Introductory Psychology: Research Methods, Biological Bases, Sensation, Perception, and Cognition

Comprehensive vocabulary flashcards covering psychological research methods, neuroanatomy, neurotransmitters, sensory systems, sleep stages and disorders, depth perception, cognitive heuristics, and Gestalt principles.

Anecdotal evidence

Casually observed incidents that are accepted as useful information; scientifically inadequate, but can offer clues as to areas of investigation that warrant more systematic, controlled research.

Between-subjects design

A study in which individuals are assigned to only one treatment or experimental condition and each person provides only one score for data analysis.

Within-subjects design

An experimental design in which the effects of treatments are seen through the comparison of scores of the same participant observed under all the treatment conditions.

Causal ambiguity

Also known as the third-variable problem; a situation in which it is not known which one (or which set) of several phenomena is the cause of a particular effect.

Correlation coefficient

A numerical index reflecting the degree of a linear relationship between two variables (where $+1$ indicates a perfect positive relationship and $-1$ indicates a perfect negative relationship).

Counterbalancing

Arranging a series of experimental conditions or treatments in such a way as to minimize the influence of extraneous factors, such as practice or fatigue, on experimental results.

Demand characteristics

In an experiment or research project, cues that may influence or bias participants' behavior, for example, by suggesting the outcome or response that the experimenter expects or desires.

Quasi-experimental design

An experimental design in which assignment of participants to an experimental group or to a control group cannot be made at random for either practical or ethical reasons; assignment of participants to conditions is usually based on self-selection or selection by an administrator.

Confounding variable

An independent variable that is conceptually distinct but empirically inseparable from one or more other independent variables.

False consensus effect

The tendency of how individuals frequently overestimate how much others share their beliefs, values, and behaviors; people project their personal ideas and attitudes onto others, assuming they are more common and widespread than they actually are.

Hindsight bias

The tendency, after an event has occurred, to overestimate the extent to which the outcome could have been foreseen.

Meta analysis

A quantitative technique for synthesizing the results of multiple studies of a phenomenon into a single study.

Null hypothesis

A statement that a study will find no meaningful differences between the groups or conditions under investigation, such that there is no relationship among the variables of interest and that any variation in observed data is the result of chance or random processes.

Operational definition

A description of something in terms of the operations (procedures, actions, or processes) by which it could be observed and measured.

Principle of falsifiability

The logical possibility that an assertion, hypothesis, or theory can be shown to be false by an observation or experiment.

Standard score

Also known as z-score; a set of scores that have the same mean and standard deviation so they can be compared.

p-Value

Also known as probability value; a number describing the likelihood of obtaining the observed data under the null hypothesis of a statistical test.

Acetylcholine

Neurotransmitter that plays an important role in memory, learning, attention, arousal, and involuntary muscle movement.

Dopamine

Neurotransmitter that plays a role as a "reward center" and in memory, movement, motivation, mood, and attention.

GABA

Inhibitory neurotransmitter that lessens a neuron's ability to receive, create, or send chemical messages to other neurons; produces a calming effect.

Agonist

A substance like heroin that mimics the actions of a neurotransmitter or hormone to produce a response when it binds to a specific receptor in the brain.

Antagonist

A substance like naltrexone that binds to a specific receptor in the brain but does not activate it.

All-or-nothing principle

Signal transmission between neurons is not dependent on the strength of the stimuli, but only that the initial threshold is met; neurons will either transmit an impulse over the synapse to the next neuron or not.

Amygdala

Major processing center for emotions, linking emotions to other functions like memories and learning; fear is the main emotion it controls.

Thalamus

The brain's information relay station; all information from body senses (except smell) is processed through it before being sent to the cerebral cortex for processing; also plays a role in sleep, wakefulness, consciousness, learning, and memory.

Hypothalamus

Main function is to keep the body in a stable state (homeostasis) by directly influencing the autonomic nervous system or managing hormones; relates to body temperature, blood pressure, hunger and thirst, fullness when eating, mood, sex drive, and sleep.

Hippocampus

Brain structure responsible for memory and learning; short- and long-term memory, as well as awareness from the environment.

Broca's area

Region of the brain containing neurons involved in speech function, discovered in 1861 by French surgeon Paul Broca; along with the motor cortex, it controls the ability to speak.

Wernicke's area

Region of the brain containing neurons involved in language development, discovered in 1874 by German neurologist Carl Wernicke; controls the ability to understand the meaning of words.

Corpus callosum

Large white matter tract that connects the two hemispheres of the brain; allows for depth perception and enables the two sides of the brain to communicate.

Functional magnetic resonance imaging (fMRI)

Medical imaging scan that shows activity in specific areas of the brain using a powerful magnet, radio waves, and computer processing by tracking blood flow to different parts of the brain.

Electroencephalogram (EEG)

Test that measures electrical activity in the brain by using small, metal discs called electrodes attached to the scalp; brain cells communicate via electrical impulses, showing activity as wavy lines.

Heritability coefficient

The ratio of genetic variance to phenotypic variance, ranging from $0$ to $1$; a value close to $0$ indicates variability is due to environmental factors, whereas a value of $0.5$ indicates half of the phenotypic variation is due to genetic variation.

Reticular activating system

A network of neurons located in the brainstem that plays a fundamental role in regulating arousal and sleep-wake transitions; enhances the attentive state of the cortex and facilitates conscious perception of sensory stimuli.

Plasticity

In the brain, the capacity of the nervous system to change its structure and ultimately its function over a lifetime.

Action potential

Rapid rise and fall in voltage across a cellular membrane with a characteristic pattern.

Absolute threshold

Smallest level of stimulus that can be detected, usually defined as detectable at least half of the time.

Signal-detection theory

The concept that the intensity of stimuli and the psychological and physical state of a person contribute to whether or not the person is able to detect the stimuli.

Activation-synthesis theory

Hypothesis that explains dreams as a product of cortical interpretation of random neural activity rising from the brainstem (specifically the pons).

Circadian rhythm

Any periodic variation in physiological or behavioral activity that repeats at approximately 24-hour intervals.

Blindsight

Ability of people who are cortically blind (damage to the brain's occipital lobe) to respond to visual stimuli that they do not consciously see due to lesions in the primary visual cortex.

Weber's law

States that the change in a stimulus that will be just noticeable is a constant ratio of the original stimulus.

Gate-control theory

Concept that neurological gateways in the brain decide which pain signals come through and which are kept out; when gates are open, more pain is felt; when closed, less pain is felt.

Narcolepsy

A disorder consisting of excessive daytime sleepiness accompanied by brief "attacks" of sleep during waking hours, featuring immediate entry into REM sleep without going through initial stages.

Sleep apnea

The temporary cessation of breathing while asleep, occurring when the upper airway briefly becomes blocked (obstructive) or when respiratory centers in the brain fail to stimulate respiration (central).

REM sleep disorder

Also known as REM behavior disorder; a sleep disorder involving motor activity during REM sleep that typically includes physical enactment of dream sequences, which can be disruptive and violent.

Opponent-process theory

Theory that the ability to perceive color is controlled by three receptor complexes with opposing actions (red-green, blue-yellow, and black-white); the mind can only register one color of a pair at a time.

Trichromatic theory

Theory that human eyes only perceive three colors of light—red, blue, and green—whose wavelengths can be combined to create every color on the visual light spectrum.

Presbyopia

Gradual loss of the eye's ability to focus on nearby objects as a normal part of aging, occurring because the lens hardens, becomes less flexible, and stops focusing light correctly on the retina.

Prosopagnosia

"Face blindness"; a condition in which the brain cannot recognize faces or facial expressions in spite of normal vision, most commonly caused by brain injury or genetics.

Rods

Tall, cylindrical photoreceptors that make up $95\%$ of all photoreceptors; extremely sensitive to tiny amounts of light and responsible for low-light vision, but unable to detect colors or fine details.

Cones

Cone-shaped photoreceptors clustered mostly in the macula of the retina; require more light to activate than rods, discern fine details, and detect light wavelengths to allow the brain to perceive color.

Sleep paralysis

Brief inability to move or speak just before falling asleep or upon awakening, often accompanied by terrifying hallucinations; may involve temporary dysfunction of the reticular activating system.

Somnambulism

Also known as sleepwalking disorder; persistent incidents of complex motor activity during slow-wave NREM sleep, typically occurring in the first hours of sleep with unresponsiveness and amnesia for the episode.

REM sleep

Rapid-eye movement sleep; the stage of sleep in which most dreaming occurs, marked by wakefulness-like EEG activity, inhibition of most skeletal and cranial muscles, and accounting for $20\text{--}25\%$ of sleep.

Synesthesia

Phenomenon that causes sensory crossovers, such as tasting colors or feeling sounds; not a disease, but can be a symptom of certain brain-related conditions.

Transduction

The process that converts a sensory signal into an electric signal to be processed in a specialized area in the brain.

Basilar membrane

The main mechanical element of the inner ear; its vibration patterns separate incoming sound into component frequencies that activate different cochlear regions.

Vestibular sense

Sensory system providing the sense of balance and information about body position, allowing rapid compensatory movements in response to forces.

Linear perspective

The system of creating an illusion of depth on a flat surface whereby all parallel lines in a painting or drawing converge in a single vanishing point on the composition's horizon line.

Algorithm

A defined set of step-by-step procedures that provides the correct answer to a particular problem.

Availability heuristic

Mental shortcut that relies on immediate examples that come to one's mind when evaluating a specific topic, method, or decision.

Representativeness heuristic

Mental shortcut where decisions are based on comparisons to mental representations of stereotypes, prototypes, or preconceived outcomes.

Anchoring heuristic

Mental shortcut that causes people to favor information they received early in the decision-making process.

Confirmation bias

Cognitive bias where an individual only seeks out information that supports their position or idea.

Bottom-up processing

Perception driven by the external stimulus itself, where sensory data is interpreted based on its inherent properties without relying on pre-existing knowledge or concepts.

Top-down processing

Perception driven by prior experience and knowledge; using something already known to make sense of new information.

Color constancy

The ability to perceive colors as relatively constant across varying light sources.

Divergent thinking

Utilizing the mind in inventive, free-flowing ways to solve a given problem and find multiple creative solutions.

Feature detectors

Individual neurons or groups of neurons in the brain that code for perceptually significant stimuli by responding to specific features like shape, angle, or movement.

Functional fixation

Also known as functional fixedness; the tendency to perceive an object only in terms of its most common use.

Law of Prägnanz

Gestalt principle stating that people tend to perceive forms as the simplest, most meaningful, stable, and complete structures that conditions permit.

Phi phenomenon

Also known as stroboscopic motion; an illusion of movement that arises when stationary objects like lightbulbs are placed side-by-side and illuminated rapidly one after another.

Parallel processing

The ability to deal with multiple stimuli simultaneously and unconsciously, such as driving while listening to music and observing signs.

Perceptual set

A predisposition to notice some aspects of available sensory data while ignoring others; a cognitive bias affecting interpretation based on expectations and past experiences.

Subliminal stimuli

Any sensory stimuli below an individual's threshold for conscious perception that activate specific regions of the brain despite lack of awareness.