After recent events, some will already be nostalgic for a pre-Trump world. Yet nostalgia is a feeling of familiarity which doesn’t always connect to actual memories. Indeed those who wanted Trump to make America great again were harking back to a version of the country that never really existed. Research has found that the brain systems which control recognition and familiarity are quite different from each other. The two usually work together but can be activated separately, meaning it’s possible to feel a strong sense of acquaintanceship with a place or thing, when in fact you have never been here or used it before.
This is why you can completely forget where and when you were introduced to someone, but just know that you’ve seen them before. Familiarity is instant, whereas memory recall can be a slow process - with lots of effort, it’s sometimes possible to remember the room where you met them, or the time of year it was. These details can then help unearth the full memory, something we should rely upon more than fleeting familiarity, especially in the post-factual world we live in.
Dr Daniel Glaser is director of Science Gallery at King’s College London
