Notes on Memory: Recency, Encoding, and Desirable Difficulty

Memory and Encoding: A Deeper Dive

The Recency Effect and Temporal Distinctiveness

  • Recency Effect: Refers to better memory for recently encountered items.

  • Temporal Distinctiveness Account: This theory explains the recency effect based on the distinctiveness of items in time.

    • Ratio Rule: A key component of the temporal distinctiveness account. It states that a recency effect is not expected if the retention interval (the time between initial exposure to an item and the memory test) exceeds the spacing interval (the time between different events or items during encoding).

      • Example (Class Schedule): If a lecture occurred a week ago, and classes normally meet with irregular, shorter intervals (e.g., every 22 days, then 55 days, then 22 days, then 55 days, followed by a 77-day break), you would not expect a recency effect for the last lecture. The 77-day retention interval is greater than the typical spacing intervals of 22 or 55 days.

      • Counter-example: If the class met only every week, or every two weeks (making the spacing interval longer), then a 11-week break would be less than or equal to the typical spacing interval, and a recency effect would be expected for the last lecture. Similarly, if there was a short interval (e.g., a Zoom call on Saturday), a recency effect would be observed.

Improving Memory: Focus on Encoding

  • Exam Improvement: A significant portion of improving memory performance, especially for exams, hinges on what happens during the encoding phase.

  • Encoding: The process of taking in an event or stimulus and processing it. How one thinks about and focuses on information during this phase significantly impacts memory.

Revisiting Past Concepts and Important Information

  • Working Memory Training (N-back Test): A previous lecture discussed whether N-back training could improve fluid IQ (the ability to process and adapt to new information).

    • Replication Crisis: Initial promising findings were likely a Type I error (a false positive in statistics) as subsequent efforts have failed to replicate the original results.

  • Physical Training and Cognition: A crucial video from Art Kramer (University of Illinois) highlights