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Memory - It’s Just A Hop, Skip and A Jump Away

posted Jul 20, 2015, 9:47 AM by Ellen Pearlman

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Rat place cells lighting up over 1/5 of a second in sequential order left to right. Photo - Pfeiffer and Foster, Science, 349:180)(2015)

Scientists have discovered memory is a series of snapshots, strung together. The snapshots can  mix and match,  get lost, while others fill in to replace them. In the art world, a frequently used sobriquet to describe various works is they are about “memory and loss.” Now scientists at Johns Hopkins have shown memory in linear formation occurring in rats “place cells,” illustrating a reality of how memory actually happens. 

The rats are shown food it a location that is not within immediate reach. They think about how to obtain the food. The place cells that are activated when they are planning a route reside in the hippocampus of the brain. Their neural activity ‘hovers’ on a spot  in a neuron for about 20 milliseconds before jumping to the next spot down the line. This seems to account for the idea that someone’s name is “on the tip of my tongue’ when it comes back to you after you originally forgot it. Memory takes time to work its way down the neural rope.

One group or network of neurons controls the actual snapshot images that develop, and a second group controls stringing the snapshot images together in the proper order.  At first memory seems to be blurry, and then it tunes in and gets focused. Perhaps that is why repetition strengthens memory. Memorization in many cultures measures intelligence - but is it just measuring neuron connection strength? That could change a lot of traditional ideas about intelligence. 

Memory formation is also linked to slow gamma waves in brains - a state usually associated with being ‘in the zone’ including peaks of performance. Gamma waves are also produced by deep meditation. 

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Types of brain waves

In the picture below, scientists ‘smoothed’ the track because the original was noisy and had gaps, but you can still get an idea of it here.  Its like a railroad track or superhighway of memory. Sometimes it seems to skip a jump. I guess that is what we call “a senior moment.”


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Photo - Pfeiffer and Foster, Science, 349:180)(2015)

But really, what is memory? What endures and why? Was I always the little girl. When did I grow up? Who am I now? What parts of me endure, and what is lost. How did I form my identity, and what remains?

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Bill Viola, Three Women, 2008, Photo Kira Perov


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