The use and abuse of large-scale brain models

•We compare and discuss several noteworthy current large-scale neural simulations.•The benefits of large-scale models are outlined.•The importance of emulating brain function when building models is emphasized.•We argue against reliance on emergent behavior in neural simulations.

We provide an overview and comparison of several recent large-scale brain models. In addition to discussing challenges involved with building large neural models, we identify several expected benefits of pursuing such a research program. We argue that these benefits are only likely to be realized if two basic guidelines are made central to the pursuit. The first is that such models need to be intimately tied to behavior. The second is that models, and more importantly their underlying methods, should provide mechanisms for varying the level of simulated detail. Consequently, we express concerns with models that insist on a 'correct' amount of detail while expecting interesting behavior to simply emerge.