What is the primary function of consciousness in the nervous system? The answer to this question remains enigmatic, not so much because of a lack of relevant data, but because of the lack of a conceptual framework with which to interpret the data. To this end, we have developed Passive Frame Theory, an internally coherent framework that, from an action-based perspective, synthesizes empirically supported hypotheses from diverse fields of investigation. The theory proposes that the primary function of consciousness is well-circumscribed, (...) serving the 'somatic nervous system[. For this system, consciousness serves as a frame that constrains and directs skeletal muscle output, thereby yielding adaptive behavior. The mechanism by which consciousness achieves this is more counterintuitive, passive, and “low level” than the kinds of functions that theorists have previously attributed to consciousness. Passive frame theory begins to illuminate (a) what consciousness contributes to nervous function, (b) how consciousness achieves this function, and (c) the neuroanatomical substrates of conscious processes. Our untraditional, action-based perspective focuses on olfaction instead of on vision and is 'descriptive' (describing the products of nature as they evolved to be) rather than 'normative' (construing processes in terms of how they should function). Passive frame theory begins to isolate the neuroanatomical, cognitive-mechanistic, and representational (e.g., conscious contents) processes associated with consciousness. (shrink)

This study tested the two main neurocognitive models of dreaming by using cognitive data elicited from REM sleep in normals and narcoleptics. The two models were the ''activation-only'' view which holds that, in the context of sleep, overall activation of the brain is sufficient for consciousness to proceed in the manner of dreaming (e.g., Antrobus, 1991; Foulkes, 1993; Vogel, 1978); and the Activation, Input source, Modulation (AIM model), which predicts that not only brain activation level but also neurochemical modulatory systems (...) exert widespread effects upon dreaming (Hobson & McCarley, 1977; Hobson, Pace-Schott, & Stickgold, 2000). Mental activity was studied in nocturnal REM in 15 narcoleptics and 9 normal healthy persons and in REM at the onset of daytime naps and nighttime sleep (SOREM) in narcoleptics. The study was performed in the subjects' homes, using instrumental awakenings and ambulatory polysomnographic techniques, and focused upon visual vividness, mentation report length, improbable and discontinuous bizarre features, and reflective consciousness. Within each subject group, most cognitive variables tended to fluctuate in line with expected variations in circadian activation level. When comparing the cognitive variables between the two groups, reflective consciousness was clearly highest in narcoleptics, whereas improbabilities and discontinuities were lower, with mentation report length and visual vividness differing less between the groups. These findings are consistent with the AIM model of sleep mentation, but not with the activation-only model. (shrink)

Hypnagogic and hypnopompic experiences (HHEs) accompanying sleep paralysis (SP) are often cited as sources of accounts of supernatural nocturnal assaults and paranormal experiences. Descriptions of such experiences are remarkably consistent across time and cultures and consistent also with known mechanisms of REM states. A three-factor structural model of HHEs based on their relations both to cultural narratives and REM neurophysiology is developed and tested with several large samples. One factor, labeled Intruder, consisting of sensed presence, fear, and auditory and visual (...) hallucinations, is conjectured to originate in a hypervigilant state initiated in the midbrain. Another factor, Incubus, comprising pressure on the chest, breathing difficulties, and pain, is attributed to effects of hyperpolarization of motoneurons on perceptions of respiration. These two factors have in common an implied alien ''other'' consistent with occult narratives identified in numerous contemporary and historical cultures. A third factor, labeled Unusual Bodily Experiences, consisting of floating/flying sensations, out-of-body experiences, and feelings of bliss, is related to physically impossible experiences generated by conflicts of endogenous and exogenous activation related to body position, orientation, and movement. Implications of this last factor for understanding of orientational primacy in self-consciousness are considered. Central features of the model developed here are consistent with recent work on hallucinations associated with hypnosis and schizophrenia. (shrink)

This is a bibliography of books and articles on consciousness in philosophy, cognitive science, and neuroscience over the last 30 years. There are three main sections, devoted to monographs, edited collections of papers, and articles. The first two of these sections are each divided into three subsections containing books in each of the main areas of research. The third section is divided into 12 subsections, with 10 subject headings for philosophical articles along with two additional subsections for articles in cognitive (...) science and neuroscience. Of course the division is somewhat arbitrary, but I hope that it makes the bibliography easier to use. This bibliography has first been compiled by Thomas Metzinger and David Chalmers to appear in print in two philosophical anthologies on conscious experience . From 1995 onwards it has been continuously updated by Thomas Metzinger, and now is freely available as a PDF-, RTF-, or HTML-file. This bibliography mainly attempts to cover the Anglo-Saxon and German debates, in a non-annotated, fully formatted way that makes it easy to "cut and paste" from the original file. To a certain degree this bibliography also contains items in other languages than English and German - all submissions in other languages are welcome. Last update of current version: July 13th, 2001. (shrink)

During sleep, consciousness is reduced, associated with a diminished connection of the brain to the environment. This is due to the blocking of the thalamocortical pathway by inhibitory mechanisms. This “thalamic gating” during sleep, however, is not complete, but partial. The stream of information is considerably reduced, but the brain is not fully disconnected from the environment. An inspection of the environment takes place to optimize safety during sleep. Stimuli having a meaning for the individual, or signaling danger, are recognized, (...) and may enter into awareness, leading to a wake-up call, which allows the individual to react. This subconscious stimulus evaluation is regarded as having a guardian function for sleep. The recognition of stimuli during sleep points toward the presence of a sort of consciousness without awareness in the sleeping brain. (shrink)