The Leo Apostel Center

in collaboration with the Doctoral Programme of the VUB invites everyone 
to the 40th of its interdisciplinary seminars in the Foundations series. 
In this series CLEA invites scholars that are actively engaged in the 
research on the foundations of a particular discipline. Their lectures 
will always be directed to an interdisciplinary audience, and the 
discussions aim at confronting the foundations of the different 
disciplines.

Is Quantum Computation Relevant to the Brain?


The Penrose-Hameroff 'Orch OR' model of Consciousness


by Prof. Dr. Stuart Hameroff


(Departments of Anesthesiology and Psychology, University of Arizona, 
Tucson, USA)


Monday, August 23, 1999 at 5 p.m. in room 5/B 406 (building B, 5th floor)
Vrije Universiteit Brussel, Campus Oefenplein

About the lecture 

Enigmatic features of consciousness (e.g. nature of experience/"qualia", 
binding, pre-conscious to conscious transition, "non-computability", free 
will) suggest that reductionist/emergent approaches by themselves are 
insufficient to fully explain consciousness. Additional 
panexperiential/panproto-psychist approaches may be necessary in which 
the nature of experience ('qualia') and other enigmatic features derive 
from a fundamental (quantum) feature of reality, and "proto-conscious" 
qualia are intrinsic to nature, like mass, spin or charge. How could 
subtle quantum effects be linked to brain processes? The Penrose-Hameroff 
"Orch OR" model suggests that quantum superposition/quantum computation 
occur in protein microtubules within the brain's neurons. The quantum 
computation in microtubules (isolated from environmental decoherence by 
biological mechanisms) is suggested to proceed according to the 
Schrodinger equation until threshold is reached (after tens to hundreds 
of milliseconds) for "self-collapse" of the quantum wave function by the 
Penrose-proposed quantum gravity mechanism (objective reduction - "OR"). 
Outputs of each quantum computation chosen in the OR self-collapse are 
particular states of tubulins within microtubules which then govern 
neuronal activity including synaptic function. At a deeper level, each OR 
self-collapse is a self-organizing event in proto-conscious ("funda-
mental") spacetime geometry. We suggest these events may be "conscious 
moments" (Whitehead "occasions of experience") occurring for example at 
40 Hz. In the model, biological factors provide feedback to "orchestrate" 
the quantum computation in microtubules (orchestrated objective 
reduction---"Orch OR"). The Orch OR model is testable, and can 
potentially solve enigmatic features of consciousness. As quantum 
computation becomes technological reality, the brain/mind may inevitably 
be compared to a quantum computer.

About the speaker

Prof. Dr. Stuart Hameroff (l947) practices and teaches clinical 
anesthesiology at University Medical Center and does research into the 
mechanism of consciousness at the University of Arizona. He studied 
chemistry, physics and mathematics at the University of Pittsburgh. In 
1973 he got his M.D. at the Hahnemann Medical College, Philadelphia. In 
the early 1990's he was strongly influenced by Roger Penrose's The 
Emperor's New Mind (and later Shadows of the Mind, Oxford Press, 1989 and 
1994). In 1994 he co-organized an international, multidisciplinary 
conference "Toward a Scientific Basis for Consciousness" held at the 
University of Arizona. A book of selected papers from that conference 
(Toward a Science of Consciousness -The First Tucson Discussions and 
Debates, S Hameroff, A Kaszniak, A Scott, Eds., MIT Press/Bradford Books, 
Cambridge MA) was published in the spring of 1996. He began to formalize 
his efforts in a proposed "Center for Consciousness Studies" at the 
University of Arizona.
The Tucson III conference was held in 1998 and selected papers are in the 
third book in the MIT Press series (with David Chalmers joining as co-
editor) due out late 1999 or early 2000.

The presentation with questions will last about an hour. Afterwards, an 
hour or more is reserved for an in-depth, group discussion of the topic. 
More info at the CLEA office: phone 02-644 26 77 or via the Web-page: 
http://pespmc1.vub.ac.be/CLEA/