In this article, about an unfinished book by von Neumann (he died in 1957 before he could finish it), one can read:
After stating that he himself is neither a neurologist nor a psychiatrist, but a mathematician, Von Neumann embarks upon the first part of this essay by explaining the components of a computer in the language of a computer scientist. First, the difference between analog and digital computers is explained. This distinction will have some relevance for the discussion of the brain because—as stated in the second part—the brain can prima facie be considered as a digital computer. However, upon further reflection, some elements of analog computing (e.g., the chemistry) will also become relevant in understanding the functioning of the brain.
Is he saying the brain is an analogue computer? What does he even mean with that?