Sensations+PowerPoint

Sensation

A process by which our sensory receptors and nervous system receive and represent stimulus energy.

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Bottom-Up Processing

Analysis that begins with the sense receptors and works up to the brain’s integration of sensory information.

Top-Down Processing

Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.

Transduction

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

Psychophysics

The study of the relationship between physical characteristics of stimuli and our psychological experience of them.

Absolute Threshold

The minimum stimulation needed to detect a particular stimulus 50% of the time.

Difference Threshold

The minimum difference between two stimuli required for detection 50% of the time.

Weber’s Law

To perceive as different, two stimuli must differ by a constant minimum percentage.

Subliminal

Stimuli that are below one's absolute threshold for conscious awareness.

Sensory Adaptation

Diminished sensitivity as a consequence of constant stimulation.

Audition

The sense of hearing.

Frequency

The number of complete wavelengths that pass a point in a given time.

Pitch

A tone's highness or lowness; it depends on frequency.

Place Theory

Links the pitch we hear with the place where the cochlea's membrane is stimulated.

Frequency Theory

The rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone.

Conduction Hearing Loss

Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.

Sensorineural Hearing Loss

Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerve.

Kinesthesis

The system for sensing the position and movement of individual body parts.

Vestibular Sense

The sense of body movement and position, including the sense of balance.

Taste Sensations

Sweet, sour, salty, bitter, umami.

Sensory Interaction

The principle that one sense may influence another.

Retronasal Olfaction

The perception of odors emanating from the oral cavity during eating and drinking.

Olfactory Nerve

The nerve that carries smell impulses from the nose to the brain.

Visual Acuity

The sharpness of vision.

Rods

Receptors in the peripheral retina that detect black, white, and gray, and are used for twilight or low-light conditions.

Cones

Receptors near the center of the retina that are responsible for fine detail and color vision in well-lit conditions.

Phototransduction

The process by which light is converted into electrical signals in the retina.

Pupil

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

Lens

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

Retina

The light-sensitive inner surface of the eye, containing receptor rods and cones.

Fovea

The central focal point in the retina, where cones are densely packed and vision is sharpest.

Blind Spot

The point at which the optic nerve leaves the eye and no receptor cells are located there.

Afterimage

A visual sensation that remains after the original stimulus has been removed.

Color Vision

The ability to perceive differences in wavelengths of light, which correspond to different colors.

Trichromatic Theory

Theory that the retina contains three types of color receptors (red, green, blue) which can create any color.

Opponent-Process Theory

Theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision.

Gestalt Principles

Rules that describe how we organize visual elements into groups or unified wholes.

Depth Perception

The ability to perceive distance and three-dimensionality based on visual cues.

Binocular Cues

Depth cues that require the use of both eyes, such as retinal disparity and convergence.

Monocular Cues

Depth cues that can be perceived with one eye, such as relative size and interposition.

Perceptual Constancy

The ability to perceive objects as unchanging even as illumination and retinal images change.

Size Constancy

The perception of an object as the same size regardless of its distance from the viewer.

Shape Constancy

The perception of an object as having a constant shape, even when viewed from different angles.