Chapter 4: Sensation and Perception Flashcards
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
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 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 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
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 adaption
diminished sensitivity as a consequence of constant stimulation
perceptual set
a mental predisposition to perceive one 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
wavelength
the distance from the peak of one light or sound wave to the peak of the next
intensity
the amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness. Intensity is determined by the wave’s amplitude (height)
cornea
the eye’s clear, protective outer layer, covering the pupil and iris
pupil
the adjustable opening in the center of the eye through which light enters
iris
a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening
lens
the transparent structure behind the pupil that changes shape to help focus images on the retina