Neurofeedback is one of the most peculiar, novel and scientifically researched mind training methods I have come across.
I find it difficult to explain, but essentially brain wave sensors are placed on the head giving a feedback loop which can regulate the brain and/or train particular attributes using a simple reward system.
Like a lot of ‘mind training’ methods, from starting to be used only to treat difficulties (late 1950's), it is evolving into peak performance.
I would recommend checking it our particularly if you know anyone struggling with autism or trauma.
Here is a link to a centre I know in the UK: