Run That By Me Again

I know how déjà vu works.

Look away now if you've heard this before.

Or don't.

Because you probably haven't.

No matter how you set them up, Scalextric cars never perform equally. You know the track length is exactly the same in each lane and it should be a fair race, but the design is fatally flawed.

The track comes in pieces that clip together and the joins are never perfect. Unless you devote permanent space to it, you are constantly dismantling and remantling so bumps, gaps and imperfections appear and the yellow car always loses.

And so it is with how the brain processes new information and how it stores long- and short-term memories. Robert Efron tested an idea at the Veterans Hospital in Boston in 1963 that stands as a valid theory today. He proposed that a delayed neurological response causes déjà vu. Because information enters the processing centres of the brain via more than one path (your imperfect racetrack) it is possible that occasionally that blending of information might not synchronize correctly.

Efron found that the temporal lobe of the brain's left hemisphere is responsible for sorting incoming information. He also found that the temporal lobe receives this incoming information twice with a slight (milliseconds-long) delay between transmissions -- once directly (the red car) and once again after its detour through the right hemisphere of the brain. If that second transmission (the yellow car) is delayed slightly longer (the ill-fitting join after the cicane) then the brain might put the wrong timestamp on that bit of information and register it as a previous memory because it had already been processed.

And that explains the sudden sense of familiarity.

Ta da.