Fascinating:

The primary problem E.P. experienced came in what we’d probably call conscious memory, or what professionals call declarative memory. This involves, as the names imply, the ability to be aware of something we know, and to state it, whether it’s a historic event or the term for an obscure object. For example, E.P. moved to San Diego shortly after his illness, but he was never able to consciously remember the layout of his apartment or where the Pacific Ocean was, even though it was two miles from home. And although he could relate stories about the events of his youth, he’d often get repetitive while doing so—after all, he couldn’t remember which parts of the stories he’d already related.

But that doesn’t mean he had no memory. We store short-term information (like the digits we’re carrying when we’re doing math) in a place called working memory—and E.P.’s working memory was just fine. In some tests, he was blindfolded and led along a path up to 15 meters in length. When it was over, he was able to remember his start position successfully. But wait a few minutes, and the entire test faded from his memory. When asked, he’d tell the researchers that he’d been “in conversation” a few minutes earlier.

Full Story: Ars Technica: Understanding the brain of a man with no conscious memory

(Remind anyone of Memento?)