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Short-Term Memory Overview

Jun 29, 2025

Overview

This lecture covers the properties and limitations of short-term memory, including its duration, capacity, interference, and strategies to improve memory retention such as chunking and the use of acronyms.

Short-Term Memory: Basics & Limitations

  • Short-term memory (STM) holds information briefly while it is being actively used.
  • STM is limited in duration (how long info is retained) and space (amount of info held at once).
  • Interference from competing stimuli negatively affects STM performance.

Experiments & Effects

  • Memory tests examine STM duration (time given to recall) and capacity (amount to remember).
  • Longer delays before recall and increased distractors both reduce memory performance.
  • Memory decay occurs when information is not rehearsed, as shown by Ebbinghaus's research.
  • Ebbinghaus identified the "retention curve," showing rapid information loss soon after learning.

Serial Position Effect: Primacy & Recency

  • People recall first (primacy effect) and last (recency effect) items in a list best.
  • Middle items are most likely to be forgotten due to limited rehearsal time and interference.
  • Real-life examples: Remembering names, lecture content, and lists.

Capacity & Chunking

  • Typical STM capacity is 7 (±2) items.
  • Chunking (grouping items into meaningful units) increases effective memory capacity.
  • Chunking can involve creating words, dates, or acronyms from information.

Acronyms, Anagrams, and Associations

  • Acronyms (e.g., HOMES for the Great Lakes) help condense and remember multiple items.
  • Anagrams combine information for easier recall.
  • Creating personal associations (linking names with features) also aids memory retention.

Key Terms & Definitions

  • Short-Term Memory (STM) — A memory system for holding information temporarily while it is used.
  • Interference — Distraction or competing information that hampers memory retention.
  • Decay (Ebbinghaus) — The fading of memory over time when not rehearsed.
  • Primacy Effect — Tendency to remember the first items in a sequence best.
  • Recency Effect — Tendency to remember the most recent or last items best.
  • Chunking — Grouping separate pieces of information into larger, meaningful units.
  • Acronym — A word formed from the first letters of a series of items.
  • Anagram — A rearrangement of letters or data into meaningful words or phrases.

Action Items / Next Steps

  • Practice chunking, creating acronyms, and making associations when studying new material.
  • Prepare for the next lecture on long-term memory.