Differences Between Short-Term Memory and Working Memory
Are you aware of the differences between short-term memory and working memory? We all have memory, but defining it and understanding the processes underlying it is a real challenge. As difficult as it may be to circumscribe, it’s easy to come to the conclusion that memory is an integral part of human beings: It not only allows us to remember events but also to transmit them to other generations and build a culture around them.
Memory has allowed us to advance as a civilization and as individuals, scientifically, ethically, and morally. Without it, we’d surely be no more than primal beings subject to the vagaries of natural selection. With this exciting premise in mind, we’ll show you the differences between short-term memory and working memory. You’ll see that they’re not the same thing.
What is memory?
The organization Hipocampo.org defines memory as “the mental capacity that enables the subject to record, preserve, and evoke experiences (ideas, images, events, and feelings).” In other words, it’s a brain function that allows humans to encode, store, and retrieve information from the past.
Various brain areas are involved in memory: The hippocampus, the amygdala, the striatum, the mammillary bodies, and many other structures are involved in specific types of memorization. For example, the hippocampus is linked to declarative and emotional memory.
As the University of Queensland indicates, memories are formed when a series of neuronal groups are reactivated in the brain. This occurs when we’re exposed to a series of stimuli or specific successions, which activate neuron pathways that become more or less strong according to the requirements.
The term synapse refers to the functional junction between two neurons or a neuron and a different cell body. The most basic theories of memory defend the idea that the more a specific synapse or neural communication path in the brain is strengthened, the more likely we are to remember. Long-term neural stimulation (or the lack of it) could explain what we do or don’t remember.
Remembering events strengthens the neuronal synapses responsible for giving us their memory. This is achieved through a very complex process known as synaptic plasticity, which we’re not going to develop in this article, but the central idea is simple: The more intense the stimulus or the more we have to use it, the better we’ll remember it.
Phases of memory
Human beings learn and relate to the environment based on 3 main processes: Perception, learning, and memory. In other words, we have to be able to receive external stimuli, recognize them, and ultimately assign meaning to them and remember them in the short or long term.
Memory allows us to collect new information, organize it so that it makes sense (from both an objective and subjective point of view), and retrieve it when necessary. This is achieved thanks to 3 simple steps:
- Coding or registration: Consists of the transformation of stimuli into a mental representation. In other words, human beings attribute recognizable and manipulable elements by memory to perceived sensory information (words, numbers, images, and figures).
- Storage: This refers to the retention of the transformed information for its later use. Schemas, categorization, and establishing relationships go a long way in storing knowledge.
- Recovery: This is the act of remembering. We navigate our minds and collect what we’ve learned when we need it. In other words, we bring previously encoded and stored information into our consciousness.
What are the types of memory?
Once we’ve learned what memory is in general terms, we’re ready to dissect the differences between short-term memory and working memory. In any case, we find it interesting to cite (albeit briefly) all the subtypes included within this term, as it’ll be useful to establish comparisons later on:
- Sensory memory: This is the ability to retain impressions of sensory information after the original stimulus has ceased. It allows us to save the sensations that our senses generate when detecting the environment, such as a smell, a tactile signal, or a sudden sound. It stays for about 300-500 milliseconds.
- Short-term memory (STM): This is the type of memory that retains a limited amount of information for a fairly short period of time. It allows you to retain (but not manipulate) what’s remembered. Its maximum duration is about 30 seconds.
- Working (or operational) memory: This is an active process that allows working with the information held by the STM.
- Long-term memory (LTM): This is the brain mechanism that allows us to encode and retain a practically unlimited amount of information for a long period of time. The operating interval can be from a few seconds to several years.
More than watertight memory types, it is necessary to see each of the variants as part of an assembly line. Sensory memory “collects” the stimulus, the MCP retains it for a short period of time, the operative “works” with it (or not) and the MLP stores it in the long term if the information received is valuable. Otherwise, it is quickly forgotten.
The intensity and usefulness of the information perceived are essential determinants for it to be stored in the long term.
The differences between short-term memory and working memory
We’ve named both terms above, but now we’ll show you their differences at length. Although these two types of memory are part of the chain leading to the long-term variant (LTM), they can’t be used interchangeably. Now you’ll see why.
1. Short-term memory doesn’t manipulate information
Short-term memory is like the ability to retain, but not manipulate, a small piece of information for a short period of time. The memory is in an available state for about 15-30 seconds, as indicated by the Simply Psychology portal.
On the other hand, working or operational memory is the set of structures and processes that allow temporarily keeping information active, making it possible to process and manipulate it. This variant participates in a very significant way in functions such as reasoning, planning, and decision-making.
One of the main differences between short-term memory (STM) and working memory is that the latter retains information in order to manipulate it. Not all stimulus collected by the STM is used for work, but all stimulus worked must have passed through the STM before.
Working memory allows the manipulation of the stored information. It represents a step that goes beyond short-term memory.
2. Different durations, but at the same time, similar
As indicated by sources already cited, short-term memory has an average duration of about 15 seconds and a maximum of 30, although perhaps somewhat less. For example, we can remember any letter for an interval of 7.3 seconds and a number for 9.3 (on average). However, the items stored in the STM can be kept longer by repeating them verbally (phonological loop).
The simplest example to understand a phonological loop is when we’re told a telephone or identification number. We always tend to recite it out loud, as subvocal repetition helps us a lot to not forget recently learned concepts quickly. If there’s a distraction during the loop, the person will most likely forget the information.
At the same time, working memory has an interval of 10-15 seconds to “decide” if that information is going to be used repeatedly or not, but it can manipulate the concept for a longer time. For example, a person exercises their working memory when they memorize a geographic address (STM component) while attending to addresses in order to reach it (operational component).
The duration of working memory is less fixed than that of short-term memory, set at an interval of up to 30 seconds.
3. Different functions
Another essential difference between short-term memory and working memory lies in the function of each. Again, we’ll better understand each with easy examples:
- A person memorizes a maximum of 7 digits quickly and reinforces the information learned with a phonological loop. They’re using short-term memory.
- Someone else performs the same exercise but then has to repeat that number concatenation in reverse. Here, they must make use of working memory, as they’re manipulating the information to generate a new order.
There are many more examples that help distinguish functionality between one type of memory and another. A student who’s listening to a syllabus may try to memorize it immediately (STM component) or may try to understand and internalize the information received in a broader context. As you can imagine, this last person mainly puts their working memory into practice.
The functionality of each type of memory is clear after exposing these scenarios: The STM allows us to evoke information that we’ve just recorded in a very short time interval, while working memory is used to solve problems, obtain results, and integrate complex concepts.
Neither is more important than the other. For working memory to exist, short-term memory has to be there.
4. Working memory is more complex
Baddeley’s multicomponent model explains the functioning of the human mind, specifically working memory, through a series of hypotheses. Its components are the following:
- Central executive system (SEC): This is a cognitive and processing control center that guides behavior and that involves interactions between the various mental processes. It includes such complex concepts as perception, motivation, attention, emotions, and memory.
- Phonological loop: As we’ve said in previous lines, this is a system that temporarily stores information in a verbal format.
- Visuospatial Agenda: This is a system that feeds on images and works with them temporarily. It’s very useful when it comes to locating ourselves in a three-dimensional space.
- Episodic buffer: This is a storage center that holds the inputs of the visuospatial agenda and the phonological loop. It interacts with long-term memory.
The representation of this multi-component model shows us that, indeed, working memory is much more complex than short-term memory. This operational variant is launched when the information to be kept or the task to be carried out is of such complexity that it saturates the cognitive system. At this point, short-term memory is no longer as useful.
Starting working memory is a challenge for human attention. This involves memorizing, integrating, and manipulating, while CCM is only based on retaining in a concrete and brief way.
5. Working memory isn’t always present but short-term memory is
The last of the key differences between short-term memory and working memory lies in their essentiality when it comes to integrating information. As we’ve seen in previous lines, the “assembly line” that leads us to memorize something follows this order:
- Sensory memory
- STM or short-term memory
- Work memory
- LTM or long-term memory
However, it should be noted that in some cases, the working memory step can be skipped. If we don’t have to manipulate the information received (organized it, change its meaning, or apply it immediately), this cognitively demanding process ceases to make sense at that moment. We can carry out a sort of bypass and access (or not) the LTM.
On the other hand, there’s no creation of new memories without the STM. If we’re not able to store the stimulus for 15-30 seconds, it can’t be understood and categorized in the long term. In any case, and on a theoretical level, a person with short-term memory problems could remember those established in the long term earlier in their life.
The differences between short-term memory and working memory: More than it might seem
The differences between short-term memory and working memory are more apparent than some authors suggest. Although they’re sometimes used as interchangeable terms, it’s important to recognize that working memory goes a bit beyond STM, as it manipulates information rather than just storing it.
Although it seems that working memory is more important than STM, it must be borne in mind that without the latter, the creation of new memories is practically impossible. In the end, each and every one of the subsystems responsible for maintaining our memories is essential for different moments in our lives.It might interest you...
- Memoria, Hipocampo.org. Recogido a 30 de octubre en https://www.hipocampo.org/memoria.asp
- How are memories formed, Queensland University. Recogido a 30 de octubre en https://qbi.uq.edu.au/brain-basics/memory/how-are-memories-formed
- Short term memory, Simply Psychology. Recogido a 30 de octubre en https://www.simplypsychology.org/short-term-memory.html#:~:text=The%20duration%20of%20short%20term,a%20process%20known%20as%20rehearsal.
- Cabarcas, J. M. E., & Alhucema, W. F. P. Memoria de Trabajo: El modelo multicomponente de Baddeley, otros modelos y su rol en la práctica clínica. PRESIDENTA SALA GENERAL, 14.