Neural correlates of consciousness reconsidered

It is widely accepted among philosophers that neuroscientists are conducting a search for the neural correlates of consciousness, or NCC. Chalmers (2000) conceptualized this research program as the attempt to correlate the contents of conscious experience with the contents of representations in specific neural populations. A notable claim on behalf of this interpretation is that the neutral language of "correlates" frees us from philosophical disputes over the mind/body relation, allowing the science to move independently. But the experimental paradigms and explanatory canons of neuroscience are not neutral about the mechanical relation between consciousness and the brain. I argue that NCC research is best characterized as an attempt to locate a causally relevant neural mechanism and not as an effort to identify a discrete neural representation, the content of which correlates with some actual experience. It might be said that the first C in "NCC" should stand for "causes" rather than "correlates."     

Autopoiesis and Darwinism

The purpose of this paper is to offer a critical approach to the theory of autopoiesis in order to see how it challenges mainstream Darwinism. In the first part of the paper, I characterize Darwinism from the concepts of natural selection, heredity, reproduction, and evolution. This characterization is absolutely schematic, and I hope not controversial at all, since my aim is to provide a general background for the discussion of the rest of the paper. The second part presents the main tenets of the theory of autopoiesis, also paying special attention to the concepts of natural selection, heredity, reproduction, and evolution. The third and final part considers some criticisms that have been directed against the theory and suggests some new ones. As I said, my intention is to offer a critical approach, so that I pretend to assess neither autopoiesis nor Darwinism. The assessment, it seems to me, would be a matter of scientific debate—not properly of philosophy. Therefore, given that my approach attempts to be a conceptual clarification, my contribution to the contemporary debate about Darwinism is twofold. On the one hand, I show that conceptually autopoiesis constitutes an important challenge to Darwinism, but on the other, I also show that some fundamental aspects of the theory appear to be both epistemologically and empirically problematic, which perhaps helps to understand why autopoiesis is not widely accepted in mainstream Darwinism.     

Informational Darwinism

The Theory of Evolution has, since Darwin, been sustained by contributions from many sciences, most especially from molecular biology. Philosophers, like biologists and the man in the street, have accepted the idea that the contemporary form of evolutionary theory has arrived at a convincing and final structure. As it now stands, natural selection is thought to work through the information-handling mechanism of the DNA molecule. Variation in the genome?s constructive message is achieved through random errors of processing called mutations. How that mechanism and its revision works, and how much information it can hold are fundamental questions for the Neo-Darwinian theory to face. It is argued here that neither the operation nor the data content of the genome, as science understand them, can underpin the role Darwinism assigns to natural selection. It follows that we cannot put our confidence in the explanatory force of Darwinian reasoning, but neither is there an alternative to it.     

Neural synchrony in stochastic resonance, attention, and consciousness.

We describe briefly three of our lab's ongoing projects studying the role of neural synchrony in human perception and cognition. These projects arise from two main interests: the role of noise both in human perception and in neural synchrony, and neural synchrony as a basis for integration of functional modules in the brain. Our experimental work on these topics began with a study of the possibility that noise-influenced neural synchrony might be responsible for the fact that small amounts of noise added to weak signals can enhance their detectability (stochastic resonance). We are also studying the role of neural synchrony in attention and consciousness in several paradigms. On the basis of our own and related work by others, we conclude that (1) neural synchrony plays an important role in the integration of functional modules in the brain and (2) neural synchrony is profoundly affected and possibly regulated, in part, by the "noisiness" of the brain.     

Identification and integration of sensory modalities: Neural basis and relation to consciousness

A key question in studying consciousness is how neural operations in the brain can identify streams of sensory input as belonging to distinct modalities, which contributes to the representation of qualitatively different experiences. The basis for identification of modalities is proposed to be constituted by self-organized comparative operations across a network of unimodal and multimodal sensory areas. However, such network interactions alone cannot answer the question how sensory feature detectors collectively account for an integrated, yet phenomenally differentiated experiential content. This problem turns out to be different from, although related to, the binding problem. It is proposed that the neural correlate of an enriched, multimodal experience is constituted by the attractor state of a dynamic associative network. Within this network, unimodal and multimodal sensory maps continuously interact to influence each other’s attractor state, so that a feature change in one modality results in a fast re-coding of feature information in another modality. In this scheme, feature detection is coded by firing-rate, whereas firing phase codes relational aspects.     

皮尔逊的社会达尔文主义

英国哲人科学家卡尔·皮尔逊 (KarlPearson ,185 7～ 193 6)是一位社会达尔文主义者 ,他运用进化论思想探究了无机世界、人的历史进化、自然选择、道德、民族问题、人类和社会。在这个过程中 ,他既提出了某些富有启发性的见解 ,也在一定程度上宣扬了种族主义和殖民主义的谬论。在整个 19世纪 ,自然科学的方法和发现使社会研究发生了革命性的变化。维多利亚女王 (1819～ 190 1)时代的社会理论家都坚持认为 ,实证科学不得不改造知识的逻辑 ,从而改造伦理、政治和宗教。尤其是在达尔文的《物种起源》 (185 9)出版之前 ,英国理论家就开始用进化…     

Theology and the Crisis in Darwinism

In the past decade, the scientific challenges to “orthodox Darwinism” have multiplied rapidly, such that it is no longer unthinkable that natural selection’s days as a universal law are numbered. But if this is the case, theologians have their work cut out for them. If Darwin’s law proves to be historically and scientifically false, a new horizon appears for the discourse between theology and natural science. What will orthodox Christianity make of the crisis in Darwinism? This article, which follows the methodological imperative of “Radical Orthodoxy”, employs Aquinas and contemporary “post‐Darwinian” science to trace a space for a theological discourse beyond both natural selection and natural theology.     

Emotion and consciousness

Consciousness and emotion feature prominently in our personal lives, yet remain enigmatic. Recent advances prompt further distinctions that should provide more experimental traction: we argue that emotion consists of an emotion state (functional aspects, including emotional response) as well as feelings (the conscious experience of the emotion), and that consciousness consists of level (e.g. coma, vegetative state and wakefulness) and content (what it is we are conscious of). Not only is consciousness important to aspects of emotion but structures that are important for emotion, such as brainstem nuclei and midline cortices, overlap with structures that regulate the level of consciousness. The intersection of consciousness and emotion is ripe for experimental investigation, and we outline possible examples for future studies.     

Dreaming and consciousness

Abstract

Research in the second half of the twentieth century may finally have succeeded in constraining the boundaries of reasonable discussion about dreams and dreaming. Largely owing to physiological discoveries and psychophysiological methods for the representative sampling of human dreamlife, we now have a body of observations that delimits plausible explanations and theories.

For example, we now know that neither REM sleep nor its dreaming is a sporadic, fleeting response to intense psychic needs or peripheral organ states, but rather is an autonomous, cyclically recurring process which consumes relatively much of our sleep, indeed of our lives. We also know that the content of representatively sampled dreams of both adults (Snyder, 1970) and children (Foulkes, 1982) is generally realistic and mundane, rather than fantastic and bizarre. From this finding, and from direct com parisons of representatively sampled laboratory-collected dreams with spon taneously remembered home dreams (e.g. Foulkes. 1979). it has become apparent that the idea of dreaming as being full of strange and discontinuous imagery is a stereotype based on limited acquaintance with our own dreamlife. Specifically, our most ordinarily memorable dreams seem to be those relatively few that are particularly emotionally engaging, particularly unrealistic, or particularly odd in their imagery or thematic sequence. This leads us to underestimate the orderliness of a process that typically functions plausibly and coherently, in a similar if not identical manner to that which we believe (perhaps also stereotypically) characterises our non-dreaming experience.

Thus, studies of representatively sampled dreaming have shown that dream imagery itself typically is realistic or plausible (Dorus, Dorus, & Rechtschaffen, 1971). that dream speech typically is both grammatically correct and appropriate to the imagined situation in which it is embedded (Heynick, 1983). that the feelings accompanying dream imagery typically are appropriate to the imagined situations which they accompany (Foulkes, Sullivan, Kerr, & Brown, 1988), and that, overwhelmingly often, dreams progress over time in a continuous rather than a discontinuous way (Foulkes & Schmidt, 1983).

Such data indicate the need to radically revise or replace most older dream theories from the clinical tradition. Given the role that physiologists and physiological methods played in the development of these data, it was perhaps inevitable that dream theories would begin to be framed in reductionist terms. And, since the 19505, there have been many attempts to “explain” dream phenomena through their reduction to neurophysiological processes (e.g. Crick & Mitchison, 1983; Hobson & McCarley, 1977)