Does Psychophysiological Predictive Anticipatory Activity Predict Real or Future Probable Events

The possibility of predicting random future events before any sensory clues by using human physiology as a dependent variable has been supported by the meta-analysis of Mossbridge et al.1 and by recent findings by Tressoldi et al.2,3. Mossbridge et al.4 defined this phenomenon predictive anticipatory activity (PAA).From a theoretical point of view, one interesting question is whether PAA is related to the effective, real future presentation of these stimuli or whether it is related only to the probability of their presentation.This hypothesis was tested with four experiments two using heart rate and two using pupil dilation as dependent variables.In all four experiments, both a neutral and a potentially threatening stimulus were predicted 7 to 10% above chance, independently from whether the predicted threatening stimulus was presented or not.These findings are discussed with reference to the “grandfather paradox” and some candidate explanations for this phenomena are presented.