Sensation Flashcards
The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.
Sensation
The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
Perception
Analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information.
Bottom-up processing
Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.
Top-down processing
the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them
it can concern how sensitive we are to changing stimulation
Psychophysics
the minimum stimulation needed to detect a particular stimulus 50% of the time; illustrated by our awareness of faint stimuli such as seeing a candle flame atop another mountain 30 miles away or smelling a single drop of perfume in a three-room apartment
Absolute threshold
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 level of fatigue
Signal detection theory
below one’s absolute threshold for conscious awareness
Subliminal
the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response
Priming
the minimum difference between two stimuli required for detection 50% of the time; we experience this as a just noticeable difference
Difference threshold
the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount)
Weber’s law
diminished sensitivity as a consequence of constant stimulation
Sensory Adaptation
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 brains can interpret
transduction
the distance from the peak of one light or sound wave to the peak of the next; electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission
wavelength
the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, etc.
hue
the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave’s amplitude
intensity
the adjustable opening in the center of the eye through which light enters
pupil
a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening
iris
the transparent structure behind the pupil that changes shape to help focus images on the retina
lens
the process by which the eye’s lens changes shape to focus near or far objects on the retina
accommodation
the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information
retina