WHY WE REMEMBER

A professor of neuroscience and psychology delivers a wide-ranging study of how memories make us who and what we are.

Memory is a quirky thing, writes Ranganath, director of the Dynamic Memory Lab at the University of California, Davis. We can remember song lyrics from 20 years ago, but we can also forget what we ate yesterday. The author has been trying to understand memory for decades, and he admits that a huge amount still remains a puzzle. He explains the mechanisms of memory in the brain and the different types and levels of memory, as well as the evolutionary reasons for it. Many theories have been posed about how memories develop, but the current thinking involves “a phenomenon called error-driven learning,” where memory is a constant process of reworking experiences to fit our larger mental picture. Memory failures have been linked to depression, poor sleep, and other ailments. Ranganath explains how fake “memories” can be inserted by repeated suggestion, to the point that people have “remembered” and confessed to crimes they didn’t commit. Some memories, especially those of traumatic events, break into our consciousness unbidden. The author suggests that they can be kept under control by persistent and intentional rejection, although it takes effort. He also offers tips on how to not forget routine things (phone, keys) by connecting their image to something else. It’s useful advice, but much of the book is devoted to Ranganath’s examination of theories of memory and the new generation of testing. Anyone expecting a simple how-to guide on improving their memory may be disappointed. The author’s research is undeniably intriguing, but the book will appeal to specialists more than general readers.

A well-informed tour of a mysterious and crucial part of the brain, promising greater self-awareness and mental clarity.