Consciousness plays an essential role in high-level cognition, which includes a long list of tasks such as perception, language comprehension, self-recognition, representation of other's mind, mental operations, complex reasoning and problem solving. Despite its importance, the of have not yet been revealed. Functional magnetic resonance imaging (fMRI) is an established technique for the study of neural correlates of consciousness (NCC) that involve high-level cognition by measuring cardiovascular responses. These works have indicated that the conscious mind emerges from the interaction of multiple neural networks. Among these networks, the working (executive) memory (WM) network coupled with the default mode network and dorsal attentional-network have been recently recognized to play a major role. We show evidences from cognitive social neuroscience experiments that indicate neural mechanisms supporting WM play a critical role in generating consciousness through executive functions such as updating, shifting and inhibiting incoming information. These executive works function in the dorsolateral and ventrolateral prefrontal cortex (PFC) and anterior cingulate cortex, with coordination across these and other brain areas being related to task dependent processes. WM's capacity limitation also plays a critical for active consciousness. Theoretical modeling of consciousness using graph theory, with which we can quantify large-scale networks of the brain, supports our WM-based consciousness. We propose a three-layered model of consciousness consisting of vigilance-, awareness-, and recursive-consciousness, which correspond to biological-, sensory-motor-, and self-consciousness, respectively. Among these layers, self-consciousness is likely critical for social interaction, which involves working together with other minds. Consistently, modular brain areas that bind multiple minds have been found in the medial PFC using fMRI. By introducing a false believe task, we confirmed high-level intentionality and meta-representation could also be involved in WM's executive function working on the dorsolateral PFC, which makes inference of another's mind possible.

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Despite the whirl of controversy surrounding consciousness studies, there is real progress being made in cognitive science towards establishing an empirically-rigorous theory of mind, in both its conscious and non-conscious manifestations. Beginning with a broad overview of clinical and experimental findings bearing on the neural correlates of conscious processes, the author traces the development of several related models that appear to converge upon a central “conscious system”. This extended reticular-thalamic activating system (ERTAS) has been increasingly implicated in a variety of functions associated with consciousness, including: orienting to salient events in the outer world; dream (REM) sleep; the polymodal integration of sensory processes in the cortex (binding); selective attention, and volition. It is argued that the increasing convergence of models from clinical and experimental neuroscience is leading towards a general theory of consciousness which is both non-dualist and non-reductionist.

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"Ko-ko-ro", meaning 'mind', is a complex higher order function of the human brain. The two distinct activities of mind that are best understood are the ability to recognize oneself, i.e., self-awareness, and the ability to read another mind. These two functions form the fundamental basis of humanity, thereby allowing us to conform and live in harmony within a given family, community, or society. The mind is formed under certain conditions within neural systems in the human brain, and potentially in some other primate brains. This activity is built upon the harmonic orchestration of various sub-components of mind formation, e.g., perception, sensing, cognition, learning and memory, emotion, consciousness, thoughts, desire, beliefs, and willingness. The current understanding of the mechanism of mind is limited, but growing evidence suggests that molecular, cellular, genetic, psychological, cognitive, and system neurobiological methods could help to further our knowledge of the mind. In this review, I will overview current understanding of the components of mind, particularly from a molecular neurobiological perspective, with anticipation that mapping the mind anatomically in molecular terms may ultimately be possible in the human brain.

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In the course of evolution, the most highly developed organ is likely the brain, which has become more complex over time and acquired diverse forms and functions in different species. In particular, mammals have developed complex and high-functioning brains, and it has been reported that several genes derived from retroviruses were involved in mammalian brain evolution, that is, generating the complexity of the nervous system. Especially, the sushi-ichi-related retrotransposon homolog (SIRH)/retrotransposon gag-like (RTL) genes have been suggested to play a role in the evolutionary processes shaping brain morphology and function in mammals. Genetic mutation and altered expression of genes are linked to neurological disorders, highlighting how the acquisition of virus-derived genes in mammals has both driven brain evolution and imposed a susceptibility to diseases. This review provides an overview of the functions, diversity, evolution and diseases associated with SIRH/RTL genes in the nervous system. The contribution of retroviruses to brain evolution is an important research topic in evolutionary biology and neuroscience, and further insights are expected to be gained through future studies.

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