I'm talking about Henry Molaison (HM), the famous memory research patient. I hear that he could converse normally with a researcher until he "got distracted", at which point he no longer remembered ever meeting the researcher.
Molaison was able to remember information over short intervals of time. This was tested in a working memory experiment involving the recall of previously presented numbers; in fact, his performance was no worse than that of control subjects (Smith & Kosslyn, 2007).
If distractions were avoided, how long could HM focus and remember the present or task at hand? How long could he talk to researcher before forgetting ever meeting him?
I hear that he was tested for hours. During those tests, did he had to be reminded at some time interval about the test procedure?