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Machines Like Us

Machines Like Us interviews: Susan Pockett

Monday, 20 June 2011

To my mind the question of what makes consciousness go away during anaesthesia is very much more interesting -- and therefore, of course, it has been very well studied using more traditional methodologies. When I first lost my research job in the mid 90s I hatched a plan to fund my increasing interest in consciousness by inventing a consciousness monitor for anaesthetists. Nothing along those lines was then available and it was just starting to be reported that patients occasionally do wake up on the operating table, unable to signal that fact because it's standard practice to paralyse and ventilate people to keep them still for the surgeon. At that stage there were already a huge number of papers in the clinical literature suggesting that middle latency auditory evoked potentials would be the best correlates of consciousness for use in such a device. These transient EEG events are relatively easily measured, they do go away in concert with awareness during clinical anaesthesia, and hearing is the last thing to go during the transition from waking to either natural sleep or chemical anaesthesia. So I duly applied for a grant, got the magnificent sum of $20,000 NZ dollars (which was then worth about $12,000 US dollars), built an auditory evoked potential monitor, convinced the local anaesthetists that this was a good idea, got approval from the regional ethics committee and tested the thing in the operating theatres at Auckland Hospital. It seemed to work OK, though obviously at least one more prototype was going to be necessary. But I couldn't get any more cash -- and about then a US company threw 10 million US dollars at the problem and quickly cornered the world-wide market. Today you'll find one of their anaesthesia monitors in pretty much every operating theatre in the developed world. They basically use EEG, but they process it using a measurement paradigm quite different from the rather obvious one I was using, which they have managed to keep commercially secret. Perhaps their paradigm has improved since the early days, but I vividly recall sitting next to an anaesthetist during one particular operation (before I gave up on the whole thing) and pointing out to him that this company's monitor said the patient was awake. He looked at the monitor, looked at the patient, said "oh that's just another number to worry about" -- and turned off the monitor.

So yes, there has been and is an awful lot of work on measuring consciousness during anaesthesia. Interestingly enough, although objectively all of that work does tend to suggest that consciousness should be NOT an all-or-nothing state, my personal observations (both of being anaesthetised and of watching other people being anaesthetised) tend to suggest that subjectively, it is. For me, going under anaesthesia was like having a black curtain rise from the bottom of my visual field -- when it got to my eyes I was out -- and waking up was like turning on a light switch. I describe those experiences (anonymously) in more detail in a 1999 paper in Consciousness and Cognition.

MLU: Machines Like Us differs from other science websites in that it takes the stance that science and religion are incompatible, and that religion for the most part has been (and continues to be) an impediment to science. In her 2009 AAI lecture, noted astronomer Carolyn Porco put into words our thoughts completely.

How do you feel about religion, and what implications does your electromagnetic field theory of consciousness have for various aspects of religion such as humans supposedly being created by God, or having an afterlife?