Abstract

Two operations, e.g. measurements, successively applied to the state of a system are said to be non-commutative if the sequence of their application makes a difference for the final result. Non-commuting operations play a crucial role in quantum theory, where they are intimately related to concepts as central as those of complementarity and entanglement. However, their significance is not restricted to the small dimensions of the microworld. For reasons easy to understand, non-commuting operations must be expected to be the rule rather than the exception for operations on mental systems. We demonstrate this with a few examples from our own work, and hope this may contribute to the increasing attention that this exciting new area in consciousness studies is currently attracting worldwide