I studied philosophy and psychology at the University of Oxford from 1993 to 2000. My philosophical work was investigating the implications of the latest research in cognitive neuroscience and cognitive psychology, particularly connectionist modelling and dynamical systems theory. These areas are suggesting new ways of understanding the human mind, and most importantly, our conceptual capacities and the role of language. They are sensitive to the details of real neural processing, and thus can be considered to be 'neurally inspired'. This contrasts with (and is a direct reaction to) the more traditional field of artificial intelligence (AI) which explains cognitive operations in terms of syntactic mechanisms similar to those utilised by modern digital computers. The contrast is between an approach that posits static structures and one that posits dynamic self-organising systems.
The main thrust of my research was concerned with refuting a set of arguments put forward by Jerry Fodor et al. which contend that a connectionist approach could never properly account for important aspects of linguistic thought. Specifically, it is claimed that connectionism cannot provide an adequate account of the systematicity of thought. This term is used to indicate the interconnectedness of linguistic capacities. For example, if a person can think the thought that 'John loves Mary', they can also, as a matter of brute empirical fact, think the thought that 'Mary loves John'. One simply does not find individuals who can only think one of these. Fodor takes this to show that thought must have compositional structure, which is something that he thinks computational systems have, and connectionist systems do not.
In my work I took on board Fodor's criticisms of current connectionist explanations. However, my central claim was that connectionist models can be systematic if a new and more biologically plausible approach is taken. Part of this new approach is a novel kind of modularity - extending the work I did in my B.Phil. thesis on the increased computational power of multiple neural network models. Modularity is the idea that there are separate systems in the brain that have specific computational and functional roles. Fodor has argued that only input systems can be modular and that what he calls 'central processing' (for which read rational thought and other higher aspects of cognition) cannot be modular because of its special features. I think this is mistaken, and I argued that an altered notion of modularity, involving loose task specific coalitions of neural systems that constantly alter with context, can adequately explain 'central processing'. This approach can be modelled using many networks together, and not just single networks in isolation, as is currently the case in connectionist research. This interaction between multiple systems is exactly what is being found in the brain by cognitive neuroscientists. Brain imaging studies, for instance, reveal that even very simple linguistic tasks involve many brain areas, and which areas are active is dependent upon the exact details of the experimental task.
It is my hope that this research will lead to a new way of investigating and understanding the most interesting and essential aspects of human cognition, namely language and our ability to think about the world using it.
This is my major work to date, and deals with the philosophical implications of biological plausibility in connectionist network modelling. The first two chapters are an introduction to the essential ideas of connectionist and neural processing, and it is only in the third and last main chapter that it gets really interesting.
This thesis was part of my first degree (in Philosophy and Psychology) and was written when I was first discovering connectionism and its philosophical implications. It is not a great work, being written when I was a comparatively novice philosopher, but I am proud of the links it draws between Wittgenstein and modern cognitive science.
This paper investigates the consequences of analysing meaning in terms of recognitional capacities.
This paper examines Andy Clark's claim that language is an epistemic tool rather than the fundamental vehicle of thought.