In the past many models of the mind have been constructed in an attempt to explain the phenomena of emotion, learning, perception and behaviour. None of them can however disregard the basic connection between the development of the hand and the brain. Freeing the hands by two-footedness made the brain able to grow. Without the use of hands there would have been no invention and manipulation of tools, no evolution of writing and consequently no information storage and tradition. It is important to realize that the brain belongs to the body. Without a body, it is unrealistic to state the existence of a mind.
During the 19th century, brain-models were dominated by analogies of mechanical, thermodynamic and even hydraulic processes. Most were dualistic, founded on the old Western thought that the body was a machine controlled by the brain, while the mind was separated from the body (and the brain). Between the world wars, electric brain metaphors like the telephone exchange were predominant.
Since the 1950s, most models have been associated with the sequential computer with its central processing unit. The brain-mind distinction got its metaphor in the hardware-software distinction. Theories concerning the mind become materialistic by stating that physical and chemical properties of the brain, together with pertinent processes were enough to explain the mechanisms of mind. Thus a material phenomenon, the brain, created the immaterial mind.
In the 1990s, the perspective has changed again and the parallel computer, programmed as a neural network is the most current metaphor for the working brain. This metaphor is often discussed in cybernetic terms as the brain uses both positive and negative feedback in managing, for example, sensorimotor control. Such duality is uncommon in most ordinary control systems, due to the risk of instabilities, but is combined highly successfully in the brain. Positive feedback is used in a feedforward control course to predict what happens next, while negative feedback makes small corrections within the movement.
Today, most biologists seems to take a materialistic, reductionist view of the phenomenon of the mind. Its existence is the emergent properties of chemical and physical processes from a sufficiently complex control system in a living organism. The material base consists of neurons, interacting with other neurons to a certain extent randomly. This interaction creates information patterns existing in a context beyond ordinary time and space. Therefore, most researchers agree upon a distributed mind, occupying the total area of the brain where all elements are of equal importance.
The view of a distributed mind can be extended further, to the whole of the organism. The brain is part of a nerve system existing everywhere in the body. Thus consciousness exists ubiquitously, although on many different levels, throughout the whole organism, suggesting an extension of the distributed-mind perspective.
Source: Skyttner Lars (2006), General Systems Theory: Problems, Perspectives, Practice, Wspc, 2nd Edition.