The most important scientific discovery of the present era will come when someone -- or some group -- discovers the answer to the following question: How exactly do neurobiological processes in the brain cause consciousness? This is the most important question facing us in the biological sciences, yet it is frequently evaded, and frequently misunderstood when not evaded. In order to clear the way for an understanding of this problem. I am going to begin to answer four questions: 1. What (...) is consciousness? 2. What is the relation of consciousness to the brain? 3. What are some of the features that an empirical theory of consciousness should try to explain? 4. What are some common mistakes to avoid? (shrink)

Evidence and theory ranging from traditional philosophy to contemporary cognitive research support the hypothesis that consciousness has a two-part structure: a focused region of articulated experience surrounded by a field of relatively unarticulated, vague experience.William James developed an especially useful phenomenological analysis of this "fringe" of consciousness, but its relation to, and potential value for, the study of cognition has not been explored. I propose strengthening James′ work on the fringe with a functional analysis: fringe experiences work to radically condense (...) context information in consciousness; are vague because a more explicit representation of context information would overwhelm consciousness′ limited articulation capacity; help mediate retrieval functions in consciousness; and contain a subset of monitoring and control experiences that cannot be elaborated in focal attention and are "ineffable." In general, the phenomenology of the fringe is a consequence of its cognitive functions, constrained by consciousness′ limited articulation capacity. Crucial to monitoring and control is the feeling of "rightness." Rightness functions as a summary index of cognitive integration, representing, in the fringe, the degree of positive fit between a given conscious content and its parallel, unconsciously encoded context. Rightness appears analogous to the connectionist metric of global network integration, known variously as goodness-of-fit, harmony, or minimum energy. (shrink)

If successive, brief visual images are exposed for recognition or for psychophysical ratings, various effects and phenomena of fast dynamics of conscious perception such as mutual masking, metacontrast, proactive enhancement of contrast, proactive speed-up of the latency of subjective visual experience, the Fröhlich Effect, the Tandem Effect, attentional facilitation by visuospatial precuing, and some others have been found. The theory proposed to deal with these phenomena proceeds from the assumption that two types of brain processes are necessary in order to (...) consciously recognize visual stimuli: fast, specific processes of encoding that allocate and reactivate the stimulus representation which is based on the activity of selected cortical neurons and relatively slower processes of facilitation of the activity of this specific representation that are mediated by the excitatory modulation of the EPSPs of those selected cortical neurons by the ascending input from nonspecific thalamus. Theperceptual retouchconstruct is proposed in order to characterize and analyze the interaction of and . The neurophysiological characteristics of this bifunctional system of afference help to put forward several predictions that are found to be consistent with the empirical regularities of the above-described perceptual-attentional phenomena. These data form a body of converging evidence that is consistent with the predictions of the perceptual retouch approach. (shrink)

1. My primary aim in this paper is to set the stage for a discussion of some of the central themes in the so-called "identity" approach to the mind-body problem. I have particularly in mind Herbert Feigl's elaborate statement and defense of this approach in Volume II of the Minnesota Studies. A secondary, but more constructive, purpose is to bring out some of the reasons which incline me to think that the theory is either very exciting but false, or true (...) but relatively uninteresting. (shrink)