" Ninety hours of playing action games led to hippocampal atrophy in response learners, while 90 hours of playing 3D games led to increased grey matter within the hippocampal memory system of all participants."
How the hell can you measure that from a mere 90 hours? That's nothing. It'd be like your brain is literally shrinking in your head. There's no way this is accurate. It doesn't even show their sample size for crying out loud. There's more questions than answers here. It also assumes that FPS games don't involve planning or spatial awareness, which is complete bullshit.