I recently read a fanfic which has sparked a plot bunny, but I'm not sure if it's possible. The fanfic had a military working dog that was turned into a human (through an unexplained supernatural force). When he is found in Afghanistan as a human, people assume he is a soldier who was tortured into this state. The author describes:
"He couldn't speak or walk. He pawed at his ears and nose, even though there was no visible injury. He had the motor skills of a toddler: poor hand-eye coordination, difficulty with grasping objects, and a lack of the most rudimentary dexterity. He didn't know how to eat with utensils or wash himself, or do any of a myriad of simple human tasks.
His doctors hypothesized that he had been captured and tortured into a primitive, feral state."
Would this be at all possible, for a human who was tortured to regress to this point? I did some google and scientific journal searching and flipped through a few psychology textbooks, but didn't find anything this extreme. Also, if he experienced head trauma following the torture, would that cause this? I would really appreciate any input on the possibility of this scenario or what it might be called so I can research further (or even knowing if it's completely impossible so I can give up now ;) ).