KWLee,
In my reply to AlexK, I guess I should have pointed out that I was referring to studying via PR, which uses both the conscious and the nonconscious minds. Maybe I am assuming that the majority of the learning process is done by the nonconscious.
Now that I think of it, I wonder if creating the neural pathways is done by the conscious mind or the nonconscious? I was assuming the latter, as the PhotoReading step blasts the information directly into the nonconscious.
In any case, I think that any limit on study time is highly individual.
