What you truly are before, during and after thought, sensation or perception is the wide open screen of awareness. Borderless presence/knowingness. Infinite and eternal. 
Thought, sensation or perception is your intimate dream. 
Arising out of yourself as thought, perception or sensation, you do not arise. 
Appearing to yourself as thought, perception or sensation, you do not appear. 
Perceiving yourself as thought, perception or sensation, you are not perceived.