How we might be able to
understand the brain
Brian D. Josephson
Department of Physics
University of Cambridge
Cambridge, UK
http://www.tcm.phy.cam.ac.uk/~bdj10
1. Introduction
Current neuroscience deals with relationships between brain and behaviour in a piecemeal manner, using
experiment or computer modelling to relate specific neural circuits to specific cognitive functions. While much
detailed information concerning basic cognitive functions has been gained in this way, these achievements throw
little light on more complex capacities such as those involving language, which involve a number of
comparatively elementary processes working together in a coordinated way that is hard to understand in terms of
information gained from the usual kinds of experiment or computer-simulation based models. Such approaches
find themselves in a situation similar to trying to understand the workings of a complicated computer program
without knowing the source code that describes the logical structure underlying the program s behaviour.
The essence of the problem is that the brain, as normally conceived, is a system whose behaviour is in practical
terms unanalysable except in comparatively simple cases. It might be said that in the nervous system case it is
difficult to see the trees (the logically significant forms) for the wood (the complicated totality): a number of
such trees have been discovered, but we are not very clear what they look like and are confused by the
complexity. The case of linguistic processes is of interest since here much is understood, on the basis of
linguistic studies, concerning the logic, but at the level of the phenomena only. Such descriptive understanding
is largely divorced from an understanding of the underlying mechanisms; linguists focus on modelling the
phenomena and ignore the neural mechanisms, whilst conversely neuroscientists treat language essentially as a
phenomenon manifesting in particular neural networks, and take little account of the details of linguistic
theories.
This paper addresses these problems on the basis of a new foundation, involving a specific set of hypotheses as
to the basic form and logic of the nervous system design. The concepts on which these hypotheses are based
include the hyperstructure concept of Baas (1994), the dependence of design on models and abstractions
(Josephson 2002), and representational redescription (Karmiloff-Smith 1992). In the following, it is shown
how putting these ideas together leads to an explanation in principle of how cognitive abilities such as those
associated with language can arise from a structure such as that of the nervous system. In contrast to other
approaches, the specifications associated with the present approach are sufficiently constrained by the phenomena
to be understood that (assuming the correctness of the basic concepts of the proposed scheme) one can envisage
the details being discovered over time through a combination of experiment and analysis, just as details are
discovered for other biological processes, leading to a full account of the processes underlying linguistic and
other advanced cognitive skills.