Brain Versus Machine

Abstract

Many biologists, especially those who study the biochemistry or cell biology of neural tissue are sceptical about claims to build a human brain on a computer. They know from first hand how complicated living tissue is and how much there is that we still do not know. Most importantly a biologist recognizes that a real brain acquires its functions and capabilities through a long period of development. During this time molecules, connections, and large scale features of anatomy are modified and refined according to the person’s environment. No present-day simulation approaches anything like the complexity of a real brain, or provides the opportunity for this to be reshaped over a long period of development. This is not to deny that machines can achieve wonders: they can perform almost any physical or mental task that we set them—faster and with greater accuracy than we can ourselves. However, in practice present day intelligent machines still fall behind biological brains in a variety of tasks, such as those requiring flexible interactions with the surrounding world and the performance of multiple tasks concurrently. No one yet has any idea how to introduce sentience or self-awareness into a machine. Overcoming these deficits may require novel forms of hardware that mimic more closely the cellular machinery found in the brain as well as developmental procedures that resemble the process of natural selection.