From cells to sensations: A window to the physics of mind

Mind-brain identity theory confirmed?

Presented here is a novel graphical, structural, and functional model of the embodied mind. Despite strictly adhering to a physicalistic and reductionist approach, this model successfully resolves the apparent contradiction between the thesis regarding the causal closure of the physical realm and the widely held common-sense belief that the mental realm can influence physical behavior. Furthermore, it substantiates the theory of mind-brain identity while shedding light on its neural foundation. Consciousness, viewed as an epiphenomenon in certain respects, simultaneously possesses causal potency. These two aspects operate concurrently through distinct brain processes. Within the paper, particular emphasis is placed on the significance of qualia and emotions, accompanied by an explanation of their phenomenal nature grounded in the perceptual theory of emotions. The proposed model elucidates how autonomous agents can deliberate on various action scenarios and consciously select the most optimal ones for themselves, considering their knowledge of the world, motivations, preferences, and emotions.

Framework for internal sensation of pleasure using constraints from disparate findings in nucleus accumbens

It is necessary to find a mechanism that generates first-person inner sensation of pleasure to understand what causes addiction and associated behaviour by drugs of abuse. The actual mechanism is expected to explain several disparate findings in nucleus accumbens (NAc), a brain region associated with pleasure, in an interconnected manner. Previously, it was possible to derive a mechanism for natural learning and explain: (1) Generation of inner sensation of memory using changes generated by learning; and (2) Long-term potentiation as an experimental delayed scaled-up change by the same mechanism that occur during natural learning. By extending these findings and by using disparate third person observations in NAc from several studies, present work provides a framework of a mechanism that generates internal sensation of pleasure that can provide interconnected explanations for: (1) Ability to induce robust long-term depression (LTD) in NAc from naïve animals; (2) Impaired ability to induce LTD in “addicted” state; (3) Attenuation of postsynaptic potentials by cocaine; and (4) Reduced firing of medium spiny neurons in response to cocaine or dopamine. Findings made by this work are testable.