Welcome to part two of our practical and theoretical guide to memory. Last time we introduced some of the more technical aspects of memory and the corresponding areas of the brain to contextualise this complicated topic. This time we look at the three theoretical stages of memory formation.
How to Access Long-term Memory Storage?
While short-term memory has a small, finite capacity (seven plus or minus two is the magic number) and a short shelf-life (around 30 seconds), long-term memory knows no bounds. We haven’t yet reached the limits in terms of capacity or time for long-term memory. Here’s how we access it:
Step One: Encoding
Encoding involves taking a sensory input and converting it into something the brain can deal with; the three principal ways of encoding information are visual, acoustic or semantic. Visual involves taking a kind of memory snapshot. Acoustic could be repeating an audible pattern for a phone number. Semantic involves converting sensory input into meaning. Semantic encoding has been outlined as the primary encoding system for long-term memory; this means understanding a concept is often the first step in unlocking long-term memory.
Further advice in the encoding stage is to relate information to wider events as associations can aid in later recall. Imagining events has also been employed as a semantic strategy that aids in recall. Recoding, or encoding further information about a topic already studied, has also been suggested as a viable option; this carries the bonus of potentially aligning two previously unconnected memories which can improve recall of both. However, it’s worth noting that associations, imaginations and recoding can also imprint over memories, leaving us with a false version of events.
Step Two: Storage
Each time we encode an experience, the chemistry of the brain changes. Experiences create physical memory traces in the brain through a process called consolidation. We use these memory traces to reconstruct past events or information alongside our current belief of what we encoded; this is how we store memories. Memory is, therefore, formed of memory traces and current beliefs of the event as opposed to being a perfect reproduction of events.
Retroactive interference can provide obstacles to accurate recall; this refers to new events that may interfere with the information we need to recall between when it is encoded and stored, and when it is needed for recall. Imagine learning about eight world leaders over a period of two weeks; you have a test on one leader at the end of the two weeks, but information regarding the other seven finds its way into your examination paper: this would be an example of retroactive interference.
Step Three: Retrieval
Without retrieval the first two stages are useless. Although we encode huge amounts of information daily, it’s unlikely we’ll ever use any of it. Those memory traces created quickly fade never to be recalled. Instead, we want important information in our long-term memory to be what’s called available memory. Unfortunately, the science of available memory is still being developed; there’s still much we don’t know about recalling memories. However, there is an encoding specificity principle which has been identified as one of the most important elements behind retrieval cues which can be hugely beneficial in understanding why some memories stay with us for life. By encoding information in a very specific, complex way, which overlaps with the sensory input of an experience, it would appear more synaptic connections are made that engage with several areas of the brain. A small, yet very specific cue could lead to a complex experience in which much information can be recalled. It may seem obvious, but cues should not match with too many experiences as overlap can occur.
Join us next time on our memory guide where we will be giving you our top tips for getting the valuable information into your long-term memory!