Why do we act the way we do ? Each individual on this planet is distinguished by his or her distinctive neural pathways, every single person has a different connection of the thousands possible. The response time, and in some individuals even the neurotransmitter used is completely different. The fact that the brain is compartmentalised gives rise to even more possible places where the brain may secrete away the answers to what truly constitutes behaviour.

Each part of the brain houses a different function, or the interconnecting link to some function. This is extremely important because it allows us to explain the brain as behaviour by making more functions located in the central nervous system. Within ourselves we divide the brain not only into physical regions but imaginary regions such as the mind, soul, etc these divisions allow us to explain our behaviour as either conscious or unconscious, deliberate or instinct. We compartmentalise our explanations as much as we assign different functions to the different regions of the brain.

The impulses for behaviour are as varied as the neural connections within us. We are a series of layers - from the simple inner layer that governs our unconscious, homeostatic functions, eg peristalsis, to our neocortex which allows us to reason and think about such abstract concepts as emotion and beauty and respond to them in a certain manner. Thus the layers and compartments of the brain merely emphasise the idea that the brain is behaviour.

Currently we are at a very elevated stage of evolutionary development. We have experimented with various behaviours and kept those that we find useful and discard those that are less beneficial. Mother Nature is constantly experimenting with certain behaviours to see which will further our race. In conjunction with these experiments different parts of our brains have been employed to comply with these necessary behaviours. Temperature regulation, for example, is mostly regulated by the most ancient part of our brain, the inner layer, whereas our mating rituals, in our more complex world have fortunately been taken over, in most individuals, by the neocortex: we reason and court rather than just take. Thus the different regions and connections that we learn from experience, be it evolutionary or individual, are compartmentalised in the brain in conjunction with the behaviour that it houses.

An interesting and productive way to think about it. Have read Paul McLean's The Triune Brain, Luria's Higher Cortical Function in Man?, Shallice's From Neuropsychology to Mental Structure? Yes, of course, the boxes (compartments) have evolutionary origins, and there is certainly some hierarchy to them. At the same time, one wants need to be too literal either in identifying boxes with behaviors or giving an adaptionist twist to every behavior. Evolution is constantly playing with variant forms, for no reason other than to play with them ... and most behavior results from interaction of boxes at multiple levels. Or, at least, I think that's what we'll find as we talk more about it. PG