Recently the neurologist and author Oliver Sacks recalled a vivid childhood memory, recounted in his autobiography, Uncle Tungsten.
During WWII he lived in London during the Blitz, and on one occasion:
"…an incendiary bomb, a thermite bomb, fell behind our house and burned with a terrible, white-hot heat. My father had a stirrup pump, and my brothers carried pails of water to him, but water seemed useless against this infernal fire—indeed, made it burn even more furiously. There was a vicious hissing and sputtering when the water hit the white-hot metal, and meanwhile the bomb was melting its own casing and throwing blobs and jets of molten metal in all directions."
Except when his autobiography came out, one of his older brothers told him he’d misremembered the event. In fact both of them had been at school when the bomb struck so they could not have witnessed the explosion.
The ‘false’ memory, it turned out, was implanted by a letter. Their elder brother had written to them, describing the frightening event, and this had lodged in his mind. Over the years the letter had gone from a third-person report to a first-person ‘memory’.
Turning the memory over in his mind, Sacks writes that he still cannot see how the memory of the bomb exploding can be false. There is no difference between this memory and others he knows to be true; it felt like he was really there.
This sort of experience is probably much more common than we might like to imagine. Many memories which have the scent of authenticity may turn out to be misremembered, if not totally fictitious events, if only we could check. Without some other source with which to corroborate, it is hard verify the facts, especially for events that took place long ago.
That these sorts of distortions to memory happen is unquestioned, what fascinates is how it comes about. Does the long passage of time warp the memory, or is there some more active process that causes the change?
A study published recently sheds some light on this process and provides a model for how memories like Sack’s become distorted.