 Some writers have emphasized the apparent mismatch between the sentential structure of propositional attitudes on the one hand, and the actual neurological structures of the brain on the other hand. Whereas the former involves discrete symbols and a combinatorial syntax, the latter involves action potentials, spiking frequencies and spreading activation. As Patricia Churchland (1986) has argued, it is hard to see where in the brain we are going to find anything that even remotely resembles the sentence-like structure that appears to be essential to beliefs and other propositional attitudes.