It sounds like he is mixing up the research in 'brain training' and recovery from PCS. None of the brain training research has yet demonstrated that brain training aids in recovery from PCS. But, vegging out will not cause recovery. You need to maintain a minimal level of stimulation. By this, I mean stimulating one sense at a time with a single stimulation. Multi-sensory stimulation may be too much for a recovering brain.

It is not difficult to determine what level of stimulation does not cause an increase in symptoms. We all have our own limits.