S. Pockett and G. Gomes discuss a possible bias in the method by which Libet's subjects estimated the time at which they became aware of their intent to move their hands. The bias, caused by sensory delay processing the clock information, would be sufficient to alter Trevena and Miller's conclusions regarding the timing of the lateralized readiness potential. I show that the flash-lag effect would compensate for that bias. In the last part of my commentary I note that the other (...) target articles do not examine the most interesting aspect of Libet's unfashionable views on free will. I point out that Libet's views are less strange than they at first appear to be. (shrink)

This issue of Consciousness and Cognition presents four target articles and eight commentaries on the target articles. The present article presents comments on those commentaries, grouped into backward referral and volition categories. Regarding backward referral: I disagree with my fellow commentators and take the unpopular position of defending Libet's notion of backward referral. I join my fellow commentators in critiquing Libet's notion of a 500-ms delay. I examine several of the hypotheses suggested by other commentators for why cortical and lateral (...) meniscus stimulation give very different timing results. I suggest a simple experiment to help discriminate among the hypotheses. I comment on why temporal reordering is more likely to occur late rather than early in mental processing. Regarding Libet's volition experiments, I ask what is the root of the controversy, given the general agreement on the data. I agree with a commentator that Libet's chronotheology rather than his chronoscience is the cause of much of the controversy. Rather than joining others in criticizing Libet for his chronotheology I point out that he is making a respectable philosophical point regarding nondeterministic Free Will, but one that is easily misunderstood. I discuss two ways by which Libet's viewpoint can be brought into mainstream science. (shrink)

An extended examination of Libet's works led to a comprehensive reinterpretation of his results. According to this reinterpretation, the Minimum Train Duration of electrical brain stimulation should be considered as the time needed to create a brain stimulus efficient for producing conscious sensation and not as a basis for inferring the latency for conscious sensation of peripheral origin. Latency for conscious sensation with brain stimulation may occurafterthe Minimum Train Duration. Backward masking with cortical stimuli suggests a 125-300 ms minimum value (...) for the latency for conscious sensation of threshold skin stimuli. Backward enhancement is not suitable for inferring this latency. For determining temporal relations between stimuli that correspond to subjects' reports, theendof cerebral Minimum Train Duration should be used as reference, rather than its onset. Results of coupling peripheral and cortical stimuli are explained by a latency after the cortical Minimum Train Duration, having roughly the same duration as the latency for supraliminal skin stimuli. Results of coupling peripheral stimuli and stimuli to medial lemniscus (LM) are explained by a shorter LM latency and/or a longer peripheral latency. This interpretation suggests a 230 ms minimum value for the latency for conscious sensation of somatosensory near-threshold stimuli. The backward referral hypothesis, as formulated by Libet, should not be retained. Long readiness potentials preceding spontaneous conscious or nonconscious movements suggest that both kinds of movement are nonconsciously initiated. The validity of Libet's measures of W and M moments (Libet et al., 1983a) is questionable due to problems involving latencies, training, and introspective distinction of W and M. Veto of intended actions may be initially nonconscious but dependent on conscious awareness. (shrink)

ABSTRACT For a long time, the question of the existence of free will has fueled philosophical debate with no definitive solution. Libet’s paradigm (1983) seemed to demonstrate that simple and apparently voluntary movements could be triggered not by consciousness, but by preconscious or random brain processes. Such findings had wide repercussions in the academic and scientific circles, triggering an extensive discussion among neuroscientists, philosophers and jurists. Exploring the interfaces between neuroscience and free will, the present work aims to formulate an (...) updated synthesis of the diverse problematizations about the Libetian findings. It appears that Libet’s essay, although repeatedly analyzed and replicated in recent decades, still lacks a definitive interpretation, in part due to methodological controversies and specific conceptual shortcomings. The deepening of these investigations, combined with the new discoveries offered by neuroscience, can enrich research on free will in the coming years. (shrink)

This is a collection of articles and essays that bear on the relationship between scientific and poetical/romantic views of the world.

In this paper I examine Daniel M. Wegner's line of argument against the causal efficacy of conscious will, as presented in Wegner's book "The Illusion of Conscious Will" (Cambridge, MA: The MIT Press, 2002). I argue that most of the evidence adduced in the book can be interpreted in ways that do not threaten the efficacy of conscious will. Also, I argue that Wegner's view of conscious will is not an empirical thesis, and that certain views of consciousness and the (...) self are immune to Wegner's line of argument. (shrink)