http://precedings.nature.com/tags/Consciousness Recently posted documents tagged with 'Consciousness' Nature Publishing Group en Nature Precedings http://precedings.nature.com/images/header_logo.gif http://precedings.nature.com http://dx.doi.org/10.1038/npre.2009.2444.2 At the phenomenal level, consciousness can be described as a singular, unified field of recursive self-awareness, consistently coherent in a particular way; that of a subject located both spatially and temporally in an egocentrically-extended domain, such that conscious self-awareness is explicitly characterized by I-ness, now-ness and here-ness. The psychological mechanism underwriting this spatiotemporal self-locatedness and its recursive processing style involves an evolutionary elaboration of the basic orientative reference frame which consistently structures ongoing spatiotemporal self-location computations as i-here-now. Cognition computes action-output in the midst of ongoing movement, and consequently requires a constant self-locating spatiotemporal reference frame as basis for these computations. Over time, constant evolutionary pressures for energy efficiency have encouraged both the proliferation of anticipative feedforward processing mechansims, and the elaboration, at the apex of the sensorimotor processing hierarchy, of self-activating, highly attenuated recursively-feedforward circuitry processing the basic orientational schema independent of external action output. As the primary reference frame of active waking cognition, this recursive i-here-now processing generates a zone of subjective self-awareness in terms of which it feels like something to be oneself here and now. This is consciousness. http://dx.doi.org/10.1038/npre.2009.2444.2 Fri, 23 Oct 2009 19:55:37 UTC Consciousness as Recursive, Spatiotemporal Self-Location doi:10.1038/npre.2009.2444.2 2009-10-23 Frederic Peters Nature Precedings 2009-10-23T19:55:37Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/2465/version/1 Abstract: The nature and physical basis of consciousness remains the central enigma of the scientific description of reality in the third millennium. This paper seeks to examine the phenomenal nature of subjective consciousness and elucidate a possible biophysical basis for its existence, in terms of a form of quantum anticipation based on entangled states driven by chaotic sensitivity of global brain dynamics during decision-making processes. Evidence is presented for the evolutionary emergence of chaotic excitation as a universal sense organ in the founding eucaryotes, which then became used in a context-sensitive manner by complex central nervous systems, leading to the dynamical brain. http://precedings.nature.com/documents/2465/version/1 Wed, 05 Nov 2008 16:06:56 UTC The Central Enigma of Consciousness hdl:10101/npre.2008.2465.1 2008-11-05 Chris C. King Nature Precedings 2008-11-05T16:06:56Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/2444/version/1 At the phenomenal level, consciousness can be described as a singular, unified field of recursive self-awareness, consistently coherent in a particular way; that of a subject located both spatially and temporally in an egocentrically-extended domain, such that conscious self-awareness is explicitly characterized by I-ness, now-ness and here-ness. The psychological mechanism underwriting this spatiotemporal self-locatedness and its recursive processing style involves an evolutionary elaboration of the basic orientative reference frame which consistently structures ongoing spatiotemporal self-location computations as i-here-now. Cognition computes action-output in the midst of ongoing movement, and consequently requires a constant self-locating spatiotemporal reference frame as basis for these computations. Over time, constant evolutionary pressures for energy efficiency have encouraged both the proliferation of anticipative feedforward processing mechansims, and the elaboration, at the apex of the sensorimotor processing hierarchy, of self-activating, highly attenuated recursively-feedforward circuitry processing the basic orientational schema independent of external action output. As the primary reference frame of active waking cognition, this recursive i-here-now processing generates a zone of subjective self-awareness in terms of which it feels like something to be oneself here and now. This is consciousness. http://precedings.nature.com/documents/2444/version/1 Fri, 31 Oct 2008 13:27:48 UTC Consciousness as Recursive, Spatiotemporal Self-Location hdl:10101/npre.2008.2444.1 2008-10-31 Frederic Peters Nature Precedings 2008-10-31T13:27:48Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/2272/version/1 The investigation of subjective experiences (SEs) of space and time is at the core of consciousness research. The term ‘space’ includes the subject and objects. The SE of subject, I-ness, is defined as ‘Self’. The SEs of objects, subject’s external body, and subject’s internal states such as feelings, thoughts, and so on can be investigated using the proto-experience (PE)-SE framework. The SE of time is defined as ‘phenomenal time’ (which includes past, present and future) and the SE of space as ‘phenomenal space’. The three non-experiential materialistic models are as follows: (I) The quantum-dissipation model [25] can connect the discrete neural signals to classical electromagnetic field to ‘quantum field theory and chaos theory’ for explaining memory. (II) The soliton-catalytic model [8] hypothesizes that all living processes including micro- and macro-processes can be explained by catalysis process. (III) The ‘sensation from evolution of action’ model [13] proposes that SEs are internalized during evolution. All these models can address to some extent the function of structures, such as perception. They cannot address explanatory gap. The complementary experiential PE-SE framework [37] addresses this psycho-physical gap and elucidates the SEs of space and time. http://precedings.nature.com/documents/2272/version/1 Wed, 10 Sep 2008 09:59:46 UTC Subjective Experiences of Space and Time: Self, Sensation, and Phenomenal Time hdl:10101/npre.2008.2272.1 2008-09-10 Ram Lakhan Pandey Vimal Nature Precedings 2008-09-10T09:59:46Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/2246/version/1 When an image is presented to one eye and a very different image is presented to the corresponding location of the other eye, they compete for conscious representation, such that only one image is visible at a time while the other is suppressed. Called binocular rivalry, this phenomenon and its deviants have been extensively exploited to study the mechanism and neural correlates of consciousness. In this paper, we propose a framework, the unconscious binding hypothesis, to distinguish unconscious processing from conscious processing. According to this framework, the unconscious mind not only encodes individual features but also temporally binds distributed features to give rise to cortical representation, but unlike conscious binding, such unconscious binding is fragile. Under this framework, we review evidence from psychophysical and neuroimaging studies, which suggests that: (1) for invisible low level features, prolonged exposure to visual pattern and simple translational motion can alter the appearance of subsequent visible features (i.e. adaptation); for invisible high level features, although complex spiral motion cannot produce adaptation, nor can objects/words enhance subsequent processing of related stimuli (i.e. priming), images of tools can nevertheless activate the dorsal pathway; and (2) although invisible central cues cannot orient attention, invisible erotic pictures in the periphery can nevertheless guide attention, likely through emotional arousal; reciprocally, the processing of invisible information can be modulated by attention at perceptual and neural levels. http://precedings.nature.com/documents/2246/version/1 Tue, 02 Sep 2008 18:55:51 UTC Seeing the invisible: The scope and limits of unconscious processing in binocular rivalry hdl:10101/npre.2008.2246.1 2008-09-02 Zhicheng Lin Nature Precedings 2008-09-02T18:55:51Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1473/version/1 Recent research into whole genome mapping of the mouse brain has made possible direct investigation of the brain expression of unusual genes. A search of the Allen Brain Atlas database has provided genetic and neuro-anatomical evidence for widespread specific expression in the brain of eight genes specific to sensory transduction, in vision, hearing and touch. A novel biophysical model is proposed for the function of these proteins, in generating the internal model of experiential reality. http://precedings.nature.com/documents/1473/version/1 Tue, 01 Jan 2008 23:35:34 UTC Sensory Transduction and Subjective Experience: Expression of eight genes in three senses suggests a radical model of consciousness hdl:10101/npre.2007.1473.1 2008-01-01 Chris C. King Nature Precedings 2008-01-01T23:35:34Z Manuscript Genetics & Genomics Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1368/version/1 Hallucinogenic plants are often regarded as the main source of psychoactive drugs in antiquity to reach deep altered states of consciousness1,2. Many researchers believe this was particularly true during the Tiwanaku empire expansion, circa (500-1000 A.D.), along the Atacama Desert of Chile. Highly decorated snuffing tablets and tubes are often found as grave goods during this period3,4,5,6,7,8. Until now the type of drugs consumed in this paraphernalia has been unclear. From the modern city of Arica, naturally mummified human bodies with abundant hair provided a unique opportunity to test for hallucinogenic plants consumed in Andean prehistory. Analysis by gas chromatography and mass spectrometry demonstrated the presence of harmine. The Banisteriopsis vine, commonly called Ayahuasca, was the probable source. This is the first confirmed evidence of psychoactive plant consumption in pre-Hispanic Andean populations along the Atacama coastal region. Of the 32 mummy hair samples analyzed 3 males tested positive for harmine. This alkaloid aids in the catalysis and synergic effects of powerful hallucinogenic drugs. The consumption of harmine was likely related to medicinal practices and not exclusively ingested by shamans. Another important aspect of this evidence is that Banisteriopsis is an Amazon plant. It does not grow in the Atacama coastal region. Thus, our findings reveal extensive plant trade networks in antiquity between the coast, desert, highlands, and Amazon basin. The excellent preservation of human organic specimens, the use of gas chromatography and mass spectrometry allowed us to map and demonstrate the consumption of psychoactive compound plants in Andean prehistory. In addition, our findings open the door for future studies to debate the consumption and social role of ancient psychoactive and hallucinogenic plants. http://precedings.nature.com/documents/1368/version/1 Mon, 03 Dec 2007 10:58:56 UTC Prehistoric psychotropic consumption in Andean Chilean mummies hdl:10101/npre.2007.1368.1 2009-01-13 Juan P. Ogalde Nature Precedings 2007-12-03T10:58:56Z Manuscript Chemistry Pharmacology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1244/version/1 As pointed out by William James, “the consciousness is a dynamic process, not a thing” , during which short term integration is succeeded by another differentiated neural state through the continual interplay between the environment, the body, and the brain itself. Thus, the dynamic structure underlying successive states of the brain is important for understanding human consciousness as a process. In order to investigate the dynamic property of human consciousness, we developed a new method to reconstruct a state space from electroencephalogram(EEG), in which a trajectory, reflecting states of consciousness, is constructed based on the global information integration of the brain. EEGs were obtained from 14 subjects received an intravenous bolus of propopol. Here we show that the degree of human consciousness is directly associated with the information integration capacity of gamma wave, which is significantly higher in the conscious state than in the unconscious state. And we found a new time evolutional property of human consciousness. The conscious state showed a lower dimensional dynamic process which changed to a random-like process after loss of consciousness. This characteristic dynamic property, appeared only in the gamma band, might be used as an indicator to distinguish the conscious and unconscious states and also considered as an important fact for the human consciousness model. http://precedings.nature.com/documents/1244/version/1 Wed, 24 Oct 2007 16:33:49 UTC A new dynamic property of human consciousness hdl:10101/npre.2007.1244.1 2008-04-22 UnCheol Lee Nature Precedings 2007-10-24T16:33:49Z Manuscript Neuroscience http://creativecommons.org/licenses/by/2.5/ http://precedings.nature.com/documents/760/version/1 Conscious perceptual processing involves the sequential activation of cortical networks at several brain locations, and the onset of oscillatory synchrony affecting the same neuronal population. How do the earlier activated circuits sustain their excitation to synchronize with the later ones? We call such a sustaining process “meta-potentiation”, and propose that it depends on neuro-astroglial interactions. In our proposed model, attentional cholinergic and stimulus-related glutamatergic inputs to astroglia elicit the release of astroglial glutamate to bind with neuronal NMDA receptors containing the NR2B subunit. Once calcium channels are open, slow inward currents activate the CaM/CaMKII complex to phosphorylate AMPA receptors in a population of neurons connected with the astrocyte, thus amplifying the local excitatory pattern to participate in a larger synchronized assembly that supports consciousness. http://precedings.nature.com/documents/760/version/1 Mon, 20 Aug 2007 17:14:04 UTC Meta-Potentiation: Neuro-Astroglial Interactions Supporting Perceptual Consciousness hdl:10101/npre.2007.760.1 2007-08-20 Alfredo Pereira Jr Nature Precedings 2007-08-20T17:14:04Z Manuscript Neuroscience http://creativecommons.org/licenses/by/2.5/