Pain tolerance and kinesthetic after-effect.

Abstract

In a recent series of papers, Petrie, Collins, and Solomon (1958, 1960) and Peuie (1960) argued that individual differences in pain tolerance (and in tolerance of sensory deprivation) are part of a more general perceptual characteristic of or sensory inputs. Augmenting and reducing were measured by the kinesthetic after-effect apparatus. This test, first described by Koehler and Dinnerstein (1947), involves matching the width of a standard bar which is felt with one hand with a region of a tapered bar which is explored with the other hand. Interpolated kinesthetic experience (satiation) of the former hand on a bar larger or smaller than the standard produces a contrast effect. The standard will be subsequently underestimated or overestimated, respectively. The magnimde of the above constant errors has been shown to correlate with other variables of individual difference (Kline and Krech, 1952; Wertheimer, 1955). Petrie, Collins, and Solomon, however, claimed that pain tolerance is predicted by a direction of constant error which is independent of the width of the satiation bar employed in the interpolated experience. They report that, for some Ss, (an increasingly positive constant error) appears with both larger and smaller satiation bars. The same is reported for reducing. It was these constant errors which related to pain tolerance. The phenomenon of augmenting and reducing is described as being different from the traditional kinesthetic after-effect. Koehler and Dinnerstein, however, warned that such effects might appear if Ss always started their kinesthetic exploration from only one end of the tapered comparison bar. Starting from the narrow end, for example, would produce a rapid satiation of the hand employed, as if by a narrow satiation bar. This would produce an overestimation of the mid-region of the tapered bar, and an apparent underestimation of the standard. This effect cannot be avoided, but the errors can be balanced out by alternating ascending and descending trials, by starting from the wide and narrow ends of the tapered bar on alternate trials. The studies by Peuie, Collins, and Solomon employed only ascending uials (personal communication from Petrie). Augmenting and reducing may thus be, in one sense, an artifact of a failure to alternate ascending and descending uials. The present study aimed to discover if the correlation between pain 'The research was supported, in part, by Grant No. U-1140 from the Health Research Council of the City of New York.