scores pull the tail toward one extreme.

Variability

The degree of spread, dispersion, or clustering among individual scores around the central value of a data set.

Correlation

A statistical measurement indicating the degree to which two or more variables systematically covary.

Positive Correlation

A relationship between two variables wherein both variables increase or decrease in the same direction.

Negative Correlation

An inverse relationship between two variables where an increase in one corresponds to a decrease in the other.

Neuron

A specialized nerve cell that conducts electrochemical impulses throughout the body to process and transmit information.

Terminal Buttons

The knob-like structures at the ends of axon branches that release chemical messengers into the synaptic cleft.

Threshold

The minimum level of electrical stimulation required to trigger an all-or-none action potential in a nerve cell.

Neurotransmitter

A chemical substance released by a presynaptic axon terminal that traverses the microscopic gap to bind with target receptors.

Agonist

A chemical substance or pharmaceutical agent that binds to a receptor and mimics or amplifies the natural physiological response.

Norepinephrine

A dual-function neurochemical that modulates physical arousal, alertness, vigilance, and the sympathetic fight-or-flight response.

Glutamate

The primary excitatory chemical messenger in the central nervous system, playing a critical role in learning and long-term potentiation.

Adrenaline (Epinephrine)

A hormone and neurochemical released by the adrenal glands during acute stress to accelerate heart rate, dilate airways, and increase blood sugar.