We Thought We Understood How Memories Work; We Might Be Wrong

memories

[DIGEST: PBS, Science, Science, Science, JAlzheimer’s, NeurobioAging, SciRep]

There are two types of memory: short term memory and long term memory, right?  Short term memory includes things like the phone call we just finished, what we had for breakfast, and who is picking up the kids today.  Long-term memory is the face of our best friend from third grade, whether we paid our taxes on time last year, or the names of the bones in the human body from high school biology class.

For 50 years, researchers have talked about how memories are formed in the hippocampus and later move to the cortex for long-term storage. It turns out this may not be exactly true.

An April 2017 article in the journal Science found that our brains make two copies of each memory the moment they are formed. We file one away in the hippocampus, the center of short-term memories, while we store the other in the cortex, where our long-term memories reside.

With the new theory, both the hippocampus and the cortex are important to memory but their link or connection is the key. Takashi Kitamura et al discovered that at the onset of learning, the neurons involved in memory formation, both short term and long term memories, are quickly activated not only in the hippocampus but in the prefrontal cortex as well. When the memories include an element of fear, this process also depends on the activity of nerves from both the hippocampus and the amygdala, an emotional player in memory formation.

Over time, the cortex’s prefrontal neurons consolidate their role in memory expression. In contrast, the hippocampal neurons slowly lose hold of that particular memory. Over time, long term memories are stored while short term memories diminish, but both types of memories have existed in the hippocampus and prefrontal cortex from their creation.

In addition to its memory function, the prefrontal cortex located in the forehead area of the brain is involved in decision-making, including remembering best decisions in the past or learning from mistakes. This is why we can sometimes get into a better relationship and stop repeating the same mistakes over and over again. The prefrontal cortex is like the boss of a large corporation driven by reason, logic, problem-solving, planning and memory. 

The amygdala is the key emotional center of the brain. It also is part of the limbic system, which ensures our survival. Trying to reason with the limbic system is like shooting a lion and then trying to apologize to it. The amygdala sits next to the hippocampus near the

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We Thought We Understood How Memories Work; We Might Be Wrong

by Kimberly Burnham time to read: 3 min
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