Recalling the future: our memories may be tools for working out what's to come and what to do about it

Predictions in the Brain: Using Our Past to Generate a Future

EDITED BY MOSHE BAR

Oxford University Press: 2011. 400 pp. $99.95

Memory is the most intimate of abstractions. The matter of how memories are made and stored is a research goal that needs no selling, perhaps driven by a fear of memory loss and our dread of personal obliteration. Yet one question has been neglected: why does memory exist?

Possible answers are explored in Predictions in the Brain, a collection of 25 rigorous, data-laden cognitive-science reviews edited by neuroscientist Moshe Bar. He and his co-authors propose that prediction is a unifying principle of brain function, and that predictions are created from memories. As contributor Yadin Dudai writes: "Memories are made mostly for the sake of present and future." Memory systems do not store past experiences, but recycle their components into the imagined future.

In throwing evolutionary light on a fundamental process, this idea has legs. As survival advantages go, our ability to envision and plan a nuanced future is a masterpiece--arguably, the root of our success as a species. If memories are used to generate predictions that drive our actions, then the mechanisms of prediction are...