Adina Roskies

The readiness potential (RP) is one of the most controversial topics in neuroscience and philosophy due to its perceived relevance to the role of conscious willing in action. Libet and colleagues reported that RP onset precedes both volitional movement and conscious awareness of willing that movement, suggesting that the experience of conscious will may not cause volitional movement (Libet, Gleason, Wright, & Pearl, 1983). Rather, they suggested that the RP indexes unconscious processes that may actually cause both volitional movement and the accompanying conscious feeling of will (Libet et al., 1983; pg. 640). Here, we demonstrate that volitional movement can occur without an accompanying feeling of will. We additionally show that the neural processes indexed by RPs are insufficient to cause the experience of conscious willing. Specifically, RPs still occur when subjects make self-timed, endogenously-initiated movements due to a post-hypnotic suggestion, without a conscious feeling of having willed those movements.

This paper explores whether brain images may be admitted as evidence in criminal trials under Federal Rule of Evidence 403, which weighs probative value against the danger of being prejudicial, confusing, or misleading to fact finders. The paper summarizes and evaluates recent empirical research relevant to these issues. We argue that currently the probative value of neuroimages for criminal responsibility is minimal, and there is some evidence of their potential to be prejudicial or misleading. We also propose experiments that will directly assess how jurors are influenced by brain images

Marcelo Fischborn discusses the significance of neuroscience for debates about free will. Although he concedes that, to date, Libet-style experiments have failed to threaten “libertarian free will”, he argues that, in principle, neuroscience and psychology could do so by supporting local determinism. We argue that, in principle, Libet-style experiments cannot succeed in disproving or even establishing serious doubt about libertarian free will. First, we contend that “local determination”, as Fischborn outlines it, is not a coherent concept. Moreover, determinism is unlikely to be established by neuroscience in any form that should trouble compatibilists or libertarians—that is, anyone who thinks we might have free will. We conclude that, in principle, neuroscience will not be able undermine libertarian free will and explain why these conclusions support a coherent compatibilist notion of causal sourcehood.