Medicine & USMLE

Short-Term Memory

  1. Sensory Memory
  2. Short-Term Memory
  3. Working Memory
  4. Long Term Memory


Short-term memory is the type of memory responsible for holding, but not manipulating, a small amount of information. Short-term memory holds around 7 pieces of information, and it lasts for about 30 seconds.

Key Points

  • Short Term Memory (STM)
    • Second step of information processing model
      • Occurs after Sensory Memory, but before Long Term Memory
      • Thought to operate in parallel with Working Memory on different tasks
    • Function
      • For holding but not manipulating information
        • Manipulation of information is domain of Working Memory
    • Duration
      • 20-30 seconds (short-term)
    • Capacity
      • 7 +/- 2 pieces of information
      • Derived from Miller, G. A. (1956). "The magical number seven, plus or minus two: Some limits on our capacity for processing information". Psychological Review. 63 (2): 81–97.