Short-term memory (STM) is often likened to a mental workspace where information is temporarily held and manipulated. Typically, STM holds information for about 20-30 seconds, after which it either gets lost or is encoded into long-term memory if it's deemed important enough.
For example, consider that you're dialing a phone number someone has just told you. You hold the number in your short-term memory long enough to complete the task. If you don't rehearse the number or find it significant, it will fade away shortly.
STM is essential for a range of cognitive tasks:
- Problem-solving: allows you to hold and process information simultaneously.
- Learning: involves interacting new information with existing knowledge.
- Decision-making: helps you evaluate options and make choices.
The capacity of short-term memory is limited and is often thought to be around 7±2 items, as proposed by psychologist George A. Miller. This limitation highlights why chunking, or grouping items into larger clusters, can enhance memory.