General Psychology: Research Methods, Sensation, and Perception

Flashcards covering research methodology, experimental controls, ethics, sensory biology, visual pathways, color theories, Gestalt principles, depth cues, and audition based on lecture notes.

Psychology

The scientific study of mind and behavior.

Empirical Question

A question that can be answered through objective observation, measurement, and experimentation.

Objectivity

The practice of basing research conclusions on facts without the influence of personal emotion or bias.

Confirmation Bias

The tendency to notice and recall information that supports pre-existing beliefs while ignoring or overlooking evidence that contradicts them.

Theory

A set of interconnected ideas and concepts that explains what is observed in behavior or the natural world.

Hypothesis

A specific, testable prediction derived directly from a theory that specifies what should happen under given conditions.

Deductive Reasoning

A scientific reasoning process that begins with a broad theory, derives a specific hypothesis, and tests it against empirical observations.

Inductive Reasoning

A scientific reasoning process that moves from specific real-world empirical observations to noticed patterns, forming generalized hypotheses and theories.

Falsifiability

The requirement that a scientific theory must make definite, testable predictions about future events that can potentially be proven wrong.

Parsimony (Occam's Razor)

The scientific principle stating that when two theories fit all available evidence equally well, the simplest explanation with the fewest assumptions should be favored.

Peer Review

The evaluation process where independent experts in the same scientific field examine and scrutinize a study prior to publication.

Replication

The independent repetition of an experimental study by other researchers to verify whether the original findings can be reproduced.

Case Study

A descriptive research method involving an in-depth, detailed analysis of a single individual or a small group.

Survey

A descriptive research technique in which a large group of respondents answer structured questions about their attitudes, opinions, or behaviors.

Naturalistic Observation

An observational method involving the systematic study of subjects in their natural environment without researcher intervention.

Archival Research

A descriptive research method that analyzes pre-existing data sets and historical records (e.g., medical databases or registries) to explore patterns.

Population

The entire group of interest from which a research sample is drawn and to which study conclusions are meant to apply.

Sample

A representative subset of a larger population selected to participate in a research study.

Variable

Any factor, property, or characteristic that can take on a range of measurable values.

Measure

A standardized method or assessment tool used to describe and quantify the value or amount of a variable.

Third Variable

An unmeasured external factor responsible for an observed statistical correlation between two other variables of interest.

Correlation

A measure of the directional relationship and association between two variables that are outside of the researcher's direct control.

Correlation Coefficient

A mathematical value ranging from $-1.0$ to $+1.0$ that indicates the strength and direction of the relationship between two variables.

Experiment

A research method where the investigator deliberately manipulates at least one variable to determine its causal effect on another measured variable.

Independent Variable (IV)

The variable in an experiment that is controlled and manipulated by the experimenter to test its effects.

Dependent Variable (DV)

The variable in an experiment measured by the researcher to assess the impact of manipulating the independent variable.

Random Assignment

A procedure in experiments that uses chance to ensure every participant has an equal probability of being assigned to any experimental condition.

Operational Definition

A precise definition specifying the exact physical steps, procedures, or measurements used to create and quantify a research variable.

Confounding Variable

An extrinsic variable that systematically covaries with the independent variable, introducing alternative explanations for the results.

Placebo Effect

A change in a participant's behavior or physiological response caused by their expectations rather than an active treatment.

Double-Blind Procedure

An experimental safeguard in which neither the participants nor the researchers collecting data know who is assigned to the experimental or control conditions.

Cross-Sectional Study

A research design that compares data collected simultaneously from subjects of different age groups.

Cohort Effect

A potential confounding influence in cross-sectional research arising from generational differences in historical or cultural experiences.

Longitudinal Study

A research design in which the same individual participants are repeatedly observed and tested over an extended period.

Attrition

The progressive loss of subjects over time in longitudinal research due to relocation, illness, drop-out, or death.

Attrition Bias

A methodological threat that occurs when a specific sub-demographic drops out of a longitudinal study faster than others, harming generalizability.

Meta-Analysis

A statistical procedure that combines and synthesizes data across multiple independent studies on the same topic to determine overall trends.

Validity

The degree to which a research tool, test, or experiment accurately measures what it claims to measure.

Reliability

The consistency and stability of a measurement tool across repeated tests or across different raters.

Normal Distribution

A symmetrical, bell-shaped continuous probability distribution where scores cluster centrally around the mean.

Null Hypothesis

A baseline statistical assumption stating that there is no real difference or true effect between experimental conditions.

Statistical Significance

A mathematical criterion used to determine whether an observed outcome is unlikely to have occurred by random chance under a true null hypothesis.

Institutional Review Board (IRB)

An administrative committee charged with evaluating human research proposals to ensure ethical compliance and participant safety.

Institutional Animal Care and Use Committee (IACUC)

An institutional oversight body responsible for reviewing animal research proposals to ensure humane care and minimal suffering.

Sensation

The biological process by which sensory receptors detect environmental energy and convert it into neural signals.

Perception

The cognitive process of organizing, identifying, and interpreting sensory information to form a meaningful mental representation.

Transduction

The conversion of physical sensory energy into electrical neural impulses (action potentials) usable by the nervous system.

Absolute Threshold

The minimum stimulus energy needed for a sensory system to detect its presence $50\%$ of the time.

Just Noticeable Difference (JND)

The minimum difference in physical intensity required to detect a change between two stimuli.

Weber's Law

A psychophysical principle stating that the difference threshold is a constant fraction of the initial stimulus magnitude.

Cornea

The clear, protective outer surface at the front of the eye that refracts light toward the retina.

Pupil

The adjustable circular opening in the center of the iris through which light enters the interior of the eye.

Iris

The colored circular muscle surrounding the pupil that contracts or expands to regulate light intake.

Lens

The clear structure situated behind the pupil that bends and fine-tunes light rays to focus images on the retina.

Retina

The light-sensitive tissue lining the back of the eye containing photoreceptor cells and visual processing circuits.

Fovea

A specialized central region of the retina densely packed with cones that provides high-acuity central vision.

Cones

Photoreceptors concentrated in the fovea that function under bright lighting and are responsible for color vision and high spatial resolution.

Rods

Photoreceptors distributed across the retinal periphery that are specialized for low-light vision, motion detection, and peripheral awareness.

Blind Spot

The region on the retina where ganglion cell axons join to form the optic nerve, completely lacking photoreceptors.

Optic Nerve

The neural bundle formed by axons of retinal ganglion cells that transmits visual information from the eye to the brain.

Optic Chiasm

The X-shaped junction where visual fibers from the nasal side of each retina cross over to the opposite cerebral hemisphere.

Ventral Stream ('What' Pathway)

The visual pathway extending into the temporal lobe that processes object identity, form, color, and facial recognition.

Dorsal Stream ('Where/How' Pathway)

The visual pathway extending into the parietal lobe that processes motion, spatial location, and visual guidance for action.

Trichromatic Theory (Young-Helmholtz Theory)

The theory stating that color vision relies on the relative activation rates of three cone types sensitive to short (blue), medium (green), or long (red) wavelengths.

Opponent-Process Theory

The theory proposing that color vision is processed through paired opposing mechanisms ($Red\text{ vs. }Green$, $Yellow\text{ vs. }Blue$, $White\text{ vs. }Black$).

Sensory Adaptation

The reduction in sensory receptor firing rate and sensitivity following continuous, prolonged exposure to an unchanging stimulus.

Retinex Theory

A color vision theory explaining color constancy by asserting that cortical visual neurons compare light patterns across different regions of the retina.

Color Constancy

The perceptual tendency for an object to appear as a constant color despite significant changes in ambient illumination.

Bottom-Up Processing

Perceptual processing driven directly by raw incoming sensory data from the environment without higher-level expectations.

Top-Down Processing

Perceptual processing guided by high-level cognitive processes, including memories, expectations, knowledge, and context.

Inattentional Blindness

The failure to perceive a completely visible, unexpected object because attention is fully directed elsewhere.

Perceptual Set

A mental predisposition or expectation shaped by prior experience, culture, and context that biases how sensory data is interpreted.

Gestalt Principles

A set of perceptual rules describing how the human brain naturally organizes isolated visual elements into coherent, structured wholes.

Convergence

A binocular depth cue involving the inward physical rotation of the eyes when focusing on an object close to the observer.

Retinal Disparity

A binocular depth cue based on the slight difference between the two-dimensional images projected onto the left and right retinas.

Motion Parallax

A monocular dynamic depth cue where objects closer to a moving observer pass by rapidly, while distant objects appear to move slowly.

Müller-Lyer Illusion

A visual illusion where two lines of equal length appear unequal due to arrow-fin orientations triggering top-down depth interpretations.

Audition

The sense of hearing, involving the biological transduction of physical sound waves into neural signals.

Pinna

The visible external structure of the outer ear that collects and funnels sound waves into the auditory canal.

Tympanic Membrane (Eardrum)

The flexible membrane separating the outer and middle ear that vibrates in response to incoming sound waves.

Cochlea

The fluid-filled, snail-shell-shaped organ of the inner ear containing receptor hair cells that transduce sound waves into neural signals.

Basilar Membrane

The flexible membrane running through the cochlea that supports hair cells and moves in response to fluid vibrations.

Equal-Loudness Contour

A curve showing the required sound pressure level ($dB\text{ SPL}$) across frequencies to maintain a constant level of perceived loudness.

Place Theory

An auditory pitch theory stating that pitch perception corresponds to the specific location along the basilar membrane showing maximum vibration.

Temporal Theory

An auditory pitch theory proposing that pitch is determined by the rate of neural firing matching the physical frequency of a sound wave.