Talk:Feeling the Future

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Bem has published his own research methodology and encourages the formulation of hypotheses after data analysis. This form of post-hoc analysis makes it very difficult to determine accurate statistical significance. It also explains why Bem offers specific hypotheses that seem odd a priori, such as erotic images having a greater precognitive effect. Constructing hypotheses from the same data range used to test those hypotheses is a classic example of the Texas sharpshooter fallacy

The hypothesis that erotic images would have a greater effect likely stems from "ANOMALOUS ANTICIPATORY BRAIN ACTIVATION PRECEDING EXPOSURE OF EMOTIONAL AND NEUTRAL PICTURES" by Dick J. Bierman and H. Steven Scholte (2002). Bem cites this on the fourth page of his paper:

Most of the pictures were emotionally neutral, but a highly arousing negative or erotic image was displayed on randomly selected trials. As expected, strong emotional arousal occurred when these images appeared on the screen, but the remarkable finding is that the increased arousal was observed to occur a few seconds before the picture appeared, before the computer has even selected the picture to be displayed. The presentiment effect has also been demonstrated in an fMRI experiment that monitored brain activity (Bierman & Scholte, 2002) and in experiments using bursts of noise rather than visual images as the arousing stimuli (Spottiswoode & May, 2003).

As such, it is not clear to me that the "Texas sharpshooter" fallacy applies here. Exaggerated effects from erotic images has been suggested by prior experiments in the field. This makes the hypothesis ("the main psi hypothesis was that participants would be able to identify the position of the hidden erotic picture significantly more often than chance (50%)") a perfectly reasonable a priori hypothesis.— Unsigned, by: Johnlaptop / talk / contribs