Comprehensive Psychology Study Guide: Research Methods, Neuroscience, Sensation, Learning, and Memory

Independent Variable ($\text{IV}$)

The experimental factor systematically manipulated or controlled by the researcher to determine its effect.

Dependent Variable ($\text{DV}$)

The measured outcome factor that changes in direct response to manipulations of the independent variable.

External Validity

The degree to which experimental findings mirror real-world settings and can be generalized beyond the laboratory.

Corpus Callosum

A thick band of nerve fibers connecting the left and right cerebral hemispheres, enabling interhemispheric communication.

Afferent Nerves

Sensory pathways that carry environmental and physiological information from the body inward to the central nervous system.

Efferent Nerves

Motor pathways that carry instructional commands outward from the central nervous system to muscles and effectors.

Sympathetic Nervous System

The division of the autonomic nervous system that mobilizes the body during emergencies, mediating the fight, flight, or freeze response.

Parasympathetic Nervous System

The division of the autonomic nervous system responsible for internal recuperation, homeostatic balance, and resting states.

Action Potential

A rapid electrical impulse propagating along an axon membrane driven by the movement of sodium ($\text{Na}^+$) and potassium ($\text{K}^+$) ions.

Absolute Threshold

The minimum amount of physical stimulus energy an individual can reliably detect.

Weber's Law

The psychophysical principle that two stimuli must differ by a constant minimum percentage rather than a constant fixed amount to be perceived as distinct.

Classical Conditioning

A form of associative learning where a neutral conditioned stimulus is paired with an unconditioned stimulus to elicit an involuntary reflex.

Operant Conditioning

A form of learning pioneered by B.F. Skinner where voluntary behaviors are shaped and modified by their reinforcing or punishing consequences.

Negative Reinforcement

The removal or avoidance of an unpleasant stimulus following a target behavior, increasing the future probability of that behavior.

Observational Learning

A learning framework developed by Albert Bandura where individuals acquire behaviors by attending to, retaining, and imitating social models.

Explicit Memory

The conscious, declarative recollection of factual information, general knowledge, and personal life events.

Implicit Memory

The non-declarative, unconscious memory responsible for procedural motor skills, physical habits, and conditioned reflexes.

Proactive Interference

A memory failure that occurs when older, previously learned memories disrupt the retrieval of newly acquired information.

Retroactive Interference

A memory failure that occurs when newly learned information interferes with the retrieval of older, previously stored memories.