Neuroscience and consciousness

The view in neuroscience today is that consciousness does not constitute a single, generalized process. It is becoming increasingly clear that consciousness involves a multitude of widely distributed specialized systems and disunited processes, the products of which are integrated in a dynamic manner by the interpreter module. Consciousness is an emergent property. From moment to moment, different modules or systems compete for attention and the winner emerges as the neural system underlying that moment’s conscious experience. Our conscious experience is assembled on the fly, as our b rains respond to constantly changing inputs, calculate potential courses of action, and execute responses like a streetwise kid.

So, here we are, back to the leading question of the chapter; How come we have that powerful almost self-evident feeling that we are unified when we are comprised of a gazillion modules? We do not experience a thousand chattering voices, but a unified experience. Consciousness flows easily and naturally from one moment to the next with a single unified, and coherent narrative. The psychological unite we experience emerges out of the specialized system called “the interpreter” that generates explanations about our perceptions, memories, and actions and the relationships among them. This leads to a personal narrative, the story that ties together all the disparate aspects of our conscious experience into a coherent whole: order from chaos. The interpreter module appears to be uniquely human and specialized to the left hemisphere. Its drive to generate hypotheses is a trigger for human beliefs, which, in turn, constrain our brain.

The constructive nature of our consciousness is not apparent to us. The action of an interpretive system becomes observable only when the system can be tricked into making obvious errors by forcing it to work with an impoverished set of inputs, most obviously in the split-brain or in lesion patients, but also in normal patients who have been fed faulty information. Even in the damaged brain, however, this system still lets us feel like “us”. We have learned from our split-brain patients that even when the left brain has lost all consciousness about the mental processes managed by the right brain and vice versa, the patient does not find one side of the brain missing the other. It is as if we don’t have knowledge about what we no longer have access to. The emergent conscious state arises out of separate mental systems, and if they are disconnected or damaged there is no underlying circuitry from which the emergent property arises.

Our subjective awareness arises out of our dominant left hemisphere’s unrelenting quest to explain these bits and pieces that have propped into consciousness. Notice that popped is in the past tense. This is a post hoc rationalization process. The interpreter that weaves our story only weaves with makes it into consciousness. Because consciousness is a slow process, whatever has made it to consciousness has already happened. It is a fait accompli. As we saw in my story at the beginning of chapter, I had already jumped before I realized whether I had seen a snake or if it was the wind rustling the grass. What does it mean that we build our theories about ourselves after the fact? How much of the time are we confabulating, giving a fictitious account of a past event, believing it to be true?

This post hoc interpreting process has implications for and an impact on the big question of free will and determinism, personal responsibility and our moral compass………. When thinking about these big question, one must always remember, remember, REMEMBER that all these modules are mental systems selected for over the course of evolution. The individuals who possessed them made choices that resulted in survival and reproduction. They became our ancestors. ~ Page 102 & 103

I have found that when I bring up the question of consciousness in a scientific context people are apt to make a great meal out of difficulties of defining it -- often with the intention of stopping what they see as a fruitless conversation ('if you can't even say what you are taking about, well.....). But surely these people must be playing some sort of intellectual game. They must know what consciousness is: what you lose under anaesthetic or when deeply asleep; what you regain more or less gradually as you wake up.....

Indeed it is difficult to find a crisp definition of consciousness, as it is difficult to fine one for, say, life. If by 'life' you mean life in all its detailed richness then this cannot be encompassed in a crisp definition. Yet (now) life can be understood as a product of evolution through natural selection. That provides us with a general definition, but of a kind that only became possible, because it could only make sense, after Lamarck, Darwin, Wallace and others had discovered evolution and started the lines that led to our current understanding of it. ~ Page 153 Excerpt: Evolving the Mind - Author A.G.Cairns-Smith

* We are not afraid to accept the notion of an uninterrupted sleep; on the other hand an eternal awakening (immorality, if it were conceivable, would be just that) plunges us into dread. Unconsciousness is a country, a fatherland; consciousness, an exile. ` Page 120 Excerpt "The Trouble With Being Born" ~ E. M. Cioran