By Peyton Grantham
Imagine yourself sitting in math class learning the Pythagorean Theorem. You might have spent hours upon hours studying and using the theorem to understand it. Doing this may have exercised your brain so much that you still remember the formula in your long term memory. This is what memory consolidation is for.
What are Memories?
Memory is defined as retrieving information, storing said information, and then remembering it at a later time (1). Memory involves various parts of the brain, but the hippocampus is a big part of that. The hippocampus is situated between the brain’s temporal lobes and takes a huge role in memory and emotions. When we take in information, the data goes through the brain using neurons, synapses, and neurotransmitters. The neurons communicate with one another through electrical and chemical currents and the synapses are a small space on a neuron that allows information to be passed on to other neurons, through this process neurotransmitters help by TRANSMITTING chemical signals that move the data along into storage. Through these chemical signals, memory is created. Memory consolidation causes short term memories to be stored as long term memories.
Sensory Memory
Sensory memory is the first step in memory consolidation. This is the information collected by your brain. This could be the taste of a green apple, the smell of your favorite pie, the touch of a cozy sweater, the sound of a favorite song on the radio, the sight of the ocean, etc. This process allows you to recall all of those sensations. Paying attention to detail allows you to possibly store this in your short term memory (2).
Short term Memory
Short term memory is a storage unit meant to hold a small amount of information for a short period of time. For example, if someone was reciting a phone number, immediately afterwards you might be able to recall that number and write it down, but this information would soon go away and you are bound to forget a number or two. This is short term memory. It is either stored in long term memory or it is gone and out of your brain (3).
Long term Memory
Long term memory is the last storage unit in memory consolidation. This storage unit has been filtered down to the important things, like knowing the number 867-5309 from “Stacy’s Mom”… super important! Long term memories are the songs sung on repeat, the information relayed multiple times, the good days you think about over and over and over again. This information can be maintained for long periods of time, and some, for life. There are two types of long term memory: explicit and implicit memory. Explicit memory contains both episodic and semantic memory. Episodic memories are memories about personal experiences like the time, place, and event. This includes anniversaries and other important dates to remember. We can do this by either thinking of it constantly, or putting it into practice. This can be you wanting to remember the best day of your life, like an engagement, the time you brought your first child into this world, your wedding, birthdays, etc. This can also unfortunately include horrible days, like what you were doing during the terrorist attack on September 11th. Semantic memory is our general world knowledge like concepts, facts, and the languages we know. Implicit memory encompasses all unconscious memories and skills like motor memory (4). Implicit memory ranges from singing a familiar song without realizing that you are doing so, typing on a keyboard, riding a bike after years of not doing so, writing with a pencil after college break, etc.
Memory Consolidation
This brings us to the final step, memory consolidation. Memory consolidation is somewhere in between short term and long term memory. In this process short term memories are stored into long term memories by chemical changes in the nervous system. This occurs through retrieval in the hippocampus of the brain. Rumors in the psychology field have stirred that REM sleep cycles allow for memory consolidation. Studies actually show that this is not true. It has been discovered that REM sleep plays a massive role in the processing of procedural memory, but there is no role in the formation of explicit memories. These studies have issues due to high stress of the participants involved, and therefore it is hard to be absolutely certain (5). Psychologists go back and forth on this topic and speculate what may or may not be true.
(1) Dean, M. E. (2019, May 5). Memory consolidation: Psychology, definition, and examples. BetterHelp. Retrieved November 29, 2021, from https://www.betterhelp.com/advice/psychologists/memory-consolidation-psychology-definition-and-examples/.
(2) Perera, A. (2021, February 1). Sensory memory. Sensory Memory | Simply Psychology. Retrieved November 25, 2021, from https://www.simplypsychology.org/sensory-memory.html.
(3) Cowan, N. (2008). What are the differences between long-term, short-term, and working memory? Progress in brain research. Retrieved November 24, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2657600/.
(4) Camina, E., & Güell, F. (2017, June 30). The neuroanatomical, neurophysiological and psychological basis of memory: Current models and their origins. Frontiers in pharmacology. Retrieved November 25, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5491610/.
(5) Rasch, B., & Born, J. (2013, April). About sleep’s role in memory. Physiological reviews. Retrieved November 25, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3768102/.