VOCAB

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

Sensory receptors- sensory nerve ending 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, such as sights, sounds, and smells, into neural impulses the brain can interpret.

Psychophysics- the study of relationships between the physical characteristics of stimuli, such as their Intensity, 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 (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness.

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 (rather than a constant amount).

Sensory adaptation- diminished sensitivity as a consequence of constant stimulation.