Patricia Churchland

Using the Gödel Incompleteness Result for leverage, Roger Penrose has argued that the mechanism for consciousness involves quantum gravitational phenomena, acting through microtubules in neurons. We show that this hypothesis is implausible. First, the Gödel Result does not imply that human thought is in fact non algorithmic. Second, whether or not non algorithmic quantum gravitational phenomena actually exist, and if they did how that could conceivably implicate microtubules, and if microtubules were involved, how that could conceivably implicate consciousness, is entirely speculative. Third, cytoplasmic ions such as calcium and sodium are almost certainly present in the microtubule pore, barring the quantum mechanical effects Penrose envisages. Finally, physiological evidence indicates that consciousness does not directly depend on microtubule properties in any case, rendering doubtful any theory according to which consciousness is generated in the microtubules

The study of morality is increasingly an interdisciplinary endeavor spanning the cognitive, social, and biological sciences. This article provides an overview and synthesis of recent work fields relevant to the scientific understanding of morality, with a focus on how moral judgment and behavior are rooted in the functioning, development, and evolution of the brain. It presents themes that have emerged from studies examining the cognitive processes involved in morality. It shows studies that directly investigate the neural substrates of morality using modern brain imaging techniques. A number of brain regions and systems are identified that appear to be essential for normal moral behavior. The article focuses on two clinical conditions: lesions to the prefrontal cortex and psychopathy. Furthermore, it discusses neuroendocrinology and evolutionary neurobiology—that is relevant to understanding the development of morality and concerns evolutionary history and functions of two neuropeptides, oxytocin and vasopressin, in the mammalian brain and their effects on behavior.

Using the Godel incompleteness result for leverage, Roger Penrose has argued that the mechanism for consciousness involves quantum gravitational phenomena, acting through microtubules in neurons. We show that this hypothesis is implausible. First the Godel result does not imply that human thought is in fact non-algorithmic. Second, whether or not non-algorithmic quantum gravitational phenomena actually exist, and if they did how that could conceivably implicate microtubules, and if microtubules were involved, how that could conceivably implicate consciousness, is entirely speculative. Third, cytoplasmic ions such as calcium and sodium are almost certainly present in the microtubule pore, barring the quantum-mechanical effects Penrose envisages. Finally, physiological evidence indicates that consciousness does not directly depend on microtubule properties in any case, rendering doubtful any theory according to which consciousness is generated in the microtubules

Two very different insights motivate characterizing the brain as a computer. One depends on mathematical theory that defines computability in a highly abstract sense. Here the foundational idea is that of a Turing machine. Not an actual machine, the Turing machine is really a conceptual way of making the point that any well-defined function could be executed, step by step, according to simple 'if-you-are-in-state-P-and-have-input-Q-then-do-R' rules, given enough time (maybe infinite time) [see COMPUTATION]. Insofar as the brain is a device whose input and output can be characterized in terms of some mathematical function -- however complicated -- then in that very abstract sense, it can be mimicked by a Turning machine. Given what is known so far brains do seem to depend on cause-effect operations, and hence brains appear to be, in some formal sense, equivalent to a Turing machine [see CHURCH-TURING THESIS]. On its own, however, this reveals nothing at all of how the mind-brain actually works. The second insight depends on looking at the brain as a biological device that processes information from the environment to build complex representations that enable the brain to make predictions and select advantageous behaviors. Where necessary to avoid ambiguity, we will refer to the first notion of computation as.

Two very different insights motivate characterizing the brain as a computer. One depends on mathematical theory that defines computability in a highly abstract sense. Here the foundational idea is that of a Turing machine. Not an actual machine, the Turing machine is really a conceptual way of making the point that any well-defined function could be executed, step by step, according to simple 'if-you-are-in-state-P-and-have-input-Q-then-do-R' rules, given enough time (maybe infinite time) [see COMPUTATION]. Insofar as the brain is a device whose input and output can be characterized in terms of some mathematical function -- however complicated -- then in that very abstract sense, it can be mimicked by a Turning machine. Given what is known so far brains do seem to depend on cause-effect operations, and hence brains appear to be, in some formal sense, equivalent to a Turing machine [see CHURCH-TURING THESIS]. On its own, however, this reveals nothing at all of how the mind-brain actually works. The second insight depends on looking at the brain as a biological device that processes information from the environment to build complex representations that enable the brain to make predictions and select advantageous behaviors. Where necessary to avoid ambiguity, we will refer to the first notion of computation as algorithmic computation, and the second as information processing computation.

Morality is often defined in opposition to the natural "instincts," or as a tool to keep those instincts in check. New findings in neuroscience, social psychology, animal behaviour, and anthropology have brought us back to the original Darwinian position that moral behaviour is continuous with the social behavior of animals, and most likely evolved to enhance the cooperativeness of society. In this view, morality is part of human nature rather than its opposite. This interdisciplinary volume debates the origin and working of human morality within the context of science as well as religion and philosophy. Experts from widely different backgrounds speculate how morality may have evolved, how it develops in the child, and what science can tell us about its working and origin. They also discuss how to deal with the age-old facts-versus-values debate, also known as the naturalistic fallacy. The implications of this exchange are enormous, as they may transform cherished views on if and why we are the only moral species.

De nos jours existe un extraordinaire engouement pour les sciences du cerveau qui captivent de plus en plus de penseurs. Des philosophes americains encouragent leurs pairs a s'initier aux neurosciences. Des hommes de science, conscients des enjeux metaphysiques inherents a leur domaine, invitent les philosophes a decouvrir les faits nouveaux apportes par les decouvertes sur le systeme nerveux. Il parait donc legitime que le philosophe soit concerne par les developpements recents des sciences du cerveau. Par la diversite des points de vus et des perspectives, le present recueil souhaite contribuer a eclairer, dans la mesure du possible, quelques-unes des questions inherentes aux interactions entre la philosophie et les neurosciences.

As neuroscience has intensely developed in the twentieth and twenty-first centuries, we increasingly see neurobiological results that bear upon age-old philosophical questions about the mind and its relation to the brain. Although neuroscience has not yet completely answered questions about learning and memory, or about attention, social impulses and sleep, for all these topics there are now relevant results. These results suggest that more can and will be understood in the coming years, especially as new techniques and methods are discovered and applied. Arguments from philosophers regarding why consciousness in particular cannot ever be explained neurobiologically are also critically examined. On this contentious topic too, clinical neurologists in particular have sought ways of determining the conscious status of their patients in order better to treat them. Even on this topic there is early but promising neurobiological progress. ER -