Having successfully used them to reduce seizures in psychotics, Scoville decided to remove  H.M.'s hippocampus, a part of the limbic system that was associated with emotion but whose function was unknown.
Meqë kishte përdorur ato me sukses në reduktimin e sulmeve psikotike, Scoville vendosi t'i heq "H.M"-it hipokampusin, pjesë e sistemit limbik e lidhur me emocionet por funksioni i të cilës ishte i panjohur.