The idea that quantum physics might have something to do with consciousness crops up in a number of theories: perhaps most prominently in the version put forward by Penrose and Hameroff, but quite regularly elsewhere – the views of Huping Hu and Maoxin Wu, for example, have been discussed here recently. I sometimes find the motivation of this line of reasoning a little unclear: why exactly do we need to invoke quantum physics, anyway? Sometimes it seems that the quantum theorists are merely hoping that there will turn out to be one solution to two otherwise unconnected mysteries: not actually a very good bet.
Earlier this year, Maurits van den Noort, from the Department of Cognitive Neuroscience at the University of Bergen, came up with yet more reflections on the relevance of quantum effects, but this time there is a difference, in that he puts forward two studies which seem to offer empirical evidence that something unexpected and possibly quantumish is going on in the unconscious emtional reactions of human beings, as revealed by scans and EEG readings. A book is apparently in the pipeline.
Van den Noort gives an admirably clear summary of just how quantum physics might be thought relevant to consciousness:
First, quantum coherence (e.g. Bose-Einstein condensation) is a possible physical basis for ‘binding’ or unity of consciousness (Marshall, 1989). Second, non-local entanglements (e.g. ‘Einstein-Podolsky-Rosen correlations’) serve as a potential basis for associative memory and non-local emotional interpersonal connection. Third, quantum superposition of information provides a basis for preconscious and subconscious processes, dreams and altered states. Finally, quantum state reduction (quantum computation) serves as a possible physical mechanism for the transition from preconscious processes to consciousness (Penrose, 1989; 1994).
He says that quantum state reductions may send quantum information “back in time”, and it is the scope for non-linear information processing which particularly interests him. Acknowledging that a smooth chronological sequence is one of the more salient properties of subjective experience, he points instead to unconscious information processing, and especially to the generation of emotional responses.
The two experiments quoted by Van den Noort involved showing subjects a series of images: some neutral, some emotionally stimulating. (In fact the stimulating images were either erotic or violent, which seems to short-change the emotional life of human beings somewhat, though no doubt it helped to guarantee a clear reaction). Both experiments, whether based on scanner or EEG, produced the same extraordinary result: it was possible to detect an emotional reaction to emotional stimuli just before they actually occurred, even though subjects had no way of knowing whether the next image in the random series was going to be emotionally charged or neutral.
Van den Noort suggests that a likely explanation is that the unconscious mental processes at work here are powered by non-linear quantum information processing. He sees unconscious information processing as a kind of fast but rough system for generating emotional reactions which colour our behaviour, although they remain subject to the slower and more thorough examination of events which takes place on a conscious level.
These results are so remarkable (I’m not sure I can get my head round the implications for Libet’s similarly counter-intuitive findings at all) that it is tempting to assume that something must have been wrong with the experimental set-up: perhaps the images weren’t truly randomised, or the subjects were somehow able to pick up subtle clues of which the experimenters remained unaware. I don’t know of any flaws like this, but I am inclined to think something must be wrong somewhere.
First, the ability to respond to future events, even in the shortest term, is such a useful capacity it seems strange our nervous system doesn’t make better use of it. Our system is certainly set up to produce fast responses in certain cases: when we touch a hot surface, for example, the nerve signal does not even have to spend the small amount of extra time needed to go all the way to the brain: instead, a short loop triggers a hard-wired evasive reponse. If the brain could register emotional events before they happened (and burning your hand, or even nearly burning it, surely does generate some emotion) it ought to be able to set off the reflex evasive action before you actually make contact. I realise that evolution does not necessarily deliver every possible good idea: but this one is so simple and so valuable it seems suprising, given Van den Noort’s findings, that pre-emptive reflexes don’t exist. Second, this kind of experiment, moitoring reaction times to a sequence of images, sounds like a pretty typical piece of psychological research: it seems a little odd that some other researcher hasn’t come across this chronological curiosity before.