Chapter 7 (M33)

Module 33- Forgetting, Memory Construction, & Improving Memory

Henry Molaison (H.M.)

  • Had much of his hippocampus removed to stop seizures —> unable to form new conscious memory

Types of Forgetting

  1. Anterograde Amnesia: an inability to form new memories due to injury or illness

  2. Retrograde Amnesia: an inability to retrieve information from one’s past due to injury or illness

Why do we forget?

  1. Encoding failure

    • What we fail to encode, we will never remember

    • Age can affect encoding efficiency

  2. Storage decay

    • The course of forgetting is initially rapid, then levels off with time

  3. Retrieval failure

    • Often, forgetting is not memories faded but memories unretrieved

    • Sometimes, important events defy attempts to access them

Ebbinghaus’ Forgetting Curve

  • After hearing lists of nonsense syllables, Ebbinghaus studied how much he retained up to 30 days later. He found that memory for novel information fades quickly, then levels out

What are 2 factors that influence memory retrieval errors?

  1. Proactive interference: the forward-acting disruptive effect of older learning on the recall of new information

    • The old stuff you learned is getting in the way of the new stuff you are trying to remember now

  2. Retroactive interference: the backward-acting disruptive effect of newer learning on the recall of old information

    • The new stuff you learned is making it hard to remember the old stuff you learned

Repression and Anxiety-Arousing Thoughts (Sigmund Freud)

  • Freud proposed that forgetting may be due to repression - the basic defense mechanism that banishes from consciousness anxiety-arousing thoughts, feelings, and memory

Reconsolidation

  • Reconsolidation: a process in which previously stored memories, when retrieved, are potentially altered before being stored again

Misinformation Effect

  • Misinformation effect: occurs when misleading info has distorted one’s memory of an event

How does imagination impact memory?

  • Repeatedly imagining nonexistent actions & events can create false memories

  • Imagined events also later seem more familiar, and familiar things seem more real

  • The more vividly we imagine things, the more likely they are to become memories

Source Amnesia

  • Source amnesia: faulty memory for how, when, or where info was learned or imagined

  • Tends to affect a person’s explicit memory & along with the misinfomation effect, is at the heart of many false memories

  • Possible explanation for deja vu