I remember meeting H.M. in the spring of 1967, when he was perhaps 40 years old and I was 16 years his junior. My mentor, Hans-Lucas Teuber, brought him to my tiny office across from the psychology department library at the Massachusetts Institute of Technology. I recall H.M.'s thin, smiling, rather handsome face as he squeezed into the doorway with Teuber, who introduced us as “Don” and “Henry,” as if we might become buddies. I think I called Henry “sir” as we shook hands because he was already a minor M.I.T. celebrity. Teuber assured Henry that he would enjoy taking part in my experiment on sentence comprehension, something he was good at, and excused himself.
As we climbed the stairs to the testing room, it never crossed my mind that this quiet man would become a major focus of my research during the next half a century. I unlocked the door and seated Henry at a wooden desk facing mine, sunlight streaming into the room from large windows to my right. In front of me I had two stopwatches and a stack of 32 short sentences typed onto three-by-five index cards. I started a tape recorder and began what I thought would be a fairly routine experiment.