Bridging the Gap between Animal Brains and “Intelligent” Human Brains.

In drafting The Evolution of Intelligence – From Neural Nets to Language I was perhaps trying to get a quart into a pint pot – as I had a lot that I wanted to say which could not reasonably all fit into one post. First reactions show that I failed to clearly state how the whole fitted into an evolutionary model. So here goes ...

Basic Evolutionary Principles

• All land vertebrates have basically the same body architecture
• Some mammals have made extreme modifications to the basic architecture simply by stretching some bits and/or shrinking others.
• To understand the changes in a particular case we need to understand

1. the original organ that has been stretched
2. The way it has been stretched
3. the evolutionary pressures on it to expand or not
4. Any special adaptations or trigger points necessary to explain the extreme stretching.

The Key Question

• In the Human species something has expanded in the brain apart from its physical size. What is it and what factors would have been relevant in its expansion?

My Suggested Answer in General Terms

1. All land vertebrate brains need to have a simple “trial and error” mechanism for classifying relevant features of their environment, remembering the past, and using these memories to suggest appropriate actions. This should include an accelerated ability to learn about dangers.
2. This basic mechanism, with a few comparatively small modifications, is sufficient to explain what the human brain does given the right resources in term of physical brain size and time to learn. In behavioural terms most of what we actually see is cultural and need not represent any major changes in the brain's internal way of working.
3. While it might seem obvious that being more intelligent is an evolutionary advantage in practice this is not the case. This is because a large brain is an expensive organ to run, the “learning” process is slow, and everything learnt is lost when the brain dies. Species which use their limited resources on other ways of staying alive are more likely to be successful.
4. The more information that can be transferred from one generation to the next the more economic it becomes to expand the brain's information holding capacity. There are a number of potential trigger points where improving such communication significantly increases the advantage of being able to store and process more information. One such trigger point is undoubtedly the ability to name objects and actions by associating symbolic noises and/or gestures with them. Another could be the modification of the “learn about dangers quickly” mechanism that must be present in all animal brains to apply to information transferred from older members of the species.

My Specific Contribution to answering the Key Question

There has been much debate in the literature as to the validity or not of such models. My specific contribution to the debate is to show that a highly unconventional artificial language called CODIL can demonstrate significant information processing capabilities AND appears to be compatible with the very simple information processing model which all land vertebrates must have to some degree. I do not claim CODIL provides a perfect model of how the brain processes information, or the steps needed to get to where we are today. However it demonstrates possible mechanisms by which a basic animal brain could be stretched to support something approaching natural language and human intelligence.

If your reaction is to reject the CODIL approach because it was a byproduct of computer modelling I suggest you look at How many trucks will your helicopter pull?