Shadow - try any search engine with 'somatogravic' and you can learn!
As I understand it in simple terms, forward acceleration causes the tiny 'balance' hairs in the ?inner? ear to be tilted backwards (due to inertia) which has the same effect on the brain as tilting the whole body backwards ie pitching nose up.
The brain (deprived of adequate visual reference) can interpret such forward acceleration as a climb and vice versa. Thus a tendency to push forward to stop the climb as the aircraft accelerates.
As the USAF used to say " Disorientated? - Get on the gauges!"
The human balance system was not built for flying!
Try
The Flyer, October 2000