A rough outline of how human memory works

The storage and recall cycle is basically the way we break down the process of remembering. There is a lot going on under the hood, but we’re explaining these here so that when we refer to them later they make sense. To be able to collect a memory, you have to be paying attention and be able to use your senses effectively. Encoding is the process by which your sensory input is transferred to a form that can be stored. This is roughly analogous to serialization. Storage is the process by which the encoded version of your memory is stuffed. Recall is the process by which you retrieve your memories for use. We’re simplifying this a lot, because there is an enough information out there just on this part of the process to make an episode of its own.

The different “levels” of memory. There is a lot more popsci here than either of us would like. The general concepts are correct, but things get complicated really quickly when you get into the low-level neuroscience behind this stuff. Short term memory is the capacity for holding, but not manipulating a small amount of information for a short amount of time, usually just for a few seconds. Working Memory is a cognitive system with a limited capacity for temporarily holding information available for processing. It’s important for reasoning and decision-making behavior. Long term memory is the stage of memory where knowledge is held indefinitely. Muscle Memory is a form of procedural memory that involves consolidating a specific task into memory through repetition. This kind of memory is in play when you are learning things like playing an instrument, learning a foreign language with sounds that your native language lacks or performing in sports.

Your neural architecture (drastically simplified). The neurons in your brain and the connections between them are the storage location for your memories. Nerve cells connect with each other at a point called a synapse, which is where electrochemical pulses leap the gaps between cells. These connections change continuously in response to stimuli. The more a connection is used, the “stronger” and more permanent it becomes.

Lifestyle fixes that you need.

Lack of sleep will destroy your ability to remember things in general. Some research has shown that sleeping shortly after learning new information helps with retention, including over the long term. There are even some people who swear by learning DURING sleep. To test this out, scientists played a sound along with a pleasant smell while people were sleeping. When the subjects awoke, they started sniffing when they heard the sound. While this seems to point to something going on, it probably isn’t enough to validate the “bro-science” stuff about learning while sleeping. But it does mean that something useful is going on and that sleep is necessary for learning.

Exercise has been clinically proven to improve your retention of information. This is even true for older adults, as a 2013 study showed that after a fifteen minute exercise session, participants showed an improvement in memory and cognitive processing. Your diet impacts the rest of your health, so if your diet is bad enough, your health will also be bad enough to make it hard to learn anything. However, there are also some foods that are particularly bad for you. For instance, there is some indication that sugary drinks may contribute to a higher risk of dementia. This is true of refined carbohydrates in general as well. Trans fats, expecially the sort that are industrially produced (hydrogenated vegetable oils) increase the risk of alzheimer’s, damage memory, and contribute to cognitive decline. Overly processed foods in general are also not helpful, as they tend to have a lot of added sugar, transfats, and the like. Aspartame has been shown in a few studies to worsen performance on memory tests, but research is still ongoing there. Alcohol doesn’t help either, but you probably already knew that.

For a high degree of retention, focus on what you are learning, don’t multi-task by watching TV at the same time. While you can learn with background noise and other things going on (people do it all the time), you will make more effecient use of your study time if it’s the only thing you are doing. There are a huge number of studies backing this, and it’s also common sense.

The time of day matters as well. Declarative memory tasks (ability to recall exact details) are better in the morning. Semantic memory tasks (ability to tie what we are learning to what we already know) are better in the afternoon. The science is starting to lean towards the afternoons being better for studying as a result, with mornings being better for researching new information.

Caffeine helps too. A certain amount of caffeine will help you retain information, provided that you don’t overdo it. You also have to be careful of this if you are studying in the afternoon and are sensitive to caffeine, as it helps less than a good night’s sleep. If you screw up your sleep cycle, it won’t help at all.

Chunking

The simplest way to remember a sequence of simple facts is to break them into groups and then memorize the groupings. This is a good way to overcome the limitations of our short term memory because it reduces the number of “things” that you have to remember. This is why (for those of us old enough to remember…cough) people tended to remember local US phone numbers as three digits and then four digits, instead of as a seven digit string.

When trying to chunk, take the list of items that you need to recall and break them into groups. For instance, with vocabulary words, you might take words that share a context, and group those together. As you get used to chunking things, there is also a higher order improvement in your ability to chunk, increasing the number of things you can collect in a group. You might also do this with chord progressions in music. Instead of remembering individual notes, you remember sets of them. Combined with muscle memory, this tends to be the way a lot of musical types recall things.

Spaced Repetition

When trying to study things for recall, it’s far better to study with some gaps than it is to attempt to cram. Not only will this reduce fatigure, but you also need to regularly refresh information in order to keep it. The more frequently you encounter a piece of information that you have already encoded, the less often you need to refresh it to keep it encoded. As a result, having a regular habit of refreshing information that you are not constantly using, but will need, is a good idea.

The Leitner method for flashcards is a good example of this approach. Have a box full of flashcards, with several compartments, labeled numerically (typically 5). If a flashcard is new, it goes into compartment 1. If you know the material well and the card is in compartment 1, it goes into compartment 2. The process repeats for each additional compartment, for as many compartments as you have. You review the cards in the first compartment daily, the cards in the second comparment every other day, and so on. The idea basically is that as you internalize information, you review it less often. Automated versions of this approach are used in a lot of spaced repitition systems.

Memory Palace Method

Another approach is to tie your memory of things to spatial concepts. It turns out that our long history of being hunter gatherers makes us have very good memory in regards to spatial concepts (because getting lost was fatal for most of our evolutionary history). As a result, if you can tie something you are learning to a spatial concept, you can often remember things better.

Pick a place that you know well, and plan a route through the area. Take the list of things you want to memorize and place them mentally at locations along the route. Try to exaggerate the items and make them interact with the environment in your mind. The idea is to tie these things to your existing memory of that particular location. Don’t be afraid to be weird or humorous. This will enhance your ability to remember the information. Write the stuff down, then walk back through the scene in your mind repeatedly.

Associating Items with things you already know

If you’ve already got related information in long term memory, it’s a lot easier to tie other things to it. One example of this is that everyone can remember the shape of Italy, because it is shaped like a boot. Unless you are in that part of the world, you likely don’t remember the shape of Ecuador (shaped a bit like a dove flying to the right). This is also why we use analogies so much on this show – it’s because it’s a way of implanting information by tying it off to something else you already know.

Basically take a mental image of something you know, and then mix in the thing that you are trying to learn.

Acronyms and other Mnemonics

Similarly, you can remember a sequence of things by remembering acronyms for each of the items in sequence. This is often referred to as a mnemonic. This takes advantage of the way the human mind tends to do better at remembering certain kinds of things, such as musical jingles. Most of us in the United States learned things such as the states in the country, the planets in the solar system, and the way biological categorization works using Mnemonics.

Med school students seem to really leverage this stuff a lot. This tends to be a winning strategy when someone needs to memorize a lot of lists and processes.

Tying things to visual indicators

You might also tie things to something visible. For instance, if you are learning a foreign language, you might stick post-its on everything in the house with the word for that thing in the other language.

The idea here is two-fold. It directly ties memories to physical objects, and it will cause repeated exposure at intervals. This will not work very well for abstract concepts, but it does well for physical ones. It’s essentially a memory palace, except you live there.

Write by hand instead of typing

When collecting new information, retention is improved by writing it out by hand instead of typing. Writing by hand also tends to force you to summarize what you are learning, which is better for recall, since you probably can’t handwrite things as quickly as you can receive the information, which is not true of typing. When typing, it’s easier to transcribe without really listening and processing the information.

These things even hold true for situations where you are studying video courses and able to pause. There was a study a while back where half of the students in a class were told to use computers to take notes, while the other half used handwritten notes. The students had similar levels of recall for the information in the class, but the students who used computers to take notes had much poorer performance on conceptual questions.

Teach other people

To really get a deep understanding of something to the level that it is instinctive, try teaching other people. This podcast is a great example of this principle in action. We both have learned and internalized a lot of things from having to package information up in a form that you can consume. For instance, while we often come up with analogies on the fly during the show, we often remember things we have covered based on the analogies we came up with as we were talking.

Because you must summarize and organize information when communicating with other people, you are forced to work to both organize the information and express it in an appropriate manner. This is one of the hidden benefits of conducting a lunch and learn – you’ll often get a much deeper understanding of the material by teaching than you will by being one of the learners. This approach also neatly and automatically forces you to engage in the activities that help you retain information, as discussed earlier.