News and brain candy for the philosophy community
Metaphysicians of causation have been known to ponder the possibility of causal action-at-a-distance: that is, whether or not it is possible for one event to causally influence another over a spatio-temporal gap. It was common among Early Modern philosophers to insist that causation requires a ‘nexus’ – roughly, a point of contact between cause and effect. (This thought under-wrote many of the objections of principle contemporary critics to Cartesian Interactionism.) Such a view, indeed, is not unreasonable: the idea of causal influence crossing a spatio-temporal gap ‘unmediated’ by some force or other is, to put it bluntly, spooky. On the other hand, however, potential cases of action-at-a-distance have been postulated in certain Quantum Mechanical experiments, most notably the Einstein-Podolsky-Rosen/Bohm experiment. Naturally, the interpretation of the observations in such experiments are debated, but nevertheless a prima facie case for spooky action-at-a-distance exists.
Now, however, a recent article in New Scientist suggests that the phenomenon of quantum entanglement, much like that which seems to occur in the EPR/B experiment, has been observed to occur between groups of neurons in the brain. Furthermore, it is suggested that this may explain the combining of information from different sensory modalities into a single memory.
I’ll let you figure that last part out for yourselves: I’m going to focus on action-at-a-distance. The research was carried out by Dietmar Plenz and Tara Thiagarajan at the National Institute of Mental Health in Bethesda, Maryland. You can read the full text of their article here; in brief, they claim to have discovered that the electrical activity of groups of neurons that rise and fall in patterns (‘coherence potentials’) can be “mimicked or cloned” within a matter of microseconds by other (presumably discrete) neuron clusters up to 10mm distant. It seems, however, that the principle argument for saying that it is ‘spooky-action-at-a-distance’ in play here is the lack of distortion in the copied coherence potential, that might be expected were more ‘regular’ forms of transmission in play. Whether this is Plenz’s argument, or New Scientist‘s, is not wholly clear.
But how good an argument is it? The question might be put as follows: what might make us think that we have ‘real’ action at a distance in any particular case, rather than thinking that the transmission medium is one that we haven’t yet fully understood?
Philosophy of causation: blind alleys exposed; promising directions highlighted
By Ned Block, Massachusetts Institute of Technology
(Vol 1, Feb 2006)