STM Functions

Functions of Short-Term Memory Explained

Researchers have observed that Short-term memory (STM) is like having a mental computer screen that stores a limited amount of information that is automatically erased after a brief period of time and replaced by new information, on and on and on, and so the cycle continues.

Short-term memory is also called working memory to indicate that it’s an active process. It typically functons as follows:

1. Attending

Imagine driving along with your radio on while a friend in the passenger seat is talking about the weekend. A tremendous amount of information is entering your sensory memory Opens in new window, but you avoid stimulus overload because incoming information automatically vanishes in seconds unless you pay attention to it.

The moment you pay attention to information in sensory memory, that information enters short-term memory Opens in new window for further processing. For example, while your friend is talking, you don’t pay attention to the radio until your favorite song comes on and enters sensory memory. As you pay attention, you hear the radio, even though it has been playing the whole time. One function of short-term memory is that it allows us to selectively attend to information that is relevant and disregard everything else.

2. Rehearsing

Once information enters short-term memory, it usually remains for only seconds unless you rehearse Opens in new window it. For example, the announcer on the car radio gives a phone number to call for free movie tickets. But unless you rehearse or repeat the number over and over, it will probably disappear from short-term memory because of interference Opens in new window from newly arriving information. Another function of short-term memory is that it allows you to hold information for a short period of time until you decide what to do with it.

If you rehearse the information in short-term memory, you increase the chances of storing it.

3. Storing

Rehearsing information not only holds that information in short-term memory but also helps to store or encode information in long-term memory.

Using brain scans, researchers found that short-term memory involves the front part of the brain, especially the prefrontal area (Pessoa & Ungerleider, 2004).