Pain: Physiological Mechanisms

In the late 1960s, John F. Hahn, a sensory gener-alist in the tradition of Henri Piéron and Frank Geldard, taught that pain is not only a sensation in search of a stimulus, but in search of a receptor as well. In the years since those discussions, understanding of the mapping of stimulus on receptor to sensation has not changed much. There is no question that pain is a dramatic and attention-grabbing event when it occurs—when skin temperature is too high or too low, when we taste or touch chemicals, such as capsaicin (from chilies) or when we stub our toe—and then again a few seconds later, but perceived differently—duller and less sharp. But one could argue that the most interesting aspect of pain is when ...