Sensation and Perception – Chapter 3 (Hockenbury & Nolan, 10th ed.)

Vocabulary flashcards covering major terms and concepts from the chapter on sensation and perception, including visual, auditory, chemical, body senses, perceptual organization, depth cues, pain, and illusions.

Sensation

The process of detecting physical energy (light, sound, heat, pressure, etc.) and converting it into neural signals.

Perception

The process of integrating, organizing, and interpreting sensory information to form meaningful representations.

Sensory Receptor

Specialized cell in a sense organ that responds to a particular form of sensory stimulation.

Transduction

Conversion of physical energy into a coded neural signal that the nervous system can process.

Absolute Threshold

The minimum intensity of a stimulus that can be detected 50 % of the time.

Difference Threshold (JND)

The smallest change in stimulation that can be detected; ‘just noticeable difference.’

Weber’s Law

Principle stating the size of the JND is a constant proportion of the original stimulus intensity.

Sensory Adaptation

A gradual decline in sensitivity to a constant stimulus over time.

Rods

Long, thin photoreceptors in the retina highly sensitive to light but not to color; dominate in low-light vision.

Cones

Short, thick photoreceptors in the retina that detect color and enable visual acuity; concentrated in the fovea.

Fovea

Small central area of the retina composed entirely of cones where vision is sharpest.

Blind Spot

Point where the optic nerve exits the eye; contains no photoreceptors, creating a gap in the visual field.

Accommodation (Vision)

Process by which the eye’s lens changes shape to focus light on the retina.

Optic Chiasm

Point where optic nerve fibers partially cross, sending visual information to opposite sides of the brain.

Ventral Stream

The ‘what’ visual pathway that processes object identity in the temporal lobe.

Dorsal Stream

The ‘where’ visual pathway that processes spatial location and movement in the parietal lobe.

Synesthesia

A condition in which stimulation of one sense involuntarily triggers the experience of another (e.g., numbers perceived as colors).

Hue

Aspect of color determined by the wavelength of light.

Saturation

Purity of a light wave; the extent to which a color is diluted by white light.

Brightness

Perceived intensity of light; related to the amplitude of the light wave.

Trichromatic Theory

Theory that color sensation results from activity in three cone types sensitive to red, green, or blue wavelengths.

Opponent-Process Theory

Theory that color perception is controlled by opposing retinal processes (red–green, blue–yellow, black–white).

Color Blindness

Deficiency in one or more cone types, most commonly affecting red–green discrimination.

Sound Wave

Physical stimulus for audition; a series of pressure changes traveling through a medium such as air.

Amplitude (Sound)

Height of a sound wave; determines loudness, measured in decibels (dB).

Decibel (dB)

Unit that measures the intensity or loudness of sound.

Frequency (Sound)

Number of sound waves per second; determines pitch and is measured in hertz (Hz).

Pitch

Perceived highness or lowness of a sound based on its frequency.

Timbre

Distinctive quality or complexity of a sound that allows differentiation of sources producing the same pitch.

Cochlea

Fluid-filled, spiral structure in the inner ear where sound waves are transduced into neural impulses.

Basilar Membrane

Structure inside the cochlea whose movement bends hair cells to create auditory signals.

Frequency Theory

Proposes that the basilar membrane vibrates at the same frequency as the sound wave, explaining low-pitch perception.

Volley Principle

Idea that groups of neurons fire in alternation to code frequencies higher than a single neuron’s firing limit.

Place Theory

Suggests different sound frequencies produce maximal vibration at specific places along the basilar membrane, explaining high-pitch perception.

Olfaction

The chemical sense of smell, mediated by receptors sending signals to the olfactory bulb.

Gustation

The chemical sense of taste detected by taste buds for sweet, sour, salty, bitter, and umami.

Taste Bud

Cluster of about 50 taste receptors located in papillae on the tongue.

Proprioception

Sense of body position and movement provided by receptors in muscles and joints.

Vestibular Sense

Sense of balance and spatial orientation arising from semicircular canals and vestibular sacs in the inner ear.

Nociceptor

Free nerve ending that responds to tissue damage, producing the sensation of pain.

Fast Pain System

Pathway that conveys sharp, localized pain via large, myelinated fibers to the somatosensory cortex.

Slow Pain System

Pathway that conveys dull, throbbing pain via smaller, unmyelinated fibers to limbic structures.

Gate-Control Theory

Model proposing that pain signals can be modulated by ‘gates’ in the spinal cord influenced by psychological factors.

Phantom Limb Pain

Painful sensation perceived in a limb that has been amputated.

Bottom-Up Processing

Perceptual analysis that begins with sensory receptors and builds up to a complete perception.

Top-Down Processing

Perception shaped by prior knowledge, expectations, and cognitive processes.

Gestalt Psychology

View that we perceive whole forms (gestalts) rather than separate sensations; emphasizes innate rules of organization.

Figure–Ground Relationship

Tendency to automatically separate visual scenes into a main object (figure) and background (ground).

Similarity (Gestalt)

Grouping principle where similar elements are perceived as belonging together.

Proximity (Gestalt)

Grouping principle where objects close to each other are perceived as a group.

Continuity (Gestalt)

Tendency to perceive smooth, continuous patterns rather than discontinuous ones.

Closure (Gestalt)

Tendency to fill in gaps to perceive a complete, whole object.

Depth Perception

Ability to perceive distance and three-dimensional relationships using visual cues.

Monocular Cue

Depth cue, such as relative size or linear perspective, that requires only one eye.

Relative Size

Monocular cue where smaller retinal images are perceived as farther away.

Overlap (Interposition)

Monocular cue where an object blocking another is perceived as closer.

Aerial Perspective

Monocular cue where hazy objects are seen as farther away due to atmospheric scattering.

Texture Gradient

Monocular cue where coarse, detailed textures appear closer than smooth, indistinct textures.

Linear Perspective

Monocular cue where parallel lines appear to converge with distance.

Motion Parallax

Monocular cue where closer objects seem to move faster across the visual field than distant ones.

Binocular Cue

Depth cue that depends on information from both eyes, e.g., convergence and disparity.

Convergence

Degree of inward turning of the eyes used as a cue for distance; more rotation indicates closer objects.

Binocular Disparity

Difference in retinal images of the two eyes; greater disparity signals closer distance.

Perceptual Constancy

Tendency to perceive objects as stable despite changes in sensory input.

Size Constancy

Perceiving an object’s size as constant despite changes in its retinal image.

Shape Constancy

Perceiving a familiar object’s shape as constant even when its orientation changes.

Perceptual Illusion

Misinterpretation of a true sensory stimulus, revealing perceptual principles.

Müller-Lyer Illusion

Visual illusion in which identical line lengths appear different due to arrowhead orientation.

Moon Illusion

Apparent enlargement of the moon near the horizon compared to overhead, due to distance cues.

Carpentered-World Hypothesis

Idea that people in industrialized settings are more susceptible to certain illusions because of experience with right-angled environments.

Perceptual Set

Readiness to perceive stimuli in a particular way based on expectations or context.

Extrasensory Perception (ESP)

Claimed perception of information without sensory input; includes telepathy, clairvoyance, precognition, psychokinesis.

Distraction (Pain Strategy)

Cognitive technique of focusing attention elsewhere to reduce perceived pain.

Umami

Fifth basic taste quality associated with savory flavors and glutamate.

Hair Cell (Ear)

Sensory receptor on the basilar membrane that converts fluid movement into auditory nerve impulses.

Oval Window

Membrane on the cochlea driven by the stirrup; sets cochlear fluid in motion.

Volley (Auditory) Principle

Mechanism by which clusters of neurons alternate firing to encode high frequencies.