What is Consciousness? Towards a Preliminary Definition

There is little or no general agreement about what researchers should focus on when studying consciousness. The most active scientific studies often use the methods of Cognitive Neuroscience and focus mainly on vision. Other aspects and contents of consciousness, namely thoughts and emotions, are much less studied, possibly leading to a biased view of what consciousness is and how it works. In this essay we describe what we call a referential nucleus, implicit in much of consciousness research. In this context, 'consciousness' refers to (partially) reportable content experienced by living individuals. We then discuss the philosophical concept of a phenomenal world and another contemporary view that conscious experience involves, besides integration of information in the brain, participation in action-perception cycles in a natural, social and cultural environment. These views imply a need to reconceptualize 'qualia' as the conscious aspect of subjective experiences, thus stating properties of consciousness that pose serious challenges to an exclusive approach via Cognitive Neuroscience, because experimental settings oversimplify conscious experiences, narrowing them to fragments correlated with measured brain activity and behaviour In conclusion we argue that a science of consciousness requires a broad interdisciplinary range of research, including qualitative methods from the Human Sciences.

N-methyl-D-aspartate channel and consciousness: From signal coincidence detection to quantum computing

Research on Blindsight, Neglect/Extinction and Phantom limb syndromes, as well as electrical measurements of mammalian brain activity, have suggested the dependence of vivid perception on both incoming sensory information at primary sensory cortex and reentrant information from associative cortex. Coherence between incoming and reentrant signals seems to be a necessary condition for (conscious) perception. General reticular activating system and local electrical synchronization are some of the tools used by the brain to establish coarse coherence at the sensory cortex, upon which biochemical processes are coordinated. Besides electrical synchrony and chemical modulation at the synapse, a central mechanism supporting such a coherence is the N-methyl-D-aspartate channel, working as a 'coincidence detector' for an incoming signal causing the depolarization necessary to remove Mg 2+, and reentrant information releasing the glutamate that finally prompts Ca 2+ entry. We propose that a signal transduction pathway activated by Ca 2+ entry into cortical neurons is in charge of triggering a quantum computational process that accelerates inter-neuronal communication, thus solving systemic conflict and supporting the unity of consciousness. © 2001 Elsevier Science Ltd.

Conceptual spaces and consciousness: Integrating cognitive and affective processes

In the book Conceptual Spaces: the Geometry of Thought [2000] Peter Gärdenfors proposes a new framework for cognitive science. Complementary to symbolic and subsymbolic [connectionist] descriptions, conceptual spaces are semantic structures constructed from empirical data representing the universe of mental states. We argue that Gärdenfors' modeling can be used in consciousness research to describe the phenomenal conscious world, its elements and their intrinsic relations. The conceptual space approach affords the construction of a universal state space of human consciousness, where all possible kinds of human conscious states could be mapped. Starting from this approach, we discuss the inclusion of feelings and emotions in conceptual spaces, and their relation to perceptual and cognitive states. Current debate on integration of affect/emotion and perception/cognition allows three possible descriptive alternatives: emotion resulting from basic cognition; cognition resulting from basic emotion, and both as relatively independent functions integrated by brain mechanisms. Finding a solution for this issue is an important step in any attempt of successful modeling of natural or artificial consciousness. After making a brief review of proposals in this area, we summarize the essentials of a new model of consciousness based on neuro-astroglial interactions. © 2011 World Scientific Publishing Company.

What affective neuroscience means for science of consciousness

The field of affective neuroscience has emerged from the efforts of Jaak Panksepp in the 1990s and reinforced by the work of, among others, Joseph LeDoux in the 2000s. It is based on the ideas that affective processes are supported by brain structures that appeared earlier in the phylogenetic scale (as the periaqueductal gray area), they run in parallel with cognitive processes, and can influence behaviour independently of cognitive judgements. This kind of approach contrasts with the hegemonic concept of conscious processing in cognitive neurosciences, which is based on the identification of brain circuits responsible for the processing of (cognitive) representations. Within cognitive neurosciences, the frontal lobes are assigned the role of coordinators in maintaining affective states and their emotional expressions under cognitive control. An intermediary view is the Damasio-Bechara Somatic Marker model, which puts cognition under partial somatic-affective control. We present here our efforts to make a synthesis of these views, by proposing the existence of two interacting brain circuits; the first one in charge of cognitive processes and the second mediating feelings about cognitive contents. The coupling of the two circuits promotes an endogenous feedback that supports conscious processes. Within this framework, we present the defence that detailed study of both affective and cognitive processes, their interactions, as well of their respective brain networks, is necessary for a science of consciousness.© MSM 2013.

A Commentary on de Sousa′s towards an Integrative Theory of Consciousness

De Sousa′s comprehensive two-part review of a diversity of contemporary approaches to the study of consciousness is highly welcome. He makes us aware of a proliferation of theoretical and empirical approaches targeting a common theme, but diverging in many ways. He skilfully accomplishes a classification of kinds of approach, identification of the main representatives, their contributions, and respective limitations. However, he does not show how the desired integration could be accomplished. Besides summarising de Sousa′s efficient analytical work, I make critical comments and briefly report my contribution for the integration project.© MSM 2013.

Hollows of a science of consciousness?

I consider Nixon’s essay a well thought discussion of the possibility of a genuine science of consciousness. Most of the sections are worth discussing, but to find the main message it may be necessary to read between the lines. The good news is that he does not present true impossibilities for this science, but his discussion leads to the (sound) conclusion that it would have to account for many unconscious factors that make us creative and human.

Rosa Luxemburg: marxismo e história

Ao interpretar o marxismo como unidade entre teoria e prática, Rosa Luxemburg lança os fundamentos da sua teoria da ação revolucionária, palavras com que poderíamos sintetizar o seu pensamento político, elaborado numa polêmica ininterrupta com o determinismo economicista da II Internacional.

Efeito do propofol associado à efedrina no tempo de latência do cisatracúrio

OBJETIVOS: Este estudo teve por objetivo avaliar a eficácia da efedrina na prevenção dos efeitos hemodinâmicos induzidos pela associação do propofol e do remifentanil, assim como os efeitos sobre o tempo de latência do cisatracúrio. MÉTODOS: Sessenta pacientes com idade entre 18 e 52 anos, estado físico ASA I ou II, foram divididos em três grupos, aleatoriamente: G I - propofol 1%; G II - propofol 1% + efedrina 0,5 mg.ml-1 e G III - propofol 1% + efedrina 1,0 mg.ml-1 (velocidade de infusão igual a 180 ml.h-1), até a perda da consciência. Administrou-se remifentanil (0,5 mg.kg-1.min-1) e cisatracúrio na dose de 0,15 mg.kg-1. Foram registrados os dados demográficos, os sinais vitais (PAS, PAM, PAD, FC e SpO2) e o tempo de latência do cisatracúrio. RESULTADOS: Os grupos foram homogêneos com relação aos dados demográficos. Houve diminuição estatisticamente significativa dos valores de PAS, PAM, PAD e FC, um e três minutos após a administração do propofol, porém sem significado clínico importante e sem diferença entre os grupos. As medianas para os tempos de latência do cisatracúrio foram: 178 s (G2 e G3) e 183 s (G1), mas sem diferença significante entre os grupos. CONCLUSÃO: Não houve diminuição clinicamente importante dos parâmetros hemodinâmicos avaliados nos grupos que receberam ou não a efedrina e o tempo de latência do cisatracúrio foi o mesmo para os diferentes grupos.

Patient perceptions about anesthesia and anesthesiologists before and after surgical procedures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Epidemiological and Serological Aspects in Canine Toxoplasmosis in Animals with Nervous Symptoms

The presence of anti-Toxoplasma gondii IgM and IgG antibodies was studied in samples of blood serum taken from eighty dogs with nervous symptoms at the Serviço de Enfermidades Infecciosas dos Animais, Faculdade de Medicina Veterinária e Zootecnia, Unesp, Botucatu, São Paulo, Brazil. The frequency of IgG titers were 16 (13.7%), 64 (13.7%), and 256 (5%), and for IgM titers were 16 (7.5%), 64 (15%), and 256 (8.7%). Positive reactions were more frequent in the older animals, males, from a rural environment, in constant contact with small animals, principally birds and rodents. There was a higher frequency of a positive reaction in dogs fed with kitchen food, especially in those fed with raw ingredients. The most common neurological pictures were alterations in consciousness, in movement, and in the hand-cart test. The percentage of reagents with specific IgM antibodies was high, indicating active infections, but the possibility of co-infection with the distemper virus can not be discarded, and this may be a predisposing factor for toxoplasmosis infection, once the distemper virus has a potent immunosupressive action.

Uma abordagem naturalista da consciência humana

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Do mito original ao mito ideológico: alguns percursos

Este artigo é parte de uma Dissertação de Mestrado - Mito e Paródia: sua estrutura e função no texto literário - defendida em novembro de 1983 no Instituto de Estudos da Linguagem/Unicamp. A passagem aqui reproduzida pertence ao capítulo que trata da conceituação do mito. Ela procura apreender alguns de seus aspectos básicos dinamicamente, na transição de sua forma original, tal como ocorre nas sociedades primitivas e arcaicas, para seu sucedâneo ideológico, no contexto das sociedades históricas.

Notas sobre a presença de Mead na obra de Habermas

Habermas pensa a questão da individuação e da socialização a partir dos estudos de George Hebert Mead, que, na sua concepção, foi o primeiro a refletir substancialmente sobre um modelo de eu produzido socialmente. Mead oferece todo subsídio teórico para o desenvolvimento de uma teoria da evolução humana que envolve o processo de individuação e de socialização. Pelo paradigma de intercompreensão, ou seja, da relação intersubjetiva de indivíduos que se socializam por meio da comunicação e se reconhecem mutuamente, Mead permite a mudança de paradigma da consciência de si, da autorreferência de um sujeito que age isoladamente para o indivíduo que processa trocas sociais mediante a linguagem. Portanto, um dos principais componentes da teoria de Mead, em que Habermas busca contribuição para sua Teoria da Ação Comunicativa, é o processo de constituição do eu, sua identidade. Mead acredita ser a individuação representada como um processo que é linguisticamente mediador da socialização e da construção de uma história de vida, na qual os sujeitos são conscientes de si. É esse meio linguístico estabelecido entre os sujeitos e o meio do entendimento intrassubjetivo e histórico vital que possibilita a formação de uma identidade de sujeitos socializados. É o reconhecimento intersubjetivo e autoentendimento mediado intersubjetivamente que propicia a formação da identidade. Esse quadro conceitual será fundamental a Habermas, na sua acepção de eu pós-convencional.