Stimulus and Temporal Variables in the “Below‐Zero” Habituation of the Orienting Response

ABSTRACT Three groups of 15 male undergraduate subjects experienced three different habituation conditions: Extended Habituation (20 “below‐zero” trials), Habituation (no “below‐zero” trials), and Spontaneous Recovery Control (no “below‐zero” trials; additional spontaneous recovery time equal to that taken to present 20 “below‐zero” trials). The extended Habituation group showed no signs of strengthened habituation, as spontaneous recovery and trials to rehabituation were not less than in the Habituation group. In fact, the Extended Habituation condition mitigated the effects of habituation, since there was greater spontaneous recovery and more trials to rehabituation relative to the Habituation condition. These paradoxical findings were due primarily to sensitization effects attributable to the “below‐zero” stimuli. Further, it was found that increased spontaneous recovery time also facilitated spontaneous recovery and inhibited rehabituation. The data were seen as providing a link between “below‐zero” habituation and “overhabituation,” and also as providing support for the “dual process” theory of habituation.