Untitled Flashcards Set

Sensation

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

Transduction

The conversion of one form of energy into another, specifically in sensory systems, the transformation of stimulus energies into neural impulses.

Absolute threshold

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

Just-noticeable difference (JND)

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

Sensory adaptation

A decrease in sensitivity to a constant level of stimulation.

Weber’s law

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

Sensory interaction

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

Synesthesia

A condition in which stimulation of one sensory modality leads to automatic, involuntary experiences in a second sensory modality.

Retina

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

Blind spot

The point at which the optic nerve leaves the eye, resulting in an area of no vision.

Visual nerve

The nerve that carries visual information from the retina to the brain.

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 near or far objects on the retina.

Nearsightedness

A condition in which close objects appear clearly, but far ones do not, due to the shape of the eye.

Farsightedness

A condition in which far away objects are seen clearly, but close ones do not, due to the shape of the eye.

Photoreceptors

Cells in the retina that convert light energy into neural signals.

Rods

Photoreceptor cells in the retina that are sensitive to low light levels and allow for night vision.

Cones

Photoreceptor cells in the retina that are responsible for color vision and function best in bright light.

Trichromatic theory

The theory that the retina contains three types of color receptors—one sensitive to red, one to green, and one to blue.

Opponent-process theory

The theory that opposing retinal processes enable color vision; for example, red-green, blue-yellow.

Afterimages

Visual images that persist after the removal of a stimulus.

Ganglion cells

Retinal neurons that receive inputs from photoreceptors and transmit the visual information to the brain.

Dichromatism

A type of color blindness where a person has only two types of cone photoreceptors.

Monochromatism

A type of color blindness where a person has only one type of cone photoreceptor.

Prosopagnosia

A neurological condition characterized by the inability to recognize faces.

Blindsight

A condition in which a person can respond to visual stimuli without consciously perceiving them.

Wavelength

The distance between the peaks of a wave, which determines the color of light.

Pitch

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

Amplitude

The height of a wave, which determines the loudness of sound.

Loudness

The perceptual dimension of sound that corresponds to the amplitude of the sound wave.

Pitch perception

The ability to perceive the frequency of a sound wave.

Place theory

The theory that links the pitch we hear with the place where the cochlea's membrane is stimulated.

Volley theory

The theory stating that groups of neurons can fire in rapid succession to create complex sounds.

Frequency theory

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

Sound localization

The ability to determine the source of a sound in space.

Conduction deafness

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

Sensorineural deafness

Hearing loss caused by damage to the cochlea's receptor cells or the auditory nerves.

Olfactory system

The sensory system responsible for the sense of smell.

Thalamus

The brain's sensory switchboard that routes sensory information to the appropriate areas.

Pheromones

Chemicals produced by one species that influence the behavior of other members of the same species.

Gustation

The sense of taste, which is activated by chemical substances in food.

Taste receptors

Cells that are responsible for the sense of taste.

Supertasters

Individuals with heightened sensitivity to taste, often having more taste buds than average.

Medium tasters

Individuals with a regular number of taste buds and sensitivity to taste stimuli.

Nontasters

Individuals with fewer taste buds, resulting in a decreased sensitivity to taste.

Warm/cold receptors

Sensory receptors that respond to changes in temperature.

Gate control theory

The theory that suggests pain is controlled by a gate mechanism in the spinal cord.

Phantom limb

Sensation that an amputated or missing limb is still attached and functioning.

Vestibular sense

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

Semicircular canals

Structures in the inner ear involved in maintaining balance.

Kinesthesis

The body's ability to sense its position and movement in space, allowing for coordination and balance.