> t's not clear how you get an actual comparison of "effectiveness" from year 0 to year 4. You'd probably need a few different measures of attention/executive

> t's not clear how you get an actual comparison of "effectiveness" from year 0 to year 4. You'd probably need a few different measures of attention/executive function and you'd need to counterbalance them across people to prevent habituation. Given that the regulatory bodies don't require studies like this, it's unlikely to ever happen.