SINBAD Neurosemantics: A Theory of Mental Representation DAN RYDER Abstract: I present an account of mental representation based upon the ‘SINBAD’ theory of the cerebral cortex. If the SINBAD theory is correct, then networks of pyramidal cells in the cerebral cortex are appropriately described as representing, or more specifically, as modelling the world. I propose that SINBAD representation reveals the nature of the kind of mental representation found in human and animal minds, since the cortex is heavily implicated in these kinds of minds. Finally, I show how SINBAD neurosemantics can provide accounts of misrepresentation, equivocal representation, twin cases, and Frege cases. 1. Introduction As physical beings, how is it that we manage to represent the world? We now have very strong evidence that the human mind is identical with or somehow realized in the brain, specifically in the cerebral cortex. It would thus seem reasonable to hope that an understanding of the cortex might help us understand mental representa- tion, if not in general, then at least in our own case. In taking this particular a posteriori approach, it must be admitted that we run the risk of failing to discover any deep facts about how we manage to represent the world. Perhaps we will discover only that, however it is done, it is done with neurons (about three pounds of them). I decided the risk was worth taking, and in this paper, I will try to show that the results are significantly more impressive: the approach yields a naturalistic account of the principles determining reference (and ultimately truth conditions) for our kind of mental representation—in other words, a neuro- semantics. Some will be skeptical of my strategy from the outset, not because they doubt the mind is realized in the brain, but because they doubt the relation between mind and brain is sufficiently transparent that it may be understood by investigating the ‘hardware’. The standard view is that mind and brain may be linked only via multiple levels of composition and explanation. I believe the link is much more Many thanks to all the people who provided me with valuable comments and discussion, including Dorit Bar-On, Scott Brockmeier, Ruth Campbell, Mark Changizi, Fred Dretske, Chris Eliasmith, Paco Garzo ´n, Chris Hill, Bill Lycan, Mohan Matthen, Ruth Millikan, Stan Munsat, Ram Neta, Jesse Prinz, Zena Ryder, Tim Schroeder, Marius Usher, an anonymous referee for Mind & Language, and especially Oleg Favorov. Address for correspondence: Department of Philosophy and Program in Cognitive Science, Sycamore 026, 1033 East 3rd Street, Indiana University, Bloomington, IN 47405-7005, USA. Email: dan@danryder.com Mind & Language, Vol. 19 No. 2 April 2004, pp. 211–240. # Blackwell Publishing Ltd. 2004, 9600 Garsington Road, Oxford, OX4 2DQ, UK and 350 Main Street, Malden, MA 02148, USA.