On Evaluating Autonomic and Verbal Indices of Negative Preception.

Negative preception (NP) has been defined as the attenuation of a noxious stimulus by a signal which precedes it. Explanatory theories to account for the NP phenomenon are available, but the concern of this paper is with the methodological and empirical basis for the existence of the NP phenomenon itself. It is argued that autonomic indices based on shock-elicited responding cannot provide unconfounded evidence for NP because of insurmountable methodological problems associated with response-interference and perceptual-disparity (or orienting-reaction) effects. Furthermore, it is noted that when modified unconfounded autonomic indices have been used, the results failed to support the NP notion. A challenge to the validity of the verbal index of rated intensity is then considered, but it is argued that this verbal index is a valid measure of shock aversiveness. Since the rated-intensity evidence is also generally against the NP notion, it is concluded that both autonomic and verbal indices, when properly evaluated, do not support the view that signaling attenuates shock aversiveness. [ABSTRACT FROM AUTHOR]