The Ancestry of Reason
This mysterious thing we call consciousness – our sensations, emotions, our capacity for abstract reason – can it really be explained in purely material terms as the product of a huge assemblage of nerve-cells? The answer seems to be a firm yes. In recent years neuroscientists have discovered a good deal about how the complex circuitry of the brain creates consciousness. It’s become clear that this circuitry has evolved in conjunction with an ever-increasing number and variety of sensory receptors. It provides a form of memory which puts multiple assorted sensory inputs together, allowing significant conjunctions and correlations to be discovered, even among inputs which have not occurred simultaneously. And unlike older forms of memory it can record patterns of input which have no apparent significance for survival.
In this form of memory the store of information can be accessed in a way that makes it possible to choose between potential actions. Instead of merely reacting to current inputs, guided perhaps by Pavlovian conditioning, a conscious animal can make choices and plans – can decide, for instance, to journey to a distant, remembered goal. Naylor suggests that finding a way around the local environment was the activity in which consciousness was first applied. Since most environments vary too much for more than a very rough form of guidance to be passed on in the genes this is where it would be most valuable. In some species consciousness would be gradually expanded, to guide other forms of action. In humans the brain’s capacity for correlating assorted evidence has grown to a degree that makes abstract ideas and abstract reason possible.
The elaborate nerve-systems that produce consciousness constitute a substantial investment. They take time to grow, need a lot of food, and above all need to be educated. Big brains have consequently evolved with a built-in urge to use them, and a capacity to gain reward from doing so. This gives us a means of deducing where consciousness is present in other animals.
The aim in this book has been to produce a digest of the most pertinent discoveries of neuroscience, one that will be accessible to anyone who is seriously interested in these questions, regardless of their scientific background or lack of it. For those whose scientific education was scanty, or is now forgotten or out of date, there are brief introductions to relevant disciplines.
Might be interested? Try some sample chapters.Chapter 2 Reason and Consciousness 7 Learning to See 8 Creating the Conscious Visual Moment 9 The Benefits of Conscious Sensory Experience 11 Subtler Forms of Reinforcement - Cognitive Emotions 25 Overview 27 A Tentative History of Consciousness
It would have been nice to include a really comprehensive bibliography in the book, but there was only room for the mare essential stuff.
However, for readers who want to explore any of the subjects covered further an extension to the bibliography is available here.