“Memory of Water” Experiments Explained with No Role Assigned to Water: Pattern Expectation after Classical Conditioning of the Experimenter

Introduction. The “memory of water” experiments suggested the existence of molecular-like effects without molecules. Although no convincing evidence of modifications of water – specific of biologically-active molecules – has been reported, consistent changes of biological systems were nevertheless recorded. We propose an alternate explanation based on classical conditioning of the experimenter.Methods. Using a probabilistic modelling, we describe not only the biological system, but also the experimenter engaged in an elementary dose-response experiment. We assume that during conventional experiments involving genuine biologically-active molecules, the experimenter is involuntarily conditioned to expect a pattern, namely a relationship between the descriptions (or “labels”) of experimental conditions and the corresponding biological system states.Results. The modelling predicts that the conditioned observer could continue to record the learned pattern even in the absence of the initial cause, namely biologically-active molecules. The phenomenon is self-sustained since the observation of the expected pattern reinforces the initial conditioning. A necessary requirement is the use of a system submitted to random fluctuations with autocorrelated successive states (no forced return to the initial position). The relationship observed by the conditioned observer is however not causal and has a quantum-like structure. The modelling predicts also that blind experiments with an “outside” supervisor lead to a loss of correlations (i.e. system states randomly associated to “labels”). Conclusion. This psychophysical modelling allows explaining the results of “memory of water” experiments without referring to water or another local cause. It could be extended to other scientific fields in biology, medicine and psychology when an experimenter effect is suspected.