The same question can also be asked in a different way:

Fortunately, we can ask this question also in a slightly different way. We can ask whether the amount of personality shift increases after the infection or not. When the toxoplasmosis induces the shift than the amount of this shift should increase with the duration of toxoplasmosis. When the personality shift occurs before the infection no correlation or even negative correlation between the amount of personality factor shift and duration of toxoplasmosis can be expected to exist.