Why is it that I can remember the words to some random song that was popular decades ago, but I can never remember what the article said about the foods with the most pesticides that I just read yesterday and a dozen times before that? Memory is a strange thing.
How Something Gets Filed In Your Brain
Learning (or the opposite, forgetting) occurs in your brain through what’s known as the information processing system. All incoming stimuli, everything you see, hear, or smell, goes first into short-term memory (STM), which is similar to your email inbox. Information is held here for a matter of seconds before it’s either attended to by working memory (WM) or discarded. Unless you make a specific effort to notice and record information, a large portion of what’s taken in by your brain is never processed and learned.
Info that you attend to gets moved from STM to WM, which is the active part of the information processing system. This is where conscious thinking and remembering happen. In about 5 – 20 seconds, your WM screens and decides how to handle the stimuli. Information must be processed before it can be transferred into long-term memory (LTM).
Information enters LTM from WM and must be classified, organized, and stored. Information can be committed to LTM through repetition, such as studying for a test or repeatedly going through the steps of tying your shoes, or associating it with material already in LTM. The three main activities of LTM are storage, deletion, and retrieval. Information retrieval can take the form of recall or recognition. In recall, information is reproduced from your brain. With recognition, you know that you’ve seen the information before and are familiar with it.
Some memories, such as those about events and facts, are available to your consciousness in what’s called declarative or explicit memory. Then, explicit memories are classified as either episodic or semantic. Episodic memory is specific to an individual and contains the personal details about the events of their life. Examples are:
- Recalling where you were when you heard about the 9/11 attacks
- Reminiscing about your first kiss
- Knowing the name of your childhood pet
- Remembering your wedding day
- Knowing the name of your roommate your senior year in college
Semantic memory is the recollection of common knowledge accumulated over our lives. They’re the indisputable bits of information not attached to emotion or personal experience. Some examples are:
- Knowing that the sky is blue
- Recalling that Washington, D.C., is the capital of the U.S. and that Washington is a state
- Knowing how to use utensils
- Understanding how to put words together to make a sentence
- Knowing how to use a phone
There’s a continual, steady progression of memories from episodic to semantic, especially during childhood when you’re continuously learning new things, but not all semantic memories begin as episodic.
Another kind of memory, implicit or automatic, isn’t available to your conscious mind. Implicit memory uses past experiences to remember things without actively thinking about them. It allows you to use a previously learned skill, like riding a bike or driving a car.
One kind of implicit memory, procedural, is acquired through repetition and practice of motor skills and is sometimes referred to as muscle memory. Once something is learned, you can perform the actions on autopilot.
Implicit memory also includes the subconscious emotional content filed away over our lives that has a huge impact on our mindsets and perceptions of the world.
In the book, Rewire Your Brain for Love: Creating Vibrant Relationships Using the Science of Mindfulness, Marsha Lucas, PhD, calls implicit memories the “unthought known” and labels them the “unconscious effects of your past experiences.” Implicit memories are the “nonverbal recordings” formed when your brain’s hippocampus isn’t brought online to consciously organize information. Lucas writes:
These memories got quickly and permanently stored, even though you don’t have conscious awareness of them as memories – they’re just kind of ‘in there,’ informing and influencing you without any kind of time stamp, and without your being aware of their influence.
Explicit and implicit memory are independent of each other, which leads neuroscientists to believe that there are separate mechanisms for each employing different brain areas. For example, people with impaired explicit memory can have completely normal procedural memories and vice versa. The cerebrum and hippocampus are integrally involved in explicit, and the cerebellum and amygdala in implicit.
Both Are Neuroplastic Processes
Learning and memory are neuroplastic processes in your brain, meaning they involve chemical and structural changes. By altering the number or strength of connections between brain cells, information gets written into memory. It’s not really known exactly where or how the filing and recalling of memories happen, but the most popular candidate site for memory storage is the synapse, the space between neurons, where they communicate.
In other words, a memory is believed to be a particular pattern of activity at synapse sites. Studies with mutant mice, called “knock out mice” who are genetically engineered to have inhibited plasticity, support this theory.
This means that when you repeatedly practice an activity or access a memory, your neural networks are physically shaped accordingly. For example, professional musicians’ brains have more gray matter than non musicians. When you stop performing a behavior or recalling that memory, your brain eventually prunes the connecting cells that are no longer in use. This can work both for you and against you and is your chance to sculpt your brain.
Many factors affect your ability to learn and form new memories. Prior knowledge and motivation play a huge role. The more information already in your brain with which to associate a new factoid and your interest in it improve the chances of something being remembered. Lack of sleep, stress, depression, and other physical issues, such as diet and,thyroid function, can drastically impair memory. Eating foods that support your brain, exercising, meditating, having novel experiences, and challenging your brain can improve memory.
Here’s lots of good info from Harvard Health on how to build your brain’s memory and below is a neat infographic with some cool ideas to enhance learning.
image source: https://unsplash.com/photos/ICW6QYOcdlg