Chapter 6: Sensation and Perception Flashcards
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
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
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 stimulation 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
Priming
The activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response
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)
Sensory Adaptation
Diminished sensitivity as a consequence of constant stimulation
Perceptual Set
A mental predisposition to perceive one thing and not another
Wavelength
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
Hue
Dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth
Intensity
The amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave’s amplitude
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
Retina
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
Accommodation
The process by which the eye’s lens changes shape to focus near of far objects on the retina
Rods
Retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don’t respond
Cones
Retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations