5 Differences Between Short-term Memory and Working Memory

Memory is a fundamental cognitive function that allows us to process, store, and retrieve information. Two critical types of memory involved in daily cognitive tasks are short-term memory (STM) and working memory (WM). While they are often used interchangeably, they serve distinct purposes in cognitive psychology and neuroscience. Below, we explore the five key differences between these two memory systems.

What is memory?

The memory refers to a cognitive process, which involves the ability to record and recall memories. That is, it allows the registration of external (and internal) information to later store said information, making it available to evoke it at another time. However, there are many types of memories, depending on the criteria we use to classify them.

The part of psychology that is responsible for studying memory is basic psychology, which also studies other psychological and cognitive processes such as learning, perception, sensation, motivation, and reasoning.

Origin of short-term memory and working memory

At a historical level, the first classification made of memory was the one that divided this mental capacity into: short-term memory and long-term memory. While the first referred to the memory of events that just occurred a few seconds ago (i.e., the ability to store and recall said events in the mind), the second referred to the ability to remember long-term, i.e. , events that have occurred longer ago.

This first classification of memory was proposed by Atkinson and Shiffrin in 1968. In this first classification, short-term memory was understood as a rather “static” process, that is, it simply referred to the fact of remembering or not remembering recent information (that we had recorded a few seconds before).

Later, however, another author suggests a slightly different definition of short-term memory. This author was Alan Baddeley, and he recommended the concept of working memory or working memory within the central executive model. According to him, short-term memory is a type of working memory, understood as a type of “active”, “dynamic” memory, which is not only limited to evoking information, but actively transforms it to use it in tasks required.

For example, working memory It is what we use when we are adding, subtracting, multiplying or dividing high figures, and that allows us to manipulate and “memorize” the numbers that we are using to reach a final result. That is, what A. Baddeley did was add executive functioning to short-term memory.

Differences between short-term memory and working memory

Authors other than A. Baddeley, however, consider that short-term memory and working memory consist of two totally different and independent concepts. Knowing all this, let’s summarize the differences between short-term memory and working memory:

1. Definition and Function

• Short-Term Memory (STM): Refers to the ability to hold a small amount of information for a brief period (usually 15–30 seconds) without actively manipulating it. STM serves as a temporary storage system for immediate recall, such as remembering a phone number before dialing it.

• Working Memory (WM): Is a more complex system that not only stores information temporarily but also actively processes and manipulates it. WM is essential for tasks like mental arithmetic, problem-solving, and language comprehension.

Example

• STM: Remembering a string of numbers (e.g., 476281) for a few seconds.

• WM: Performing a mental calculation using those numbers (e.g., 476 + 281).

2. Capacity Differences

• Short-Term Memory: Has a limited capacity, typically holding 5 to 9 items (Miller’s “Magic Number 7 ± 2” theory). This means we can only retain a small set of information before it either decays or is replaced.

• Working Memory: Also has a limited capacity, but it can expand when used efficiently. Working memory divides resources into different components, allowing multitasking and complex cognitive operations.

Example

• STM might allow you to remember a short grocery list (bread, milk, eggs).

• WM enables you to rearrange the list mentally to match the order of the store aisles.

3. Active Processing vs. Passive Storage

• Short-Term Memory: Acts as a passive storage system, holding information without modification. If not rehearsed or transferred to long-term memory, the information fades quickly.

• Working Memory: Involves active processing. It not only stores information temporarily but also organizes, modifies, and integrates it with long-term knowledge to complete tasks.

Example

• STM: Listening to a friend’s address and keeping it in mind for a moment.

• WM: Writing down the address while remembering how to spell the street name.

4. Neural Basis and Brain Regions

• Short-Term Memory: Primarily involves the hippocampus and parts of the prefrontal cortex. These areas briefly store information before it is either discarded or transferred to long-term memory.

• Working Memory: Relies more on the prefrontal cortex, parietal lobes, and cingulate cortex. These regions allow for attention control, information manipulation, and problem-solving.

Example

• STM: A patient with hippocampal damage may struggle to hold new information momentarily.

• WM: A person with prefrontal cortex damage might find it hard to plan and organize thoughts.

5. Role in Cognitive Tasks

• Short-Term Memory: Plays a role in basic recall tasks, such as recognizing words, numbers, or objects over a short duration.

• Working Memory: Is crucial for complex cognitive tasks, including decision-making, reasoning, and multitasking.

Example

• STM: Watching a movie and remembering the last spoken line before a scene change.

• WM: Following a complicated movie plot, keeping track of different characters and their relationships.

Table: Key Differences Between Short-Term Memory and Working Memory