Modules 17-19 (Lecture 6) 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, like rods and cones, taste buds, olfactory nerves, tough receptors, etc
Perception
The process by which our brain organizes and interprets 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 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 Thershold
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
A phenomenon where exposure to a stimulus influences how someone responds to a later stimulus, without their conscious awareness
Sensory Adapation
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 gamma rays to the long pulses of radio transmissions.
Hue
The dimension of the color determined by the wavelength of light; what we know was the color names blue, green, and etc;
Intensity
The amount of energy in a light wave or sound wave, which influences what we perceive as brightness what we perceive as brightness or loudness. Intensity is determined by the wave’s amplitude (height)
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 or far objects on the retina.
Rods
Retinal receptors that detect black, white, and gray, and are sensitive to movement. Rods are necessary for peripheral and twilight vision, when cones don’t respond.
Cones
Retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. Cones detect fine detail and give rise to color sensations.
Optic nerve
The nerve that carries neural impulses from the eye to the brain.
Blind Spot
The point at which the optic nerve leaves the eye, creating a “blind” spot because no recepetor cells are located there.
Fovea
The central focal point in the retina, around which the eye’s cones cluster.
