Unit 1 Sensation and Perception Vocab

Sensation

The process of detecting physical energy from the environment and converting it into neural signals.

Perception

The organization and interpretation of sensory information into meaningful experiences.

Transduction

The conversion of physical stimulus energy into neural impulses.

Absolute threshold

The minimum stimulation detected 50 percent of the time.

JND

The smallest difference between two stimuli detected 50 percent of the time.

Weber's law

The principle that a noticeable difference is a constant proportion of the original stimulus.

Sensory adaptation

Reduced sensitivity after constant, unchanging stimulation.

Sensory interaction

The influence of one sensory system on another.

Synesthesia

A condition in which stimulation of one sense automatically produces an experience in another.

Retina

The light-sensitive inner surface at the back of the eye.

Lens

The transparent eye structure that focuses light onto the retina.

Accommodation

The lens changing shape to focus near or far objects on the retina.

Nearsightedness

A focusing condition in which nearby objects are clearer than distant ones.

Farsightedness

A focusing condition in which distant objects are clearer than nearby ones.

Rod

A retinal receptor sensitive to dim light, movement, and black-and-white vision.

Cone

A retinal receptor concentrated near the fovea and specialized for color and detail.

Fovea

The retinal area of sharpest vision, containing a high concentration of cones.

Blind spot

The retinal location where the optic nerve leaves the eye and no receptors are present.

Trichromatic theory

The theory that color vision begins with three cone types most sensitive to red, green, or blue wavelengths.

Opponent process theory

The theory that color is processed in opposing channels such as red-green and blue-yellow.

Afterimage

A visual image that persists after a stimulus is removed, often in opponent colors.

Color vision deficiency

Reduced ability to distinguish certain colors because of cone or ganglion-cell differences.

Dichromatism

Color vision based on two functioning cone systems rather than three.

Monochromatism

A rare condition involving little or no functional color vision.

Prosopagnosia

Face blindness caused by impaired facial-recognition processing.

Blindsight

The ability to respond to visual information without conscious visual awareness.

Wavelength

The distance between wave peaks; in sound, it is related to pitch.

Amplitude

Wave height; in sound, it is related to perceived loudness.

Pitch

The perceived highness or lowness of a sound.

Loudness

The perceived intensity of a sound.

Place theory

The theory that pitch depends on where the basilar membrane vibrates most.

Frequency theory

The theory that pitch is represented by the rate at which auditory neurons fire.

Volley theory

The theory that groups of auditory neurons alternate firing to represent higher frequencies.

Sound localization

Determining where a sound originates by comparing input to the two ears.

Conduction hearing loss

Hearing loss caused by difficulty transmitting sound through the outer or middle ear.

Sensorineural hearing loss

Hearing loss caused by damage to inner-ear hair cells, the auditory nerve, or brain pathways.

Olfaction

The sense of smell.

Pheromone

A chemical signal released by an organism that may affect members of the same species.

Gustation

The sense of taste.

Umami

A savory taste associated with amino acids such as glutamate.

Oleogustus

A proposed basic taste associated with fatty acids.

Supertaster

A person with unusually high taste sensitivity, often linked to more taste receptors.

Nontaster

A person with relatively low taste sensitivity.

Gate control theory

The theory that spinal-cord mechanisms can increase or decrease pain signals reaching the brain.

Phantom limb sensation

Sensation or pain perceived in a limb that has been amputated.

Vestibular sense

The sense of balance and head movement, supported mainly by the inner ear and brain.

Semicircular canals

Fluid-filled inner-ear structures that detect rotational head movement.

Kinesthesis

The sense of the position and movement of one's body parts.