Psychology Modules 16-17

Sensation

The process by which our sensory receptors and nervous system perceive 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

inattentional blindness

failing to see visible objects when our attention is directed elsewhere.

change blindness

failing to notice changes in the environment; a form of inattentional blindness

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 out 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)

Priming

the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response

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

Perceptual set

a mental predisposition to perceive on thing and not another

Extrasensory perception (ESP)

the controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition

parapsychology

the study of paranormal phenomena, including ESP and psychokinesis