• Mark Brafield

Barbra Streisand, neuroscientist

In 2013 I heard Barbra Streisand sing, live. It was one of the great musical moments of my life, right up there alongside Bernstein conducting Mahler 5 with the Vienna Philharmonic and worth every single one of the very large number of pennies I paid. 'Memories', she sang, 'may be beautiful, and yet, what's too painful to remember is too precious to forget'.

Nice try, Barbra, but with the benefit of modern neuroscience, she might want to think about that again.

Because recent scientific investigations show that our memories are not quite as stable as we might think.

A memory, it turns out, is not like a snapshot stored in an album, or a file locked in a cabinet or on a computer, permanent and unchanging. Instead, a memory may be considered as a constellation of the electrical impulses and chemical connections in the brain that happened to come together at that one point, just as the pieces in a kaleidoscope fall into a particular pattern in one movement and then move on. When you recall the memory, you re - create that particular constellation of impulses and connections. In other words, memory is something you do, rather than something you have.

And here's the interesting bit. When you re - run that process, the memory is altered by the state of mind you are in at the moment of recollection. Every memory is changed by the context in which it is recalled. This may be a subtle re - colouring, or it may be a significant re - writing of what you remembered as completely truthful. Putting it in terms of the parts of the brain, the amygdala - that part of your brain that powerfully imprints the emotional core of a memory - can be altered and over - written by the pre - frontal cortex, the rational part of the brain that can look at situations in a more considered and contextual way.

Once you grasp that model of memory, the implications are considerable. It means, to begin with, that memories are not quite as stable as you might think, and if a memory is precious, that can introduce a note of transient sadness. But on the other hand, if you feel trapped by a memory - which, in one sense, is all a phobia is - you can learn, quite literally, to re - wire the brain so that just as you learned to be frightened of snakes or spiders, or learned the association that makes you dependent on cigarettes, you can learn not to be frightened of them, or that you no longer need the association. Better still, you can learn to override that anxiety response or depression that may have dogged you for years.

But I will still cherish those memories of Barbra Streisand and Leonard Bernstein.