The term 'nootropics' is neurobiologically inaccurate as the brain does not have a general 'smart' circuit.

“And as many of you have probably heard me say before, I am not a fan of the word nootropics because nootropics means smart drugs. And, frankly, the brain doesn't work that way. The brain has neural circuits for focus. It also has neural circuits for creativity and neural circuits for task switching and for imagination and for memory. There is no such thing as a neural circuit for being smart. And therefore, the word nootropics doesn't really apply to anything specific neurobiologically speaking.”