Memories are made of this

Pieces of Light: The New Science of Memory, by Charles Fernyhough, Profile, £14.99, 344 pages

Charles Fernyhough set out to write a book about the science of memory and ended up telling a lot of stories.

There are two main reasons why stories, particularly about his own family, dominate Pieces of Light. Fernyhough, an academic psychologist whose writing has ranged from popular science to fiction, happily acknowledges the first: that narrative seems an appropriate medium for memory more than for any other aspect of human experience.

The second reason, which Fernyhough is less willing to admit, is that the science of memory is still so rudimentary, indeed fragmentary. He claims that the field “has never been more vibrant” – which may be true – and of course the new tools of neuroscience such as brain imaging are enabling researchers to make some progress. But this vibrancy is still far from producing a clear understanding of how memory works. There is no convincing account of the overall process by which different types of memory are encoded in the brain, stored and then retrieved.

We do not even know how localised or distributed the process is – to what extent the components of memory are divided between individual neurons or spread through the brain. Some neuroscientists believe we have hyper-specific neurons, often called “grandmother neurons” because a single cell will hold an image of your grandmother and enable you to recognise her, while other experts believe even the most specific of memories are far more spread out than that.

Although Fernyhough does not mention grandmother neurons in Pieces of Light, his own 93-year-old grandmother Martha gets a whole chapter. He tapes extensive interviews with Martha, drawing out her memories of life in the Jewish East End of London during the 1930s. The anecdotes here are lively, even touching, as Fernyhough reflects on the “reminiscence effect” – the tendency for events from our teens and early twenties to stick in the ageing memory better than anything else.

Readers of Fernyhough’s last book will be familiar with his autobiographical approach. The Baby in the Mirror explored mental development in infancy through his daughter Athena’s life from birth to three. Athena (now nine) and her younger brother feature in Pieces of Light too, though much less prominently.

But the author plays a key role in his own book. In early middle age, he returns to places that were very familiar to him in childhood and young adulthood – the Essex marshes, Cambridge and Sydney – to see how much he can remember and whether he still knows enough to find old haunts. Needless to say, he gets hopelessly lost. Though Fernyhough is a gifted writer who can turn any experience into lively prose, these autobiographical passages are the least successful of Pieces of Light because they are too disconnected from any scientific insights about memory.

Better are passages when Fernyhough meets and analyses people whose memories have gone wrong, through trauma or disease. For instance, Colin remembers a tragic road accident too well and cannot stop obsessing about the horrific details – inaccurately, it turns out – until therapy stitches together these memories into a new form that is more accurate and less traumatic for him.

The most important message of Pieces of Light is that the “reconstructive nature of memory can make it unreliable”. It is wrong to see memories as fixed biochemical or electrical traces in the brain, like books in a giant library that you could access if only you knew how. Whenever you retrieve a memory, it is integrated into your current thinking according to the demands of the moment and it may undergo permanent change after you let it go.

People are becoming increasingly aware that memory is unstable. The stories in Pieces of Light may convince a few more – and will entertain anyone who reads them. But in disabusing us of our misconceptions, Fernyhough leaves us with little sense of a scientific narrative to put in their place.

Clive Cookson is the FT’s science editor

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