intracephalic

But with regard to intracephalic actions, they are outside the ordinary sphere of our actions.

The Mind and the Brain Being the Authorised Translation of L'Âme et le Corps Alfred Binet 1884

I found it in certain intracephalic movements which we habitually oppose, as 'subjective,' to the activities of the transcorporeal world.

A Pluralistic Universe Hibbert Lectures at Manchester College on the Present Situation in Philosophy William James 1876