psychology vocabulary chapter 5-sensory adaptation

signal direction 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 and that detection depends partly on a persons experience, expectations, motivation, and level of fatigue

bottom-up processing

analysis that begins with the sensory receptors and works up to the brains integration of sensory information

Subliminal

below ones absolute threshold for conscious awareness

sensory adaptation

diminished sensitivity as a consequence of constant stimulation

top-down processing

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.

priming

the activation, often unconsciously of certain associations thus predisposing ones perception, memory, or response.

difference threshold

the minimum difference between two stimuli required for detection 50% of the time. We experience the difference threshold as a just noticeable difference.

absolute threshold

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

webers law

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

sensation

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

perception

the process of organizing and interpreting sensory information enabling us to recognize meaningful objects and events.

Psychophysics

the study of relationships between the physical characteristics of stimuli, such as their intensity and our psychological experience of them