Bayesian reasoning implicated in some mental disorders

From within the dark confines of the skull, the brain builds its own version of reality. By weaving together expectations and information gleaned from the senses, the brain creates a story about the outside world. For most of us, the brain is a skilled storyteller, but to spin a sensible yarn, it has to fill in some details itself. "The brain is a guessing machine, trying at each moment of time to guess what is out there," says computational neuroscientist Peggy Seriès. Guesses just slightly off -- like mistaking a smile for a smirk -- rarely cause harm.