Christopher D. Green
Theoretical Psychology Research Projects

My main current theoretical research has been an investigation of whether, and in what sense, connectionist networks can be said to constitute models or theories of cognitive processes. An early statement of this work can be found in "Are Connectionist Models Theories of Cognition?" (Psycoloquy 1998, 9, 4). It is accompanied by over a dozen commentaries and an equal number of replies. In a more highly-developed article entitled "Scientific models, connectionist networks, and cognitive science" (Theory & Psychology, 2001, 11, 97-117) I re-examined the question in light of recent work in philosophy of science on the question of what role models play in science more generally. I have just completed, at the University of Toronto, a doctoral dissertation entitled (How) Do Connectionist Networks Model Cognition which explores the matter in even greater depth.

The work on whether connectionist models count as theories grew out of a more general project in which I was examining the sense in which computational models of cognition -- particularly connectionist models -- can be said to explain cognitive processes. Traditional theories of explanation have relied heavily on the notion of causation (viz., to explain x is to give the cause of x), or on inference (viz., to explain x. is to give an argument that implies x). Paul Smolensky (1995) has argued that the connectionist level of description gives the causes of cognition, but not the explanation; that only the symbolic (i.e. folk-psychological) level of description explains cognition. Some eliminativists (e.g. Ramsey, Stich & Garon, 1991) have argued, however, that acceptance of the connectionist level of description entails a commitment to the elimination of the folk-psychological vocabulary (e.g. belief, desire) from scientific psychology.

In "What kind of explanation, if any, is a connectionist net?" (In C.W. Tolman, et al. (Eds.), Problems of theoretical psychology, Captus, 1996), John Vervaeke and I argued that this debate cannot be resolved until its participants become explicit about what they mean by "cause." More importantly, by employing a sophisticated analysis of causation developed by Stephen Yablo (1992), the argument itself is shown to dissolve: symbolic and connectionist levels of description are both explanatory and causal, but of different things.

Other recent theoretical works include:

Green, C. D. (2001). Operationism again: What did Bridgman say? What did Bridgman need? Theory and Psychology, 11, 45-51.
Green, C. D. & Vervaeke, J. (1997). The experience of objects and the objects of experience. Metaphor and Symbol, 12, 3-17.
Green, C. D. & Vervaeke, J. (1997). But what have you done for us lately?: Some recent perspectives on linguistic nativism. In D.M. Johnson & C. Erneling (Eds.), The future of the cognitive revolution. Oxford: Oxford University Press.
Vervaeke, J. & Green, C. D. (1997). Women, fire, and dangerous theories: A critique of Lakoff's theory of categorization. Metaphor and Symbol, 12, 59-80.
Green, C. D. (1996). Fodor, functions, physics, and fantasyland: Is AI a Mickey Mouse discipline? Journal of Experimental and Theoretical Artificial Intelligence, 8, 95-106.
Green, C. D. (1994). Cognitivism: Whose party is it anyway? Canadian Psychology, 112-123.
Green, C. D. (1992). Of immortal mythological beasts: Operationism in psychology. Theory and Psychology, 2, 287-316.