PS101 Lecture 6: PS 101 Week 6 Ch
Document Summary
Threshold: dividing point between energy levels that do and do not have a detectable energy. Absolute threshold: minimum amount of stimulation that an organism can detect. This defines the boundaries of an organism"s sensory capabilities. A just noticeable difference (jnd) is the smallest difference in the amount of stimulation that a specific sense can detect. Weber"s law states that the size of a jnd is a constant proportion of the size of the initial stimulus. You should be able to detect the difference from 300-grams and 310-grams. But for a 900-gram weight, you wouldn"t feel the difference between 900-grams and 910-grams. Fechner"s law: the magnitude of a sensory experience is proportional to the number of jnds that the stimulus causing the experience is above the absolute threshold. This means that constant increments in stimulus intensity produce smaller increases in perceived magnitude of sensation. Example: dark room, 1 light bulb versus dark room 3 light bulbs, not that much different.
