Before revision:  We propose a theoretical model that explains these observations: the receptor distribution is tuned to efficiently encode information about the olfactory environment. This adaptation occurs before olfactory signals are decorrelated, leading to a new regime of efficient coding in which the optimal receptor distribution is sensitive to the global context of the correlatedresponses of all receptor types in the population. We demonstrate how this effect reproduces the context-dependence seen in experiments.
After revision:  We show that efficient coding theory predicts precisely such a context-dependence seen in experiments.