ABSTRACT
Psychophysical theory has two primary goals: to provide a sensory platform for inferring processes at the level of neurophysiology and to provide a judgment platform for understanding events at the level of perception. The enterprise is more successful in exploring the downward path to neurophysiology than it is explaining the upward path to perception. The reason for this is that—although it is possible to restrict the options in the laboratory so that only sensory mechanisms prevail—it is more difficult to extrapolate from the relatively impoverished conditions of the laboratory to field situations. The arrow of generalization is asymmetric, straighter toward sensation than toward perception.
