Over the last decade in Germany, a number of neuroscientists—and among them most prominently Wolf Singer—have claimed to be able to offer scientific evidence derived from neurophysiologic findings to conclusively negate the existence of human free will. In this paper, Singer’s position is examined according to its principal characteristics in order to answer the question whether it is a novel position as opposed to a position pertaining to one of the traditions of western philosophy and anthropology. Furthermore, we try to (...) judge whether the neurobiological findings Singer and others use to justify their position are apt to satisfy the criteria for the presence of scientific evidence, i.e., if they are good reasons to believe that human will is unfree. (shrink)
The excellent and highly interesting commentaries address the following concerns: (1) neuroanatomy and neurophysiology of catatonia; (2) cognitive-motor deficits in catatonia; (3) conceptual issues; (4) general methodology in neuropsychiatric research; and (5) neurophilosophical implications. The specific problems, issues, and aspects raised by the different commentators are grouped under these categories in Table R1 presented below. These five areas of concern are then discussed in the order listed in the five sections of the Response.
A unifying theory of general anesthetic-induced unconsciousness must explain the common mechanism through which various anesthetic agents produce unconsciousness. Functional-brain-imaging data obtained from 11 volunteers during general anesthesia showed specific suppression of regional thalamic and midbrain reticular formation activity across two different commonly used volatile agents. These findings are discussed in relation to findings from sleep neurophysiology and the implications of this work for consciousness research. It is hypothesized that the essential common neurophysiologic mechanism underlying anesthetic-induced unconsciousness is, as (...) with sleep-induced unconsciousness, a hyperpolarization block of thalamocortical neurons. A model of anesthetic-induced unconsciousness is introduced to explain how the plethora of effects anesthetics have on cellular functioning ultimately all converge on a single neuroanatomic/neurophysiologic system, thus providing for a unitary physiologic theory of narcosis related to consciousness. (shrink)
Action is to be distinguished from (mere) bodily movement not by reference to an agent's intentions, or his conscious control of his movements (Sect. I), but by reference to the agent as cause of those movements, though this needs to be understood in a way which destroys the alleged distinction between agent-causation and event-causation (Sect. II). It also raises the question of the relation between an agent and his neurophysiology (Sect. III), and eventually the question of the compatibility of (...) purposive and mechanistic accounts of human behaviour (Sect. IV). For the two to be compatible it is necessary that, e.g., intentions and brain states be not merely co-existent but also causal equivalents, in a way which allows for the mechanical explanation of teleological states — or vice versa. (shrink)
Information processing theories of memory and skills can be reformulated in terms of how categories are physically and temporally related, a process called conceptual coordination. Dreaming can then be understood as a story-understanding process in which two mechanisms found in everyday comprehension are missing: conceiving sequences (chunking categories in time as a higher-order categorization) and coordinating across modalities (e.g., relating the sound of a word and the image of its meaning). On this basis, we can readily identify isomorphisms between dream (...) phenomenology and neurophysiology, and explain the function of dreaming as facilitating future coordination of sequential, cross-modal categorization (i.e., REM sleep lowers activation thresholds, “unlearning”). [Hobson et al.; Nielsen; Solms; Revonsuo; Vertes & Eastman]. (shrink)
In the first two sections of the paper, some basic terminological distinctions regarding “freedom of the will” as a philosophical problem are expounded and discussed. On this basis, the third section focuses on the examination of two neurophysiological experiments (one by Benjamin Libet and one by William Grey Walter), which in recent times are often interpreted as providing an empirical vindication of determinism and, accordingly, a refutation of positions maintaining freedom of the will. It will be argued that both experiments (...) fall short in this respect, and that in general—for methodical reasons—the prospects of ever deciding the dispute about freedom of the will through empirical research are rather poor. (shrink)
Durkheimian solidarity, especially in regard to religion, is reanalyzed in terms of recent developments in the neurosciences and evolution. Neurophysiological studies indicate that religious arousers can piggyback on reward circuitry established by natural selection for interpersonal attachments. This piggybacking is rooted in uneven evolutionary changes in cognitive capacities, emotional arousal capabilities, and preconscious screening rules for rewarding arousal release. Uneven development means that only a special class of enhanced arousers embedded in macro social structures can tap some of the reservoirs (...) of expanded arousal release protected by these screening rules. It becomes imperative that part of collective social life offers these special arouser packages. Beginning with religion and inequality, the social construction of enhanced arousers leaves a trail across human history. However, this trail is not quite what Durkheim had in mind. (shrink)
A broad range of evidence regarding the functional organization of the vertebrate brain – spanning from comparative neurology to experimental psychology and neurophysiology to clinical data – is reviewed for its bearing on conceptions of the neural organization of consciousness. A novel principle relating target selection, action selection, and motivation to one another, as a means to optimize integration for action in real time, is introduced. With its help, the principal macrosystems of the vertebrate brain can be seen to (...) form a centralized functional design in which an upper brain stem system organized for conscious function performs a penultimate step in action control. This upper brain stem system retained a key role throughout the evolutionary process by which an expanding forebrain – culminating in the cerebral cortex of mammals – came to serve as a medium for the elaboration of conscious contents. This highly conserved upper brainstem system, which extends from the roof of the midbrain to the basal diencephalon, integrates the massively parallel and distributed information capacity of the cerebral hemispheres into the limited-capacity, sequential mode of operation required for coherent behavior. It maintains special connective relations with cortical territories implicated in attentional and conscious functions, but is not rendered nonfunctional in the absence of cortical input. This helps explain the purposive, goal-directed behavior exhibited by mammals after experimental decortication, as well as the evidence that children born without a cortex are conscious. Taken together these circumstances suggest that brainstem mechanisms are integral to the constitution of the conscious state, and that an adequate account of neural mechanisms of conscious function cannot be confined to the thalamocortical complex alone. (Published Online May 1 2007) Key Words: action selection; anencephaly; central decision making; consciousness; control architectures; hydranencephaly; macrosystems; motivation; target selection; zona incerta. (shrink)
This paper discusses Wittgenstein's ideas about the relation between thought, neurophysiology and language, and about the mental capacities of non-linguistic animals. It deals with his initial espousal and later rejection of a 'language of thought', his arguments against the idea that thought requires a medium of images or words, his reasons for resisting the encephalocentric conception of the mind which dominates contemporary philosophy of mind, his mature views about the connection between thought and language, and his remarks about animals. (...) The aim is not just to get a clear picture of Wittgenstein's position, but also to contrast it with contemporary approaches such as those of Fodor and Searle. While rejecting some of Wittgenstein's claims about the role of the brain, I defend his basic idea, namely that the capacity for entertaining a thought is conceptually tied to the capacity for displaying that thought in behaviour, rather than to the possession of language as such or to the occurrence of specific neurophysiological phenomena. (shrink)
David Marr's theory of vision has been widely cited by philosophers and psychologists. I have three projects in this paper. First, I try to offer a perspicuous characterization of Marr's theory. Next, I consider the implications of Marr's work for some currently popular philosophies of psychology, specifically, the "hegemony of neurophysiology view", the theories of Jerry Fodor, Daniel Dennett, and Stephen Stich, and the view that perception is permeated by belief. In the last section, I consider what the phenomenon (...) of vision must be like for Marr's project to succeed. (shrink)
We briefly describe ways in which neuroeconomics has made contributions to its contributing disciplines, especially neuroscience, and a specific way in which it could make future contributions to both. The contributions of a scientific research programme can be categorized in terms of (1) description and classification of phenomena, (2) the discovery of causal relationships among those phenomena, and (3) the development of tools to facilitate (1) and (2). We consider ways in which neuroeconomics has advanced neuroscience and economics along each (...) line. Then, focusing on electrophysiological methods, we consider a puzzle within neuroeconomics whose solution we believe could facilitate contributions to both neuroscience and economics, in line with category (2). This puzzle concerns how the brain assigns reward values to otherwise incomparable stimuli. According to the common currency hypothesis, dopamine release is a component of a neural mechanism that solves comparability problems. We review two versions of the common currency hypothesis, one proposed by Read Montague and colleagues, the other by William Newsome and colleagues, and fit these hypotheses into considerations of rational choice. (shrink)
The papers collected in this volume explore some of the powers and limitations of the concept of mechanism for the scientific understanding of cognitive systems, and aim at bringing together some of the most recent developments in the philosophical understanding of the relation of cognition to neuroscience. Earlier versions of most papers have been presented at a workshop held in Paris on June 19th, 2006, which was organized by Institut Jean Nicod and supported by RESCIF (R seau des sciences cognitives (...) en Ile-de-France). (shrink)
Short-term memory, nonattentional task effects and nonspatial extraretinal representations in the visual system are signs of cognitive penetration. All of these have been found physiologically, arguing against the cognitive impenetrability of vision as a whole. Instead, parallel subcircuits in the brain, each subserving a different competency including sensory and cognitive (and in some cases motor) aspects, may have cognitively impenetrable components.
Probably colour is the best worked-out example of allegedly neurophysiologically innate response categories determining percepts and percepts determining concepts, and hence biology fixing the basic categories implicit in the use of language. In this paper I argue against this view and I take C. L. Hardin's Color for Philosophers  as my main target. I start by undermining the view that four unique hues stand apart from all other colour shades (Section 2) and the confidence that the solar spectrum is (...) naturally divided into four categories (Section 3). For such categories to be truly universal, they have to be true for all peoples and in Section 4 I show that Berlin and Kay's  widely quoted theory of basic colour categories is not sufficiently supported to lend it any credibility. Having disposed of the view that inspection of language or ?pure? perception unveils the universal colour categories. I turn to neurophysiological and psychophysical theories of colour vision to see whether they provide a more solid basis for deciding what the innate response categories are. In Section 5 I show that Hardin's account of the opponent-process theory neither supports his view that ?colour-coding?takes place early in the visual neural pathway, nor his view that knowledge of colour vision science will help us solve many philosophical mysteries about colour. In Section 6 I give a more detailed review of what is known today about the neurophysiology of colour vision and I show that there's nothing in the brain which could be called a colour module, let alone a module with homunculi for particular basic colour categories. In Section 7 I show that psychophysical models do not support such rigid constraints on category formation either. Hence (Section 8), at least in the case of colour, current science supports a plasticity in the formation of categories that goes far beyond the requirements of those naturalistic philosophers who would like to ground primitive concepts in biology. (shrink)
Embodied cognitive science holds that cognitive processes are deeply and inescapably rooted in our bodily interactions with the world. Our finite, contingent, and mortal embodiment may be not only supportive, but in some cases even constitutive of emotions, thoughts, and experiences. My discussion here will work outward from the neuroanatomy and neurophysiology of the brain to a nervous system which extends to the boundaries of the body. It will extend to nonneural aspects of embodiment and even beyond the boundaries (...) of the body to prosthetics of various kinds, including symbioses with a broad array of cultural artifacts, our symbolic niche, and our relationships with other embodied human beings. While cognition may not always be situated, its origins are embedded in temporally and spatially limited activities. Cognitive work also can be off-loaded to the body and to the environment in service of action, tool use, group cognition, and social coordination. This can blur the boundaries between brain areas, brain and body, and body and environment, transforming our understanding of mind and personhood to provide a different grounding for faith traditions in general, and of the historically dualist Christian tradition in particular. (shrink)
One of the most paradoxical aspects of human language is that it is so unlike any other form of behavior in the animal world, yet at the same time, it has developed in a species that is not far removed from ancestral species that do not possess language. While aspects of non-human primate and avian interaction clearly constitute communication, this communication appears distinct from the rich, combinatorial and abstract quality of human language. So how does the human primate brain allow (...) for language? In an effort to answer this question, a line of research has been developed that attempts to build a language processing capability based in part on the gross neuroanatomy of the corticostriatal system of the human brain. This paper situates this research program in its historical context, that begins with the primate oculomotor system and sensorimotor sequencing, and passes, via recent advances in reservoir computing to provide insight into the open questions, and possible approaches, for future research that attempts to model language processing. One novel and useful idea from this research is that the overlap of cortical projections onto common regions in the striatum allows for adaptive binding of cortical signals from distinct circuits, under the control of dopamine, which has a strong adaptive advantage. A second idea is that recurrent networks with fixed connections can represent arbitrary sequential and temporal structure, which is the basis of the reservoir computing framework. Finally, bringing these notions together, a relatively simple mechanism can be built for learning the grammatical constructions, as the mappings from surface structure of sentences to their meaning. This research suggests that the components of language that link conceptual structure to grammatical structure may be much simpler that has been proposed in other research programs. It also suggests that part of the residual complexity is in the conceptual system itself. (shrink)
There has been considerable optimism recently, among philosophers and neuroscientists, concerning the prospect for major discoveries about the neurophysiological basis of mind. The support for this optimism has been extremely abstract and general. I wish to present some grounds ..