Pieces-Light-Science-Illuminates-Stories/dp/0062237896/ref=tmm_hrd_title_0?ie=UTF8&qid=1401831585&sr=1-1">Pieces of Light: How the New Science of Memory Illuminates the Stories We Tell About Our Pasts
By Charles Fernyhough
(Harper, 320 pages, $26.99)

How far back is your earliest memory? What age? In a recent Canadian study cited by Charles Fernyhough, the average was four and a quarter years. “Very few memories dated from before the age of about two and a half.”

I’m out in the early tail of that distribution. My family moved from cramped rented rooms to a spacious new house a few days before my third birthday. I remember the move in some detail; and I have half a dozen memories of the rented rooms.

At least I think I have. One of Fernyhough’s themes is the unreliability of memory. There are true things we remember; there are stories we were told that somehow end up among our memories; there are dreams and imaginative flights we take for true memories; and there are second-order memories—memories of having remembered one of the preceding.

It’s a tricky business, remembering, especially when tangled up with emotion. Memories of trauma, however vivid, are subject to the same kind of distortions as ordinary memories, with obvious legal implications. Even “flashbulb memories”—who will ever forget where he was and what he was doing when he heard that …—are untrustworthy, though they come with unusually high levels of confidence in their authenticity.

The author’s chosen scope is restricted to autobiographical memory—our memories of our own lives. He has not much to say about working memory (holding a phone number in your mind for as long as it takes to dial it) or semantic memory (who was the thirteenth President?). He offers no tips for improving your memory. Pathologies of memory are mentioned only to contrast the normal workings. The book has just three index references to Alzheimer’s.

Within that scope Fernyhough delivers a good survey, illustrated with many personal anecdotes. Several key themes recur.

One is that the mental processes involved in negotiating our private pasts are intimately linked to those for finding our way round in space. Fernyhough gets lost in three different locations that are familiar to him from past acquaintance, to “demonstrate that we can get lost in our pasts in the same way that we get lost in an unfamiliar terrain.” (I am pleased to learn that there is a published book by a different author titled A Field Guide to Getting Lost.)

Another key theme is the close connection, both in known brain functioning as revealed by scans and also in our inner lives, between memory and imagination. In fact a sufficiently intense imaginative effort can create a false memory, a process known to the experts as “imagination inflation.” Even bizarre imaginings can become “real” memories. Test subjects asked to either perform, or just to imagine performing, the act of proposing marriage to a campus Pepsi machine, generated memories of having done so in both cases. “You only need to imagine proposing to a Pepsi machine once to run the risk of having a false memory for having done so.”

“Memory, memory, what do you want from me?” moaned Paul Verlaine. A more interesting scientific question is: What do we want from memory? What’s it for? Nowadays we naturally form hypotheses about such issues in terms of the evolutionary history of our species.

This line of thought leads to the idea that memory is as much about the future as the past.

We evolved the ability to remember … so that we could keep certain important objectives in mind and then ensure that we had achieved them.

Remarkably, neuroimaging research supports this notion. Brain systems known to belong to the core memory system are also active when we think about what is to come. Just as space and time overlap in our memory functions, so do past and future.

This feature shows up again in research on the “reminiscence bump,” the peak density of events that adults recall from around age twenty. When children aged ten to fourteen are asked to imagine their future lives, the imagined events likewise cluster around age twenty. You may be ten or you may be eighty, but in some inner core, you are forever twenty.

As several of the Amazon reviewers noted, Pieces of Light might have been a better book with more matter and less art. The lengthy narratives about getting lost in long-unvisited locales would have been easier to follow with maps. A few of the informative sentences have to be read twice before their content is extracted: 

In fact, an autobiographical memory happens when fragmentary, perceptual episodic information stored in the sensory cortices becomes connected to autobiographical knowledge structures, so that the memory can acquire a personal dimension and the remembering self is placed conceptually and experientially in time. 

Got that? Some other passages are afflicted with the horrid blight of Creative Writing: “The images that he has stored … make the heart race and the souls swoon. His thought is a multicolored pageant of ideas …”

If you don’t mind a personal, novelistic approach to an interesting topic, though—and to judge from magazine sales, not many of us do mind—Pieces of Light is worth a look. I shall probably remember reading this book: it was my birthday.