One in a series of talks from the 2019 Models of Consciousness conference. Sir Roger Penrose

Mathematical Institute, University of Oxford

A common scientific view is that the actions of a human brain could, in principle, be simulated by appropriate computation, and even that it may not be too far into the future before computers become so powerful that they will be able to exceed the mental capabilities of any human being. However, by using examples from chess and mathematics, I argue, that the quality of conscious understanding is something essentially distinct from computation. Nevertheless, I maintain that the action of a conscious brain is the product of physical laws, whence consciousness itself must result from physical processes of some kind. Yet physical actions, over a huge range, can be simulated very precisely by computational techniques, as is exemplified by the LIGO gravitational wave detectors confirming precise calculations, within Einstein’s general relativity theory, of signals from black-hole encounters in distant galaxies.

Despite this, I argue that there is a profound gap in our understanding of how Einstein’s theory affects quantum systems, and that there is reason to believe that the events termed “collapse of the wave-function” take place objectively (gravitational OR), in a way that defies computation, yet should be observable in certain experiments. It is argued that each such event is accompanied by a moment of “proto-consciousness”, and that actual consciousness is the result of vast numbers of such events, orchestrated in an appropriate way so as to provide an actual conscious experience (Orch-OR).

Filmed at the Models of Consciousness conference, University of Oxford, September 2019.