Sensation and Perception Vocabulary

Vocabulary terms and definitions covering key concepts of sensation and perception.

Absolute threshold

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

Binocular disparity

A depth cue caused by the slight difference between the images seen by your two eyes.

Bottom-up processing

Perception that starts with sensory information and builds toward understanding.

Cocktail party effect

The ability to focus on one conversation while filtering out other conversations, but still notice important information like your name.

Cones

Photoreceptors in the retina that detect color and work best in bright light.

Convergence

A binocular depth cue based on how much the eyes turn inward when focusing on a nearby object.

Figure-ground relationships

The tendency to separate a visual field into a main object (figure) and its background (ground).

Gate-control theory

The idea that the spinal cord contains a “gate” that can block or allow pain signals to reach the brain.

Gustation

The sense of taste.

Habituation

A decrease in response to a repeated, harmless stimulus.

Just noticeable difference (JND)

The minimum difference between two stimuli that a person can detect $50\%$ of the time.

Kinesthetic senses

Senses that provide information about the position and movement of your body and limbs.

Fovea

The small area in the retina containing many cones; it provides the sharpest vision.

Olfaction

The sense of smell.

Opponent-process theory

The theory that color vision is based on opposing pairs: red-green, blue-yellow, and black-white.

Retina

The light-sensitive layer at the back of the eye containing rods and cones.

Rods

Photoreceptors that detect dim light and movement but do not detect color well.

Transduction

The process of converting sensory energy into neural signals that the brain can understand.

Sensory adaptation

A decrease in sensitivity to a constant, unchanging stimulus.

Vestibular senses

Senses that provide information about balance, body position, and movement.

Weber’s Law

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

Synesthesia

A condition in which stimulation of one sense automatically triggers another sense, such as seeing colors when hearing music.

Perceptual set

A mental tendency to perceive something in a particular way based on expectations, experiences, or context.

Perceptual expectancy

The tendency to perceive something based on what you expect to perceive.

Frequency theory

The theory that the rate of neural impulses in the auditory nerve matches the frequency of a sound's pitch.

Place theory

The theory that different frequencies of sound activate different locations on the basilar membrane in the cochlea.