The timing of brain events: Reply to the “Special Section” in this journal of September 2004, edited by Susan Pockett

In this “Reply” paper, the arguments and experimental findings by Pockett, Pollen, and Haggard et al. are analyzed. It had been shown (Libet et al., 1964) that a 0.5 s duration of repetitive activations of sensory cortex is required to produce a threshold of sensation. The view that this is due to a facilitatory buildup in excitatory state to finally elicit neuronal firing is shown to be incompatible with several lines of evidence. Objections to the phenomenon of subjective referral backwards in time (for the delayed sensation) are also untenable. Haggard, Cartledge, Dafydd, and Oakley (2004) report that a self-initiated act can, under hypnotic suggestion, appear to the subject to be “involuntary.” The act under hypnosis is better viewed as one initiated unconsciously, not as an act of conscious will.