Threatening scenes but not threatening faces shorten time-to-contact estimates

We previously reported that time-to-contact (TTC) judgments of threatening scene pictures (e.g., frontal attacks) resulted in shortened estimations and were mediated by cognitive processes, and that judgments of threatening (e.g., angry) face pictures resulted in a smaller effect and did not seem cognitively mediated. In the present study, the effects of threatening scenes and faces were compared in two different tasks. An effect of threatening scene pictures occurred in a prediction-motion task, which putatively requires cognitive motion extrapolation, but not in a relative TTC judgment task, which was designed to be less reliant on cognitive processes. An effect of threatening face pictures did not occur in either task. We propose that an object's explicit potential of threat per se, and not only emotional valence, underlies the effect of threatening scenes on TTC judgments and that such an effect occurs only when the task allows sufficient cognitive processing. Results are consistent with distinctions between predator and social fear systems and different underlying physiological mechanisms. Not all threatening information elicits the same responses, and whether an effect occurs at all may depend on the task and the degree to which the task involves cognitive processes.