Forgetting & Eyewitness Memory

Early Forgetting Research (Ebbinghaus, 1884)

Hermann Ebbinghaus

• First person to study memory scientifically

• Used himself as participant (memorizing nonsense syllables)

👉 Goal: measure pure forgetting

The Classic Forgetting Curve 🔥

• Memory drops very fast at first

• Then levels off over time

👉 Key idea:

• Most forgetting happens soon after learning

Decay Hypothesis

Memory fades because:

• it is not used over time

BUT ❗

• This alone cannot explain all forgetting (interference matters more)

Interference Theory (VERY IMPORTANT)

Forgetting happens because memories compete.

Proactive Interference

Old info blocks new info

Example:

• Old password makes it hard to remember new one

Retroactive Interference

New info blocks old info

Example:

• New locker combo makes you forget old one

Role of Similarity (Skaggs-Robinson Law

The more similar two memories are:

• the more they interfere with each other

Brown–Peterson Paradigm 🔥

• Participants see a word + number

• Must count backwards

• Then recall word

👉 Result:

• Memory drops quickly without rehearsal

✔ Shows:

• STM forgets fast without rehearsal

• Interference causes forgetting

Eyewitness Memory (VERY TESTED)

Problem:

Memory is reconstructive, not recorded

Misinformation Effect

After an event, new misleading info changes memory

Example:

• “How fast did the car smash?” vs “hit?”
  → changes recall

False Memory Syndrome / False Episodic Memories

People can remember events that NEVER happened

• Memory feels real but is incorrect

The Innocence Project (REAL WORLD APPLICATION

• Organization that uses DNA evidence

• Shows many wrongful convictions due to:

  • faulty eyewitness memory

  • false identifications

👉 Big takeaway:
❗ Memory is NOT perfectly reliable

Mousetrap Study

What happened:

• Many children began to “remember” details that never actually happened

• Even when they had not seen those events, they sometimes:

  • confidently said they remembered them

  • or incorporated the suggested details into their memory

  • 💡 What it shows:

    👉 Children’s memories are highly suggestible
    👉 They can form false memories when given leading questions or suggestions
    👉 Memory is not just a “recording”—it can be reconstructed

Memory Systems (IMPORTANT DISTINCTION) 🔸 Procedural Memory

• Skills (bike riding)

• “how to do

Memory Systems - Semantic Memory

Facts (Paris is France)

Memory Systems- Episodic Memory

Personal experiences (your birthday)

Memory Systems - Autobiographical Memory

Combination of episodic + personal meaning

Semantic Network & Spreading Activation (link to LTM)

• Concepts are connected in memory

• Activating one spreads to others

👉 Explains:

• priming effects

• retrieval speed differences

Indirect Memory Tasks (VERY IMPORTANT)

Test memory without asking directly

4 common indirect tasks:

1. Word stem completion

   • “DOC___” → doctor

2. Word fragment completion

   • “d c t r” → doctor

3. Perceptual identification

   • identifying degraded images/words

4. Priming tasks

   • faster responses after exposure

👉 These measure implicit memory