Unconscious determinants of free decisions in the human brain.
ABSTRACT There has been a long controversy as to whether subjectively 'free' decisions are determined by brain activity ahead of time. We found that the outcome of a decision can be encoded in brain activity of prefrontal and parietal cortex up to 10 s before it enters awareness. This delay presumably reflects the operation of a network of high-level control areas that begin to prepare an upcoming decision long before it enters awareness.
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ABSTRACT: The interpretation of human consciousness from brain activity, without recourse to speech or action, is one of the most provoking and challenging frontiers of modern neuroscience. We asked whether there is a common neural code that underpins similar conscious experiences, which could be used to decode these experiences in the absence of behavior. To this end, we used richly evocative stimulation (an engaging movie) portraying real-world events to elicit a similar conscious experience in different people. Common neural correlates of conscious experience were quantified and related to measurable, quantitative and qualitative, executive components of the movie through two additional behavioral investigations. The movie's executive demands drove synchronized brain activity across healthy participants' frontal and parietal cortices in regions known to support executive function. Moreover, the timing of activity in these regions was predicted by participants' highly similar qualitative experience of the movie's moment-to-moment executive demands, suggesting that synchronization of activity across participants underpinned their similar experience. Thus we demonstrate, for the first time to our knowledge, that a neural index based on executive function reliably predicted every healthy individual's similar conscious experience in response to real-world events unfolding over time. This approach provided strong evidence for the conscious experience of a brain-injured patient, who had remained entirely behaviorally nonresponsive for 16 y. The patient's executive engagement and moment-to-moment perception of the movie content were highly similar to that of every healthy participant. These findings shed light on the common basis of human consciousness and enable the interpretation of conscious experience in the absence of behavior.Proceedings of the National Academy of Sciences of the United States of America. 09/2014;
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ABSTRACT: In this article we discuss the problem of how to present knowledge claims to the general public by looking at the way in which the data that come from neuroscience in regard to free will are presented in the academic world and by the mass media. These data, whose meaning is indeed still very controversial, are often taken as proving, or a least strongly suggesting, that our most cherished notions – including freedom, responsibility, agency, and rationality – are nothing more than illusions and, consequently, that the very foundations of the current conceptions of morality and the law are irreparably undermined. The effect of this situation is that the messages to the general public are often oversimplified, if not distorted. We will argue that part of the reason of this is that, in order to get resources from public and private investors, research groups tend to emphasize their findings in simplified terms, stressing their novelty and their relevance in order to stir the attention of both the scientific community and the general public. At the same time, the media (including internet-based media) frequently looks for simple and sexy answers in fields in which we are still in the process of trying to formulate good questions.Social Epistemology Review and Reply Collective. 01/2014; 3(12):40-50.
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ABSTRACT: Individuals have a preferred pace at which they perform voluntary repetitive movements. Previous studies have reported that greater activation of the prefrontal cortex was observed during self-initiated movements than during externally triggered movements. The purpose of the present study is to compare the activation of the prefrontal cortex induced when the subjects performed a peg-board task at their preferred slow pace (PSP, the self-initiated condition) with that induced when they performed the same task at metronome slow pace (MSP, the externally triggered condition) using functional near-infrared spectroscopy. Healthy subjects performed the task while sitting in a chair. By assessing the activated channels individually, we confirmed that all of the prefrontal regions of interest were activated by both tasks. In the second-level analyses, we found that the activation detected in the frontopolar cortex (FPPFC; Brodmann area 10) was higher during the PSP task than during the MSP task. The FPPFC is known to be at the top of prefrontal hierarchy, and specifically involved in evaluating self-generated information. In addition, the FPPFC plays a role in coordinating lateral prefrontal cortex. In the present study, the subjects evaluated and managed the internally generated PSP by coordinating the activity of other lower level prefrontal regions.Neural Plasticity 01/2014; 2014:269120. · 2.86 Impact Factor