VOCAB

Sensation

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

Sensory receptors

Sensory nerve endings that respond to stimuli.

Perception

The process by which our brain organizes and interprets sensory information, enabling us to recognize objects and events as meaningful.

Bottom-up processing

Information processing that begins with the sensory 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

Conversion of one form of energy into another; in sensation, the transforming of physical energy into neural impulses the brain can interpret.

Psychophysics

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

Absolute threshold

The minimum stimulus energy needed to detect a particular stimulus 50 percent of the time.

Signal detection theory

A theory predicting how and when we detect the presence of a faint stimulus amid background stimulation; assumes there is no single absolute threshold.

Subliminal

Below one's absolute threshold for conscious awareness.

Weber's Law

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

Sensory adaptation

Diminished sensitivity as a consequence of constant stimulation.