AP Psychology: Sensation, Perception, and States of Consciousness

Comprehensive practice flashcards defining core vocabulary terms across sensory interaction, vision, audition, chemical and body senses, states of consciousness, sleep, and psychophysics.

Sensory Interaction

The principle that one sense may influence another, such as when the smell of food influences its taste.

Synesthesia

A rare condition where stimulation of one sensory pathway leads to involuntary experiences in a second sensory pathway, resulting in blended sensations (such as seeing colors when hearing music).

Wavelength

The distance from the peak of one light wave or sound wave to the peak of the next.

Hue

The dimension of color that is determined by the wavelength of light, corresponding to color names such as blue and green.

Intensity

The amount of energy in a light wave or sound wave, perceived as brightness or loudness and determined by the wave's height.

Cornea

The eye's clear, protective outer layer that covers the pupil and iris.

Pupil

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

Iris

A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening.

Lens

The transparent structure behind the pupil that changes shape to help focus images on the retina.

Accommodation

The process by which the eye's lens changes shape to focus images of near or far objects onto the retina.

Retina

The light-sensitive back inner surface of the eye, containing receptor rods and cones plus layers of neurons that begin the processing of visual information.

Fovea

The central focal point in the retina around which the eye's cones cluster.

Optic Nerve

The nerve that carries neural impulses from the eye to the brain.

Blind Spot

The point at which the optic nerve leaves the eye, creating an area where no receptor cells are located.

Rods

Retinal receptors that detect black, white, and gray, and are sensitive to movement; necessary for peripheral and twilight vision when cones do not respond.

Cones

Retinal receptors concentrated near the center of the retina that function in daylight or well-lit conditions, detecting fine detail and giving rise to color sensations.

Young-Helmholtz Trichromatic Theory

The theory that the retina contains three different types of color receptors—one most sensitive to red, one to green, and one to blue—which, when stimulated in combination, can produce the perception of any color.

Opponent-Process Theory

The theory that opposing retinal processes enable color vision; for example, some cells are stimulated by green and inhibited by red, while others are stimulated by red and inhibited by green.

Feature Detectors

Nerve cells in the brain's visual cortex that respond to specific features of a stimulus, such as shape, angle, or movement.

Nearsightedness (Myopia)

A visual condition where the lens focuses the image on a point in front of the retina, resulting in near objects being seen clearly while distant objects are blurry.

Farsightedness (Hyperopia)

A visual condition where distant objects are seen better than near objects because the lens focuses the image on a point behind the retina.

Prosopagnosia

A condition characterized by the inability to recognize faces, which can be inherited or acquired through a stroke or brain injury.

Blindsight

The ability to respond to visual information or visual stimuli without consciously seeing or experiencing it, often occurring after damage to the primary visual cortex.

Frequency

The number of complete wavelengths that pass a point in a given time (such as per second).

Pitch

A tone's experienced highness or lowness, which depends on the frequency of the sound wave.

Middle Ear

The chamber between the eardrum and cochlea containing three tiny bones that concentrate vibrations of the eardrum onto the cochlea's oval window.

Ossicles

Three tiny bones in the middle ear—the malleus (hammer), incus (anvil), and stapes (stirrup)—that amplify vibrations from the eardrum and transfer them to the inner ear.

Cochlea

A coiled, bony, fluid-filled tube in the inner ear through which sound waves travel to trigger nerve impulses.

Inner Ear

The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.

Sensorineural Hearing Loss

The most common form of hearing loss, caused by damage to the cochlea's receptor cells or the auditory nerve; also known as nerve deafness.

Conduction Hearing Loss

A less common form of hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.

Cochlear Implant

A device that converts sounds into electrical signals and stimulates the auditory nerve through electrodes threaded into the cochlea.

Place Theory

The hearing theory linking the pitch we hear to the place where the cochlea's membrane is stimulated, explaining how we hear high-pitched sounds.

Frequency Theory

The hearing theory stating that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, enabling the brain to read its pitch.

Volley Theory

The theory that neural cells alternate firing in rapid succession to achieve a combined frequency above $1000$ waves per second, explaining how we sense low pitches.

Pinna

The visible part of the outer ear that collects sound waves from the environment and funnels them into the ear canal.

Ear Canal

The tube (auditory canal) that channels and amplifies sound waves traveling from the pinna to the eardrum.

Eardrum

A thin, flexible membrane that vibrates when sound waves strike it, marking the transition from the outer ear to the middle ear.

Eustachian Tube

A canal connecting the middle ear to the throat that equalizes air pressure on both sides of the eardrum.

Auditory Nerve

The nerve that carries electrical signals generated by hair cells in the cochlea to the brain to be interpreted as sound.

Gate-Control Theory

The theory that the spinal cord contains a neurological gate that blocks pain signals or allows them to pass on to the brain.

Phantom-Limb Syndrome

A phenomenon where an individual experiences pain or sensations in an amputated or nonexistent limb because the brain misinterprets and amplifies central nervous system activity.

Gustation

The chemical sense of taste, which detects molecules rather than wavelengths of energy.

Oleogustus

A newer term denoting the taste category for fat, which plays an important role in food preferences.

Supertasters

Individuals who possess more taste buds than average, rendering them highly sensitive to specific flavors.

Olfaction

The chemical sense of smell, whose neurons bypass the thalamus and project directly to areas in the limbic system and olfactory cortex.

Proprioceptors

Position and motion sensors located in muscles, tendons, and joints throughout the body that provide continuous feedback to the brain.

Kinesthesis

The movement sense that keeps an individual aware of the position and movement of their individual body parts.

Vestibular Sense

The balance sense monitoring head and body position and movement, regulated by fluid-filled semicircular canals and crystal-filled vestibular sacs in the inner ear.

Embodied Cognition

The influence of bodily sensations, gestures, and other physical states on cognitive preferences and judgments.

Parallel Processing

The processing of multiple aspects of a stimulus or problem simultaneously.

Sequential Processing

The processing of one aspect of a stimulus or problem at a time, generally used for new information or difficult problems.

Circadian Rhythm

Our internal biological clock consisting of regular bodily rhythms (such as wakefulness and temperature) that occur on a $24$-hour cycle.

Alpha Waves

The relatively slow brain waves characteristic of a relaxed, awake state.

REM Sleep

Rapid eye movement sleep; a recurring sleep stage marked by vivid dreams and paradoxical muscle relaxation alongside active internal body systems.

NREM Sleep

Non-rapid eye movement sleep, encompassing all stages of sleep except for REM sleep.

Hypnagogic Sensations

Bizarre sensory experiences, such as jerking or feeling of falling or floating weightlessly, occurring while transitioning into sleep.

Delta Waves

The large, slow brain waves associated with deep sleep.

Suprachiasmatic Nucleus (SCN)

A pair of cell clusters in the hypothalamus that controls circadian rhythms by adjusting melatonin production in response to light.

Insomnia

A sleep disorder characterized by recurring problems in falling or staying asleep.

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks, in which the affected individual may lapse directly into REM sleep for about $5$ minutes.

Sleep Apnea

A sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings.

REM Sleep Behavior Disorder

A sleep disorder in which normal REM paralysis does not occur, leading to vocalizations or physical behaviors like kicking or punching to act out dreams.

REM Rebound

The tendency for REM sleep duration to increase following periods of REM sleep deprivation.

Activation-Synthesis Theory

The dream theory proposing that REM sleep triggers random neural activity that evokes visual memories, which the sleeping brain synthesizes into stories.

Ultradian Rhythm

Biological cycles that occur more than once a day, such as the cycle through the various stages of sleep.

Infradian Rhythm

Biological cycles that occur once a month or once a season, such as hibernation.

NREM Stage 3

The deepest non-rapid eye movement stage of sleep, lasting about $30$ minutes, characterized by large, slow delta waves and physical replenishment.

NREM Stage 2

A stage of light non-rapid eye movement sleep lasting approximately $20$ minutes during which brain activity slows down.

Sensation

The process by which sensory receptors and the nervous system receive and represent stimulus energies from our environment.

Perception

The process by which the brain organizes and interprets sensory information, enabling us to recognize objects and events as meaningful.

Bottom-Up Processing

Information processing that starts at sensory receptors and works up to higher brain levels of sensory integration.

Top-Down Processing

Information processing guided by higher-level mental processes, constructing perceptions based on prior experience and expectations.

Transduction

The conversion of one form of energy into another; in sensation, transforming physical energies into neural impulses the brain can interpret.

Psychophysics

The study of relationships between the physical characteristics of stimuli (such as their intensity) and our psychological experience of them.

Absolute Threshold

The minimum stimulus energy needed to detect a particular stimulus $50\%$ of the time.

Signal Detection Theory

A theory predicting how and when we detect the presence of a faint stimulus amid background noise, assuming detection depends on experience, expectation, motivation, and alertness.

Subliminal

Stimuli falling below one's absolute threshold for conscious awareness.

Priming

The often unconscious activation of particular associations that predisposes an individual's perception, memory, or response.

Sensory Adaptation

Diminished sensitivity that occurs as a consequence of constant, unchanging sensory stimulation.

Weber's Law

The principle stating that two stimuli must differ by a constant minimum percentage (rather than a constant amount) to be perceived as different.

Difference Threshold

The minimum difference between two stimuli required for detection $50\%$ of the time; experienced as a just noticeable difference (jnd).