(Theodore Ribot, in The Diseases of Memory published in 1881, pointed out that the first characteristic of amnesia in patients with dementia is the loss of memory for recently experienced events with relative preservation of remote events.)
I opened an email from Greg, a classmate at Brown some 50 years ago, that include a link to a recent article in The Guardian titled “Stop drinking, keep reading, look after your hearing: a neurologist’s tips for fighting memory loss and Alzheimer’s.”
I appreciated his thoughtfulness in sending it to me as I am always on the lookout for articles that might generate the inspiration for a blog episode. This article was an interview with Dr. Richard Restak and the occasion was the release of his new book The Complete Guide to Memory: The Science of Strengthening Your Mind.
I googled the book before I even finished reading the article, then downloaded the electronic version so I could scan its contents. A lot of the usual material was covered and I was struck by the fact that here was yet another neurologist covering a lot of the same material that is standard for this type of tome. It didn’t look like there was much that I hadn’t covered in prior posts.
As I was moving it to the trash, though, I noticed that I had previously downloaded this very book!
Strange, I thought, that I hadn’t recognized the cover art. The name ‘Restak’ seemed familiar, but I couldn’t place it. Thinking logically, I realized that I must have read the book and, therefore, I must have blogged about it. So I scanned the titles of all my posts looking for one in which I might have written a review of the book. Since nothing jumped out at me, I began opening posts with potentially related titles and soon found it. It was S2E28: Working Memory Workout? published on July 15th.
That was only a month ago…and my memory of reading that book had all but evaporated!
What a kick in the pants! Here I was doing daily workouts to improve brain performance and I just had a major fail of episodic memory, the kind of memory malfunction that Ribot described back in 1881.
Episodic memory is our memory of what happens to us: what we do and what we experience. How could I not remember reading this book just a few weeks ago when I had obviously spent a lot of time reading it, thinking about it, and finally writing about it?
Forming an episodic memory has three stages. First you have to pay attention to the event. Basically, if it didn’t make much of an impression when you first experienced it, it’s unlikely that you will recall it later on.
Second, you need to encode it into memory. You do this by thinking about it, processing it, replaying it, and linking it to other experiences so it fits into a framework for remembering.
Finally, you need to be able to retrieve it. Recall memory is when you can retrieve it from your memory banks without any assistance. Recognition memory is when you need cues or hints in order to find it. Unsurprisingly, recognition is easier than recall. In either case, though, the memory must have been encoded for you to unearth it later on, with or without a little help from your friends.
So what had happened to cause my memory failure? I clearly had paid attention to the book and processed it more than enough to guarantee encoding. It would be easy to conclude that this was therefore a retrieval error…but maybe not. Why did it not come rushing back to me after seeing multiple cues, including the cover and table of contents? Alternatively, the breakdown could have been caused by a failure in any one or in any combination of the three functions.
I did a quick web search of articles about episodic memory and came across one that suggested you could improve it by watching a movie and then listing as many of the scenes as you could remember. It seemed to me that this could also serve as a reasonable test of your ability to recall episodic memories, so I tried it with a movie I had just watched the night before: ‘Hud’ starring Paul Newman.
I waited 5 days to give my brain a chance to consolidate the memory and, perhaps, even time enough to forget a little about it before attempting the task.
Now, obviously, I don’t know how many scenes there were nor how many scenes a brain-healthy 71-year old would remember, but I came up with 43.
I’ve got to believe that that’s pretty good. I’m pretty sure I didn’t miss much, so I’m going to put off worrying about any possible episodic memory failures for the time being.
But it is a little scary to see how it might sneak up on you.