Dopamine plays a key role in consciousness

Summary of the findings from the cited paper [1]:

> Understanding the neural bases of consciousness is of basic scientific and clinical importance. Human neuroimaging has established that a network of interconnected brain regions known as the default mode network disintegrates in anesthesia and after brain damage that causes disorders of consciousness. However, the neurochemical underpinnings of this network change remain largely unknown. [1]

> Motivated by preclinical animal work and clinical observations, we found that across pharmacological (sedation) and pathological (disorders of consciousness) consciousness perturbation, the dopaminergic source nucleus, the ventral tegmental area, disconnects from the main nodes of the default mode network. As the severity of this dopaminergic disconnection was associated with default mode network disintegration, we propose that dopaminergic modulation may be a central mechanism for consciousness maintenance. [1]

One of the more startling facts presented in OP:

> In a landmark study in 2006, a team of researchers showed that a 23-year-old woman, who suffered severe brain trauma and was thought to be in a vegetative state following a traffic accident, had signs of awareness. The patient was asked to imagine playing tennis during a brain scan (fMRI) and the scientists saw that regions of the brain involved in motor processes activated in response. [...] The pattern of activation that she showed was similar to that of healthy people, and she was deemed to have awareness even though that wasn’t noticeable in classical clinical assessment (not involving brain scans).

> This year, a group of scientists, writing in the journal Brain, warned that one in five patients in vegetative states may in fact be conscious enough to follow commands during brain scans – though there is no consensus on this. (see cited publication [2])

Understanding the correlation between dopamine and consciousness is an incremental but important step forward. Still, we are desperately in need of a true theory of consciousness that offers unification with physical laws of nature.

Orchestrated objective reduction is one such theory of consciousness [3]. Here's a quick summary of 'Orch OR':

> The Orch OR theory proposes quantum computations in brain microtubules account for consciousness.

> Microtubule ‘quantum channels’ in which anesthetics erase consciousness are identified.

> Evidence for warm quantum vibrations in brain microtubules is cited.

> Interference of microtubule vibrations are ‘beat frequencies’ seen as EEG.

> Orch OR links consciousness to processes in fundamental space–time geometry.

[1] Dopaminergic brainstem disconnection is common to pharmacological and pathological consciousness perturbation https://www.pnas.org/content/pnas/118/30/e2026289118.full.pd...

[2] Prolonged disorders of consciousness: a critical evaluation of the new UK guidelines https://academic.oup.com/brain/article-abstract/144/6/1655/6...

[3] Consciousness in the universe: a review of the 'Orch OR' theory https://pubmed.ncbi.nlm.nih.gov/24070914/