Here is my opinion and some more general points:
We interpret "theory" in TCS broadly, so in general interdisciplinary questions can be on-topic on cstheory.
The main questions one should ask oneself before posting a question on cstheory are:
Is there a reason to think that I will receive a satisfying answer to my question from theoretical computer scientists?
Is there a reason to think that answering the question requires the expertise of theoretical computer scientists?
If yes then cstheory can be a good place to ask it.
If no (e.g. an expert in cognitive science is more likely to answer the question in a satisfying manner for OP, or there is no reason to believe answering the question needs the expertise of a theoretical computer scientist) then probably not.
It might be good to think about this and include it in your question as motivation, it can make it interesting for other users.
You should also formulate your question such that it does not fall into non-constructive or not-a-real-question categories. When people ask a question they are seeking help from others, they are asking others to spend time to read and think about the question. So we expect people to ask only questions that they really care about (if you really care about a question you will spend time and effort on it, and the effort correlates with the quality of the question). We expect people to spend time doing their part before asking others for help, e.g.
You have tried to answer your question yourself first (Google, Wikipedia, Complexity Zoo, etc.) before asking it on cstheory,
You have thought about the question enough to be able to formulate it clearly and in a way that can be answered, you know what you are looking for,
You have spent time to formulate your question using the language and terminology of theoretical computer scientists and following the norms of their community,
You have spend time to write your question in a clear and easy to understand format for theoretical computer scientists.
FAQ contains more tips about writing better questions.