🧠

Memory Forgetting Theories

Aug 27, 2025

Overview

The lecture explores why we forget information from long-term memory, focusing on interference as a key explanation beyond simple memory decay over time.

Decay Theory of Forgetting

  • Hermann Ebbinghaus proposed Decay Theory, which states that memories fade simply due to the passage of time.
  • This theory alone does not fully explain why we forget.

Interference Theory

  • Interference occurs when two memories compete or become mixed up, leading to forgetting.
  • The more similar the information, the greater the interference between memories.
  • Proactive interference: old (past) memories interfere with new learning.
  • Retroactive interference: new memories interfere with the recall of old information.
  • Example: Forgetting where you parked due to previous parking habits is proactive interference.

Research on Interference

  • McGeoch and McDonald (1931) found that learning similar lists (e.g., synonyms) causes more forgetting due to retroactive interference.
  • Artificial tasks in laboratory studies may limit how these findings apply to real-life memory situations.
  • Baddeley and Hitch studied rugby players and found that number of games played (not just passage of time) predicted forgetting, supporting real-world interference effects.

Limitations and the Role of Cues

  • Interference requires memories to be similar, which is not always common in real life.
  • Tolving and Psotka (1971) showed that providing cues restores forgotten memories, indicating interference may cause temporary inaccessibility rather than permanent forgetting.

Key Terms & Definitions

  • Decay Theory — the idea that memory fades over time due to lack of use.
  • Interference — forgetting caused by memories competing or mixing with each other.
  • Proactive Interference — past memories disrupt new learning.
  • Retroactive Interference — new learning disrupts the recall of old memories.
  • Cued Recall — using hints or categories to aid memory retrieval.

Action Items / Next Steps

  • Practice identifying examples of proactive and retroactive interference.
  • Watch the suggested video on retrieval failure and the importance of cues for effective studying.