Biology of Consciousness

Abstract

The Dynamic Core and Global Workspace hypotheses were independently put forward to provide mechanistic and biologically plausible accounts of how brains generate conscious mental content. The Dynamic Core proposes that reentrant neural activity in the thalamocortical system gives rise to conscious experience. Global Workspace reconciles the limited capacity of momentary conscious content with the vast repertoire of long-term memory. In this paper we show the close relationship between the two hypotheses. This relationship allows for a strictly biological account of phenomenal experience and subjectivity that is consistent with mounting experimental evidence. We examine the constraints on causal analyses of consciousness and suggest that there is now sufficient evidence to consider the design and construction of a conscious artifact.

Pathologies in functional connectivity, feedback control and robustness: a global workspace perspective on autism spectrum disorders

“…Thanks to significant developments in recent years, there is increasing recognition of this theory as a principal forerunner in the modeling of cognition and consciousness. Strongly supporting evidence for this model arises from a number of experimental studies such as those of Dehaene and Naccache (2001), Dehaene and Changeux (2005), Dehaene (2009), Gaillard et al (2009) that furthermore bring GWT into consonance with other leading theories embracing the neural correlates of consciousness (cf Edelman et al 2011;Freeman et al 2009;Kozma et al 2004). One aspect of the theory concerns how conscious perception is broadcasted widely across the human brain cortex to unconscious specialized processors (or 'unconscious cognitive modules') that continually undergo phase transitions, while breaking symmetry patterns within the network in question.…”

“…This type of network behavior reflects upon the 'biased competition' which is a notable factor 1 Recent findings Edelman et al (2011) reveal that a mechanism for GW can be provided by the 'Dynamic Core' hypothesis in terms of re-entrantly projecting neural signals throughout the brain cortex, such that a mental image, for instance, instantaneously activates a large number of cortical regions. Likewise, the spatio-temporal features of intra-cortical phase transitions is homologous to that of the broadcasting process in the GW (Freeman et al 2012;Shanahan 2010).…”

The Sound of Consciousness: Neural Underpinnings of Auditory Perception

“…It is actually not clear how any physical process, including neural activity, can give rise to a subjective phenomenon such as consciousness (Chalmers, 1996), but some promising empirical and theoretical headways have been made (Rees et al, 2002;Tononi, 2004;Tononi and Koch, 2008;Dehaene and Changeux, 2011;Edelman et al, 2011). The search for the NCC is thus an experimental subject that remains initially neutral on issues concerning causality, seeking instead to identify and characterize patterns of neural activity that specifically correlate with conscious experience and seeking to control for possible confounds using experimental designs that dissociate the contributions of consciousness from other (un)conscious cognitive functions (Frith et al, 1999).…”

Theories and methods in the scientific study of consciousness

“…The idea of a dynamic core is reminiscent of the earlier discussed global workspace. It has indeed been argued that the two theories may complement each other in such a way that the dynamic core essentially provides the neuronal substrate for the global workspace (Edelman, Gally, & Baars, 2011). Like GWT, the RDCT does not directly map upon the phenomenal/access distinction.…”