Dennett, Consciousness Explained:

 “Conscious human minds are more-or-less serial virtual machines implemented – inefficiently – on the parallel hardware that evolution has provided for us.” (218) 

“with brains it takes training, including especially the repetitive self-stimulation” (219)

KEITH’S IDEA: Meditation, focusing one’s mind on a single thing repetitively, is advanced training for the mind to enhance the efficiency of this serial virtual machine by setting up pathways that strengthen serial processing and quiet the parallel “hubbub” of the random thoughts of the brain in its natural state.