Key Terms Ch3 Essay

Submitted By jaywiggle
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Key Terms
Chapter 3
Sensation: the process through which the sense pick up visual, auditory and other sensory stimuli and transmit them to the brain.
Perception: the process by which the brain activity organizes and interprets sensory information.
Absolute threshold: the minimum amount of sensory stimulation that can be detected 50% of the time.
Difference threshold: a measure of the smallest increase or decrease in a physical stimulation that is required to produce a difference in sensation that is noticeable 50% of the time.
JND: the smallest change in sensation that a person is able to detect 50% of the time.
Weber’s law: the law stating that the just noticeable difference (JND) for all the senses depend on a proportion or percentage of change in a stimulus rather than on a fixed amount of change.
Sensory reception: highly specialized cells in the sense organs that detect and respond to one type of sensory.
Transduction: the process through which sensory receptors convert the sensory stimulation into neural impulses.
Sensory adaption: the process in which sensory receptors grow accustomed to constant, unchanging levels of stimuli over time.
Visible spectrum: the narrow band of light waves that are visible to the human eye.
Wavelength: a measure of the distance from the peck of a light wave to the peck of the next.
Lens: the transparent disk shaped structure behind the iris and the pupil that changes shape as it focuses on objects at varying distances.
Accommodations: the flattening and bulging action of the lens as it focuses images of the object on the retina.
Retina: the layer of tissue that is located on the inner surface of the eyeball and contains the sensory receptors of vision.
Rods: the light sensitive receptor cells in the retina that look like slender cylinders and allow the eye to respond to as few as five protons.
Cones: the light sensitive receptor cells in the retina that enable humans to see color and fine detail in adequate light do not function in very dim light.
Fovea: a small area at the center of the retina that provides the clearest and sharpest vision because it has the largest concentration of cones.
Blind spot: the point in each retina where there are no rods or cones because the cable of ganglion cell is extended through the retinal wall.
Optic nerve: the nerve that carries visual information from each retina to both sides of the brain.

Primary visual cortex- the part of the brain in which visual information is processed.
Feature detectors- neurons in the brain that respond only to specific visual patterns
Hue- the dimension of light that refers to the specific color received
Saturation- the purity of a color, or the degree to which the light waves producing it are of the same wavelength
Brightness- the intensity of light energy perceived as color; based on amplitude of the light wave trichromatic theory- the theory of color vision suggesting that three types of cones in the retina each make a maximal chemical response to one of three colors- blue, green, or red
Opponent-process theory- the theory of color vision suggesting that three kinds of cells respond by increasing or decreasing their rate of firing when different colors are present
Afterimage- a visual sensation that remains after a stimulus is withdrawn
Color blindness- the inability to distinguish certain colors from one another
Frequency- the number of cycles completed by a sound wave in one second, determining the pitch of the sound; expressed in the unit called the hertz
Amplitude- the measure of the loudness of a sound; expressed in the unit called the decibel
Decibel- a unit of measurement for the loudness of sounds
Timbre- the distinctive quality of a sound that distinguishes it from other sounds of the same pitch and loudness
Cochlea- the fluid-filled, snail-shaped bony chamber in the inner ear that contains the basilar membrane and its hair cells
Hair cells- sensory receptors for hearing that are attached to the basilar…