Why should we invest in basic brain science?

I’ve been approached for comment on an in-press paper. Among the questions posed to me was this one:

How does this kind of research benefit society? Why do we need to understand the neuroscience behind perception, learning, and social interaction? Why should we continue to invest in this kind of research?

Good questions. In conversation, I tend to dodge these by saying “it’s just interesting”. I haven’t had to write many grant proposals so far. A little elaboration on “it’s just interesting” seemed appropriate here. All I could come up with was this:

This is basic science. It benefits a society that values knowledge and is interested in finding out how the human mind and brain work. It is also imaginable that one day this research, along with hundreds or thousands of other studies, will help us make progress in the treatment of brain disorders. However, this is speculative at present. Many important advances of technology and medicine are based on basic science. Insight is often useful. But to gain it we must pursue it for its own sake, rather than with a need to justify every step toward it by an application.

I wish I had a better answer. Any suggestions?