“…evidence persists in the psychological literature that people’s bodies sometimes unconsciously “predict” unpredictable future events. These visceral responses don’t appear to be the result of sheer chance. That’s the result of a meta-analysis of earlier papers on this subject conducted by a trio of researchers led by Julia Mossbridge of Northwestern University.
…What the studies measured was physiological activity—e.g., heart rate or skin conductance—in participants who, for instance, might have been shown a series of images, some harmless and others frightening. Using computer programs and statistical techniques, experimenters have found that, even before being shown a troubling image, participants sometimes display physiological changes —a faster heart rate, for example—of the kind that would be expected only after seeing the image, and not just because the subjects know a scary snake picture is coming sooner or later. ”