The widely accepted definition is that memory is the faculty of the brain which allows us to encode, store, retain and later recall information. Psychology Today describes it as "a record of experience that guides future action": an interesting but truthful way of putting it. We often take memory for granted, but without it we would fail at basic everyday tasks such as brushing our teeth, making breakfast, and walking to the bus stop.
How does memory work?
Nerve cells in the brain (neurons) communicate with one another through synapses (a type of neural fabric which passes signals between neurons). This happens when neurotransmitters (chemicals which allow transmission of these signals) are present. The strength of the connection between neurons determines how well a memory is formed. The persistent strengthening of the synapses is a process known as long-term potentiation, or LTP. LTP is considered the neural mechanism which explains memory because the process changes the strength of the connection between brain cells. If the connection remains strong, the ideas stored will be retained.
Our ability to recall memories depends on the strength of this connection. When the synaptic connections between neurons are used, they become stronger. This is why repetition is considered such an effective tool for memory and recall. And it works both ways: when these connections are not used, they will deteriorate, and it becomes harder or even impossible to employ them for recall.
How can I improve my memory?
Fortunately, such is the value and utility of memory, the scientific literature on it is broad and in depth. One collaborative study undertaken by Heriot Watt University tested the effect of minimal interference on recall, i.e. avoiding doing things which might interfere with memory formation. In the study, two groups of participants were told two stories. The first group then played a spot-the-difference game, whilst the second group were prescribed ten minutes of "wakeful resting". The second group showed a significantly enhanced ability to remember the story, both immediately following the resting period and after being tested again a week later. These striking results have been found to come down to increased communication between the hippocampus and visual cortex during periods of rest. Thus, we may conclude that intermittently reducing cognitive stimulation while trying to memorise information allows memories to form better. By extension, you may benefit from periodising your revision blocks rather than cramming your work into one long continuous slog.
Columbia University's department of neurology cite three techniques to help you remember ideas: visualisation, association, and organisation. An example of visualisation is attaching an idea to an image: just like how seeing a photo of someone's face can trigger the memory of their name. Association entails connecting something you're learning with something you already know: for example, if you're trying to remember the street where your friend lives, you could start calling her in your head Jane "Bolton Street" Harris. Lastly, organisation can be utilised by grouping separate ideas into categories. So, if you want to remember a list of physics equations spanning different fields, you might choose to group them into fluids, forces and thermodynamics.
Mnemonics have long been cited as a useful device for memory encoding and recall. This is because they give you a simple, memorable way of organising and structuring information. For example, whilst trying to learn William James' four features of religious experience, I tied the properties ineffable, noetic, passive and transient together into PINT. Notice how this mnemonic utilises all three of visualisation, association and organisation. Just having the first letter of each property as a prompt made them incredibly easy to remember, and from there I could go on to elaborate and explain what each property signified. A study testing the benefits of using mnemonics to learn vocabulary terms found that 81% of students felt it helped them learn words faster and 66% of students could learn more words overall.
Finally, keeping the four pillars of general wellbeing in good order will make a significant difference to your memory ability. This means getting exercise, eating healthily, managing stress effectively and sleeping well improves your efficacy at retaining and recalling info. It is scientifically proven that taking care of these four pillars will improve memory and cognition - even at cellular level. I have discussed the relationship between cognition and diet, exercise and stress in previous articles, which are linked below. Thanks for reading and good luck!