Semantic encoding is when these sensory inputs are then associated with a specific meaning. Multiple studies have demonstrated that attaching meaning to new information (encoding them semantically) improves recall. For example, associating a disease with a specific patient you have seen with that disease will help you to remember key aspects of the disease.

Information is initially stored in short-term memory, or working memory. This form of memory has a relatively small capacity of approximately five to seven items; more information can be stored using chunking (e.g. grouping numbers together in a phone number). Short-term memory is only stored for a short period of time, thought to be between fifteen to thirty seconds. An item may be kept in working memory for longer using rehearsal (e.g. repeating a phone number over and over). Counting backwards in 3s (the Brown-Peterson technique) is a way of ensuring that items do not remain in short-term memory, by preventing rehearsal.

The retention interval is the period of time between learning information and being asked to recall it. During this time, information is consolidated; this particularly occurs during idle time and during sleep. Consolidation may be disrupted by learning new information. For example, if you were to participate in a resuscitation of a cardiac arrest and then debrief about it, hearing others' accounts of the incident can disrupt your own recollections of the incident. This is known as retroactive interference.

Repeated retrieval of information can strengthen connections and solidify memories. This is the underpinning concept behind the benefits of self-testing using memory devices, questions and flashcards.

Interestingly, repeated retrieval can also alter memories and make us put weight on certain aspects while underplaying others. Similarly, retrieving distant memories can cause them to be altered. For example, an often-told funny story can slowly change over multiple retellings until we ourselves believe the current telling to be a true recollection of events.

Based on the concepts above, there are several things that you can do in order to improve recall.

If you're writing notes digitally, consider using a bad font such as Comic Sans or Bodoni MT - two studies suggested that using such fonts improves recall. This is thought to be due to the difficulty of reading the notes, resulting in more mental work and more active attention.

Consider using the pomodoro technique - focused studying for twenty-five minutes, followed by a five-minute break. During the break, reward yourself with something small, such as a snack, song, video or moment of mindfulness. This cycle can be repeated, using a timer to ensure that you keep to the schedule.

Naps can also be useful for consolidating connections between ideas. In one study, a 90-minute nap was associated with greater associative memory (remembering word pairs) but not item memory (remembering individual words) when compared to not taking a nap.

A commonly used mnemonic device in medical school is acronyms. . Acronyms use the first letter of each word to create a shortened representation that can then be used to jog your memory about each item on the list. For example, the ESCAPPM organisms are organisms with inducible beta-lactamase activity that is chromosomally mediated, meaning that they can initially appear sensitive to beta lactams and later become resistant. The acronym stands for: Enterobacter, Serratia, Citrobacter freundii, Aeromonas, Proteus, Providencia, Morganella morganii.

Expression mnemonics are also commonly used in medical study. This involves the creation of a sentence using the first letters of each word. An example is the cranial nerves:

This is a mnemonic to remember: Olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accessory, Hypoglossal.

What a memorable sentence!

More objects can be placed in different places (e.g. above the fireplace, next to the doorway) and the room can become more full with items - at times the method can be used to remember hundreds of words.

When you need to recall the information, imagine walking through the room and seeing the objects you placed - hopefully each object will remind you of the word you have associated with it.

More comprehensive guides to using the memory palace are available if you would like to learn more about this method.

Concepts can be more difficult to commit to memory, particularly if the concept is complex. Several methods may be used to optimise our recall of concepts.

In a study of nearly two hundred adults, those who learned information using analogies performed superiorly in immediate and delayed recall when compared to those who learned without analogies (Halpern). Those who learned using analogies were also more likely to be able to infer new information about the topic, and create their own analogies about it.

Creating a mindmap about a topic can improve our overall understanding of the structure of the topic, and leave an imprint in our minds that can stimulate recall. In order to improve recall, try redrawing a mindmap from memory and then comparing your copy to the original mindmap.

One of the more effective ways of improving your memory of a topic is to test yourself. Retrieving a topic from your memory repeatedly (known as practicing retrieval) improves learning more than just studying the same information over and over (Karpicke & Blunt). 

By reviewing information multiple times, we are less likely to forget it over time. This repeated review and recall cycle works best if each review is spaced out in time, rather than reviewing the same information multiple times in quick succession (Karpicke & Bauernschmidt). Ideally each review should happen when we're about to forget the information.

The benefit of teaching others extends to expecting to teach - in a study of students learning written material, recall was improved when students were told that they would be teaching others, compared to being told that they would take a test on the subject. 

If you don't have any opportunities to teach, try using the Feynman technique. This involves imagining that you are trying to explain a concept to a twelve-year old child. Use the simplest language you can, and illustrate the concept using analogies and metaphors. This can help to solidify the concept in your long-term memory.