Two aspects of consciousness are first considered: consciousness as awareness (phenomenological meaning) and consciousness as strategic control (functional meaning). As to awareness, three types can be distinguished: first, awareness as the phenomenal experiences of objects and events; second, awareness as meta-awareness, i.e., the awareness of mental life itself; third, awareness as self-awareness, i.e., the awareness of being oneself. While phenomenal experience and self-awareness are usually present during dreaming (even if many modifications are possible), meta-awareness is usually absent (apart from some (...) particular experiences of self-reflectiveness) with the major exception of lucid dreaming. Consciousness as strategic control may also be present in dreams. The functioning of consciousness is then analyzed, following a cognitive model of dream production. In such a model, the dream is supposed to be the product of the interaction of three components: (a) the bottom-up activation of mnemonic elements coming from LTM systems, (b) interpretative and elaborative top-down processes, and (c) monitoring of phenomenal experience. A feedback circulation is activated among the components, where the top-down interpretative organization and the conscious monitoring of the oneiric scene elicitates other mnemonic contents, according to the requirements of the dream plot. This dream productive activity is submitted to unconscious and conscious processes. (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)

COMMENTARY ON: LaBerge, D.. Attention, awareness, and the triangular circuit. Consciousness and Cognition, 6, 149-181. ABSTRACT: LaBerge proposes that underlying attention and self-awareness is a triangular circuit involving interconnected posterior cortical, thalamic and prefrontal neural ensembles. While the target paper makes only passing reference to it, the reticular nucleus of the thalamus is an integral part of the triangular circuit he posits. Indeed, it is essential to a complete understanding of his model.