consciousness evolved

Edelman, Gally and Baars have published a review article detailing how they see the current state of consciousness research. One (and only one of many) interesting aspects of this review is the way they treat selection as a mechanism. First here is their 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 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 analysis of consciousness and suggest that there is now sufficient evidence to consider the design and construction of a conscious artifact.

The brain has a great deal of plasticity which is important to learning, action and consciousness. The authors present three levels as a theory of Neural Darwinism:

(1) Developmental selection – During the development of the brain, neurons that fire together wire together. While there are a number of genetic constraints on the formation of brain circuits, a number of epigenetic processes leads to extensive individual variance. These circuits constitute a primary repertoire for further selection.

(2) Experiential selection – During development and after the formation of variant neuroanatomy, changes in synaptic strength result in the further selection of variant neuronal groups that is characteristic of individual experience, constituting a secondary repertoire. The distribution and magnitude of these changes are constrained by inborn value systems, a diverse set of neural circuits producing various neuromodulators selected over evolutionary time.

(3) Reentry – Long-range, reciprocal, and massively parallel connections from one brain area to another provide the dynamic spatiotemporal coordination in circuits of groups that is necessary for integrated and adaptive conscious behavior.

The brain’s structures were selected for during evolution to function in the planning of adaptive behaviour in complex and changing environments. In order words, the organism is embedded in the environment and its brain is embodied in the organism. The body and brain must work in an environment that is dynamic and ambiguous, and they must remain coordinated.

According to Neural Darwinism, qualia reflect higher-order discriminations entailed by the workings of the Dynamic Core. … It should be added that consciousness itself is not causal. It is the neural structures underlying conscious experience that are causal. The conscious individual can therefore be described as responding to a causal illusion, one that is an entailed evolutionary outcome of selection for animals able to make plans involving multiple discriminations.

Isn’t it nice to have people keeping their eye on the plot? Organisms have become as we find them through evolution. That has to include consciousness.

Edelman, G., Gally, J., & Baars, B. (2011). Biology of Consciousness Frontiers in Psychology, 2 DOI: 10.3389/fpsyg.2011.00004

2 thoughts on “consciousness evolved

  1. Hi Janet

    How do I get to the other part of your web site now so that I can see your messages and see the pictures of your house?

    JK: Judith, I have sent you a regular email with information. You can get to here from the other site but not from here to the other. Janet

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