Obviously, if you can’t find any examples (or hardly any) of the exact sentence in question, that would tend to support Taeglich’s point of view. 
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But Amy, what’s your point of view on this? And how about Alan’s point of view. Is that not also important here?
- If you stop, listen and “watch” what’s in your mind…
- What’s in your mind?
Do you think “what” has the same function in each of these examples, M?
MrP
From now on, I’m going for the “could you answer my question before I answer yours, MrP?” approach. Hope that’s OK.
The question was:
So, natives, is “What’s in your mind?”, as Taeglich suggests, wrong?
In times of post-constructionist theories, everything’s possible, nothing is wrong, we can talk about everything, and all depends on personal preference and liking. If you’re asking me, I’d generally prefer “What’s on your mind?” and leave any other possible form to pre-constructionists.
Ah! I had forgotten that Molly may ask questions till the dikgomo come home; but dislikes it intensely when Mollyesque questions are directed his way.
I’ll rephrase accordingly:
“You have erroneously assumed that what has the same function in each of those examples, M.”
As for your question, you may find my answer in an earlier post.
All the best,
MrP
“What’s in your mind?” sounds unnatural if you want to ask “what are you thinking?”. I’d use “what’s on your mind?” or “what do you have in mind?” which in this case means “what do you want to do?”. In some of your examples of “What’s in your mind?” usage, in context, they are appropriate.
MrP, look back and see just how many questions of mine you’ve “ignored”. At least you could be honest about that.
As for the answer to your question, “no”.
Indeed they are. So what would be your reply to the thread poster?
You could begin by telling the poster that a search of both the BNC and COCA for the question What’s in your mind? (as well as What is in you mind?) results in this this response:
(From there, you could go to Google, look for examples of “What’s in your mind?” and analyze those. Judging from your previous post, however, it looks as though you were unable to find any examples of that question that were worthy of your analysis.)
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In doing that, what conclusions, if any, would you want the poster to draw?
BTW, there is one example in COCA.
Care to post it? (Or didn’t you bother to actually look at it?)
I posted it earlier. Did you miss it?
To me, “what’s in your mind?” is equivalent to “what do you see in your mind’s eye?”. Personally, I’d avoid using it completely.
To answer the original poster, I’d say don’t use “What’s in your mind?” as a stand alone question. In context, it’s OK, not by itself because like I said, it sounds unnatural even though I’d understand what you mean.
I haven’t seen you post any actual usage examples of the question “What’s in your mind?”
Do you know the difference between fact and fiction, Molly?
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I must say, you’re a very demanding stalkee. But if you list the questions I’ve “ignored”, I’ll see what I can do.
MrP
Seconded.
MrP
Thank goodness you found an example. 
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