Sensory Intensity Versus Hedonic Functions: Classical Psychophysical Approaches

ABSTRACT Studies of sensory intensity and hedonics (pleasantness and unpleasantness) of simple and complex stimuli show two quite different appearing functions. Type I functions show parallel increases of unpleasantness (or rarely pleasantness) with sensory intensity. Continua exhibiting Type I functions are often aversive such as sourness, noise annoyance, etc. Type II functions show maximum pleasantness value (optimum points) at an intermediate sensory level. Continua exhibiting Type II functions include acceptability of sugar and salt.