Thx.But the main mission I posted this thread is to make sure stutter isn't ireversible cuz it's for real I didn't find any papers exclaiming stutter can never recover.I think the view point that it's irreversible is speculated by laymen like us,not neurologists or linguists or something else. But what surprises I can make for u are stutter's somatic responses resemble anxiety disorder's,and mental activities really impact on stuttering a lot. And the other is it's not rational to compart physiology from psychology and vice versa. Bear in mind that psychology is surface feature of physiology and physiology elaborates pyschology's phenomenon and principles and so on. Also,they are interacting on each other.