3 Sensation and Perception Flashcards
Sensation
the experience of sensory stimulation
Perception
the process of creating meaningful patterns from raw sensory information
Receptor cell
a special cell that responds to a particular type of energy
Absolute threshold
the least amount of energy that can be detected 50% of the time
Adaptation
an adjustment of the senses to the level of stimulation they are receiving
Difference threshold (just noticeable difference)
the smallest change in stimulation that can be detected 50% of the time
Weber’s law
the principle that the jnd for any given sense is a constant fraction or proportion of the stimulation being judged
Cornea
the transparent protective coating over the front part of the eye
Pupil
a small opening in the iris through which light enters the eye
Iris
the colored part of the eye
Lens
the transparent part of the eye inside the pupil that focuses light onto the retina
Retina
the lining of the eye containing receptor cells that are sensitive to light
Blind spot
the place on the retina where the axons of all the ganglion cells leave the eye and where there are no receptors
Fovea
the area of the retina that is the center of the visual field
Light
the small segment of the electromagnetic spectrum to which our eyes are sensitive
Rods
receptor cells in the responsible for night vision and perception of brightness
Cones
receptor cells in the retina responsible for color vision
Bipolar cells
Neurons that have only one axon and one dendrite; in the eye, these neurons connect the receptors on the retina to the ganglion cells
Visual acuity
the ability to distinguish fine details visually
Dark adaptation
increased sensitivity of rods and cones in darkness
Light adaptation
decreased sensitivity of rods and cones in bright light
Afterimage
sense experience that occurs after a visual stimulus has been removed
Ganglion cells
neurons that connect the bipolar cells in the eye to the brain
Optic nerve
the bundle of axons of ganglion cells that carries the messages from each eye to the brain
Optic chiasm
the point near the base of the brain where some fibers in the optic nerve from each eye cross to the other side of the brain
Feature detectors
specialized brain cells that only respond to particular elements in the visual field such as movement or lines of specific orientation
Hue
the aspect of color that corresponds to names such as red, green, and blue
Saturation
the vividness or richness of a hue
Brightness
the nearness of a color to white as opposed to black
Additive color mixing
the process of mixing lights of different wavelengths to create new hues
Subtractive color mixing
the process of mixing pigments, each of which absorbs some wavelengths of light and reflects others
Trichromatic theory
the theory of color vision that holds that all color perception derives from three different color receptors in the retina (usually red, green, and blue receptors)
Trichromats
people who have normal color vision
Color blindness
Partial or total inability to see hues
Dichromats
People who are blind to either red-green or yellow-blue