Complex sentence: He has been active since the early 1990s in the promotion of consciousness as a scientific endevour, and has been particularly influencial in arguing that consciousness can now be approached using the modern tools of neurobiology.
Split into simpler sentences: He has been active since the early 1990s in the promotion of consciousness as a scientific endevour. Being particularly influencial in arguing that consciousness can now be approached using the modern tools of neurobiology.