Memory: How do our Brains Encode, Store, and Retrieve Information?

Have you ever wondered why memorizing the quadratic formula always takes such a herculean effort, yet you can recall Taylor Swift’s entire 1989 album lyric for lyric? Or how you can confidently describe a visceral memory from your childhood but somehow can’t recount what you had for breakfast yesterday? From computers to the human mind, memory possesses a highly complex role. It is the process of retaining knowledge over a period to affect future actions. This article will delve into the different types of memory involved and how our brains encode, store, and retrieve information.

How is memory classified?

Memory can be categorized into two types - explicit and implicit. Explicit memory can be recollected by conscious effort and is stored in the medial part of the temporal lobe of the cerebrum and hippocampus. It can be subdivided into episodic memory, which recalls personal events and individual experiences, and semantic memory, which recalls general and/or autobiographical facts.

In terms of implicit memory, this is memory recollected unconsciously. Procedural memory falls under this category; this is the process of retrieving information necessary to perform learned skills. Thus, it is often called non-declarative. It is stored in various regions of the brain such as:

• Cerebellum

• Neocortex

• Striatum

• Amygdala

So, memorizing the quadratic formula or knowing 1989’s album by heart are distinct examples of semantic memory. On the other hand, recounting a childhood memory and your meal for breakfast can be classified as episodic memories.

What is the multi-store model of memory?

Proposed by Atkinson and Shiffrin, the “multi-store model” or “modal model” states that memory is made up of three distinguishable components:

• Sensory register

• Short-term store

• Long-term store

The sensory register takes in the data from our environment and what our senses note. The short-term store, known as short-term memory (STM), receives and holds input from both the sensory register and the long-term store. Finally, should the information be rehearsed in the short-term store, it will then be transferred into the long-term store, where it will be held indefinitely.

How does memory encode, store, and retrieve?

Memory consists of the following steps:

• Encoding

• Storage

• Recall (retrieval)

Encoding can be defined as the process of changing the material heading into our nervous system into a mode. This is so the system can manage the information more easily. Therefore, it can be easily stored. There are several methods through which knowledge can be encoded through visual, acoustic, and semantic coding. Acoustic encoding lets the brain hear the sounds associated with an unfamiliar concept. Contrastingly, semantic coding inserts a new concept into a realm of context, which helps us comprehend the purpose of this new concept. While short-term memory is encoded predominantly with acoustic coding, long-term memory usually involves more semantic coding. Nevertheless, long-term memory data can also be encoded via visual and acoustic coding.

So, how do our brains acquire such data from these storage systems? The process of retrieval emerges into the picture. When we struggle to remember information, this can be attributed to the inability to retrieve that information. This is where the dissimilarities between short-term and long-term memory are brought to light. Short-term memory is stored and retrieved chronologically. However, the storage and retrieval of long-term memory occur by association. The organization of information can thereby facilitate the process of retrieval.

How does the working memory model operate?

Let’s explore short-term memory in more depth. The Working Memory Model, devised by Baddeley and Hitch in 1974, explains short-term memory as a system with multiple components. It comprises the central executive and the visuospatial sketchpad. The central executive dictates attention and coordinates the phonological loop, which handles auditory information, while the visuospatial sketchpad processes visual and spatial information.

In the words of Kandel, “We are who we are in great measure because of what we learn, and what we remember.”

Works Cited

Anon. Procedural Memory - an overview, [online] sciencedirect.com. Available at: https://www.sciencedirect.com/topics/neuroscience/procedural-memory#:~:text=a%20Procedural%20Memory,to%20read%20mirror%2Dreversed%20text.

Mcleod, S. (2022), Working Memory Model (Baddeley and Hitch), [online] Simply Psychology. Available at: https://www.simplypsychology.org/working-memory.html 

Foster, J.K. (2002), The Oxford Handbook of Memory, [online] Brain. Available at: https://academic.oup.com/brain/article/125/2/439/297017

Swaleha, M. et al  (2021), Memory: Neurobiological mechanisms and assessment, [online] Industrial Psychiatry Journal. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8611531/