Fig 4. Mutual information based on binarization of single odor measurements parametric in the threshold.

If all concentrations would be equally likely, chosing the median would provide most information about concentration (indicated as gray curves for comparison). In condition A (fast flow) and B (slow flow) chosing a threshold above the median increases the amount of information about location. The information curve is flat for condition C (boundary flow). Color coding as in Fig 3.