On the validity of the preception hypothesis.

The preception hypothesis holds that when an aversive stimulus is made predictable in time, S may be able to inhibit his arousal response to that stimulus and thus reduce its aversiveness or impact. In response to a paper by Furedy and Klajner, which questions the validity of the preception hypothesis, it is argued that considerable behavioral and autonomic response data seem to support this hypothesis. The present authors, in particular, do not share Furedy and Klajner's view that OR theory developed to explain habituation should also be adopted to account for the findings attributed to preception. On the contrary, preception is proposed to be a distinct process playing a role complementary to that of habituation, more labile and also more effortful in the sense that it requires the involvement of the “second signal system,” while habituation can apparently proceed as a non-cognitive, automatic process. However, Furedy and Klajner's discussion suggests the fruitfulness of additional investigations to test more decisively differential predictions based on an habituation vs a preception position. Even if accepted the preception mechanism could ultimately be incorporated in an elaborated version of OR theory.