Despite the impressive amount of financial resources invested
in carrying out large-scale brain simulations, it is
controversial what the payoffs are of pursuing this project.
The present paper argues that in some cases, from designing,
building, and running a large-scale neural simulation,
scientists acquire useful knowledge about the computational
performance of the simulating system, rather than about the
neurobiological system represented in the simulation. What
this means, why it is not a trivial lesson, and how it advances
the literature on the epistemology of computer simulation are
the three preoccupations addressed by the paper