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 of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
bottom-up processing
analysis 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.
selective attention
the focusing of conscious awareness on a particular stimulus.
cocktail party effect
explains one's ability to focus one's attention on one particular sound (an auditory stimulus) while simultaneously filtering out others.
inattentional blindness
failing to see visible objects when our attention is directed elsewhere.
transduction
conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our 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.
difference threshold
the minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference (or jnd).
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).
priming
the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response.
persuasion
Strategies or methods used to influence someone's attitudes, beliefs, behaviors, or decisions.
sensory adaptation
diminished sensitivity as a consequence of constant stimulation.