Sensation and Perception

• 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).
• 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


  the 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
• cones


  retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions.
• amplitude


  Height of a wave

  Loudness

  The maximum distance the wave moves up or down from its rest position.