Unit 2.7: Forgetting and Other Memory Challenges

AP Psychology | Unit 2: Cognition

🎯 Exam Focus

Forgetting and memory distortion are critical topics on the AP Psychology exam. Master the forgetting curve, causes of forgetting (encoding failure, storage decay, retrieval failure), interference theory (proactive and retroactive), repression, memory reconstruction errors (misinformation effect, source amnesia, constructive memory), and understand why eyewitness testimony is unreliable. These concepts appear frequently in both multiple-choice and FRQ sections.

📚 Introduction to Forgetting

Forgetting is the inability to retrieve information that was previously encoded and stored in memory. It's a normal, universal experience that happens to everyone.

While forgetting can be frustrating, it's not always a bad thing — it helps our brains filter out irrelevant information and focus on what's important. However, understanding why and how we forget is crucial for improving memory and recognizing memory errors.

Memory is not a perfect recording system. Instead, it's a reconstructive process that's vulnerable to distortion, interference, and decay.

📉 The Forgetting Curve

Ebbinghaus's Forgetting Curve

The forgetting curve, discovered by Hermann Ebbinghaus, shows how memory retention declines over time when information is not actively reviewed or rehearsed.

Key Pattern:

Rapid initial decline: We forget most information very quickly — up to 70% within the first 24 hours
Slowing decline: After the initial steep drop, the rate of forgetting gradually slows down
Leveling off: Eventually, forgetting reaches a plateau where remaining memories become more stable
Retention improves with review: Each time you review material, the curve becomes less steep

Implications for Learning:

The forgetting curve demonstrates why spaced practice (distributed practice) is more effective than cramming (massed practice). Reviewing material at increasing intervals combats the natural decline and strengthens long-term retention.

🔍 Causes of Forgetting

Encoding Failure

Encoding failure occurs when information never enters long-term memory in the first place because it wasn't properly processed or attended to during encoding.

Why It Happens:

Lack of attention: You weren't paying attention to the information
Shallow processing: Only superficial processing occurred (structural or phonemic, not semantic)
Divided attention: Multitasking prevented deep encoding
No elaboration: Information wasn't connected to existing knowledge

Example:

You can't remember what a penny looks like in detail even though you've seen thousands of pennies. This isn't forgetting — you never encoded the specific details in the first place because you didn't pay attention to them.

Storage Decay (Decay Theory)

Decay theory proposes that memory traces physically fade over time if they are not accessed or used. Unused neural pathways weaken and eventually disappear.

Memory traces deteriorate naturally with time
Without rehearsal or retrieval, connections between neurons weaken
The longer the time since encoding, the weaker the memory becomes
Explains the forgetting curve's pattern

Important Note:

Decay alone doesn't fully explain forgetting. Many "forgotten" memories can be retrieved with the right cues, suggesting the information is still stored but inaccessible, not decayed.

Retrieval Failure

Retrieval failure occurs when information is stored in memory but cannot be accessed due to missing retrieval cues or inappropriate retrieval conditions.

Memory is stored but temporarily inaccessible
Lack of appropriate retrieval cues
Mismatch between encoding and retrieval conditions
Demonstrates that storage and retrieval are separate processes

Example - Tip-of-the-Tongue Phenomenon:

You know you know someone's name, can picture their face, and might even know the first letter or how many syllables it has, but you can't quite retrieve it. This is retrieval failure — the memory is there, but you can't access it without the right cue.

⚡ Interference Theory

What is Interference?

Interference theory proposes that we forget because other memories compete with and disrupt the memory we're trying to retrieve. Similar information stored in memory interferes with recall.

The more similar the competing memories, the greater the interference. Interference is especially strong when memories are learned close together in time.

Proactive Interference

Proactive interference occurs when old, previously learned information interferes with your ability to learn or recall new information.

Direction:

Old Memory → Interferes with → New Memory

Examples:

You learned French in high school, and now when you're trying to learn Spanish, French words keep interfering
Your old phone number keeps coming to mind when you try to remember your new one
You keep calling your new teacher by your old teacher's name
Previous knowledge of how to drive a manual car interferes with learning automatic transmission

Retroactive Interference

Retroactive interference occurs when new, recently learned information interferes with your ability to recall old, previously learned information.

Direction:

New Memory → Interferes with → Old Memory

Examples:

After learning Spanish, you can't remember some French words you used to know
Learning your new phone number makes you forget your old one
After moving to a new house, you have trouble remembering your old address
New study material interferes with remembering what you studied earlier in the day

💡 Memory Trick

PROactive = PROblems from the PAST (old interferes with new)
RETROactive = RETRO means going BACK in time (new interferes with old)

🛡️ Motivated Forgetting

Repression (Psychodynamic Theory)

Repression is a psychodynamic defense mechanism where the mind unconsciously pushes disturbing, anxiety-provoking, or traumatic memories out of conscious awareness to protect the ego from psychological harm.

Key Points:

Unconscious process: Happens automatically without awareness
Protects the ego: Shields consciousness from painful memories
Freudian concept: Part of psychoanalytic theory
Controversial: Limited empirical support from modern research
Traumatic memories are often vividly remembered, not repressed

⚠️ AP Exam Note:

You should know repression as a psychodynamic perspective on forgetting, but be aware that most memory scientists prefer cognitive explanations (encoding failure, interference, retrieval failure) that have stronger empirical support.

Suppression

Suppression is the conscious, intentional effort to not think about or remember something — deliberately pushing thoughts out of awareness.

Key Difference: Unlike repression (unconscious), suppression is a conscious, deliberate act of trying to forget.

🔄 Memory Reconstruction and Distortion

Constructive Memory

Constructive memory refers to the idea that memories are not exact recordings but are actively reconstructed each time they're recalled, using stored fragments, schemas, and current knowledge to fill in gaps.

Memory is a reconstruction, not a reproduction
We piece together memories from bits of stored information
Gaps are filled in using schemas and general knowledge
Each retrieval can slightly alter the memory
Explains why memories change over time

Implication:

Because memory is reconstructive, it's vulnerable to errors, distortions, and false details being incorporated without our awareness.

Misinformation Effect (Elizabeth Loftus)

The misinformation effect occurs when exposure to misleading information after an event distorts or alters the memory of that event.

How It Works:

You witness an event and form an initial memory
Later, you're exposed to misleading information (questions, news reports, conversations)
The misleading information gets incorporated into your memory during consolidation or reconstruction
You confidently recall false details as if they were part of the original event

Classic Example - Loftus Car Accident Study:

Participants watched a video of a car accident. Those asked "How fast were the cars going when they smashed into each other?" estimated higher speeds and were more likely to falsely recall seeing broken glass than those asked about cars that "hit" each other. The word "smashed" created a misleading expectation that distorted memory.

Source Amnesia (Source Misattribution)

Source amnesia occurs when you remember information or a fact but cannot remember where, when, or how you learned it — you've forgotten the source of the memory.

Characteristics:

Content of memory is retained, but context is lost
Can lead to misattributing memories to wrong sources
Often works with misinformation effect
Contributes to false memories and confabulation

Examples:

You remember a fact but can't recall whether you read it in a book, heard it from a friend, or saw it online
You think you came up with an idea yourself when you actually heard it from someone else
An eyewitness remembers details from a crime but confuses what they actually saw with what they heard in news reports

Imagination Inflation

Imagination inflation is the tendency for vividly imagining an event to increase confidence that the event actually occurred, even if it didn't.

Repeatedly imagining an event creates a memory trace
The imagined event feels increasingly familiar
Eventually, you may believe the imagined event really happened
Demonstrates how imagination can become confused with reality

Example:

Participants who repeatedly imagined performing childhood actions (like breaking a window) became more confident they had actually done these things, even though they hadn't.

👁️ Eyewitness Testimony Reliability

Why Eyewitness Testimony is Unreliable

Eyewitness testimony is often compelling in court, but research shows it's surprisingly unreliable and subject to numerous errors and distortions.

Factors that Compromise Eyewitness Accuracy:

Misinformation effect: Leading questions and post-event information alter memories
Source amnesia: Witnesses confuse what they saw with what they heard later
Encoding failure: High stress and attention to weapons reduce peripheral detail encoding
Interference: Multiple events or interviews create confusion
Constructive memory: Gaps are filled in with expectations and schemas
Time: Memory decays and distorts over time (forgetting curve)
Confidence ≠ Accuracy: Eyewitnesses can be very confident but completely wrong

⚠️ Important Implication:

Many wrongful convictions have been based on confident but inaccurate eyewitness testimony. DNA evidence has exonerated numerous people who were identified by eyewitnesses, demonstrating the serious limitations of human memory in legal contexts.

🧠 Types of Amnesia

Retrograde Amnesia

Loss of memories formed before the injury or trauma

Direction:

Cannot recall the PAST

Example: After a head injury, you can't remember events from the past year

Anterograde Amnesia

Inability to form new long-term memories after the injury

Direction:

Cannot remember the FUTURE (new events)

Example: Patient H.M. — could remember his childhood but couldn't form new memories

📚 Using Forgetting Research to Study Better

Combat the Forgetting Curve

Use spaced practice: Review material at increasing intervals (1 day, 3 days, 1 week, 2 weeks) to combat decay
Employ retrieval practice: Test yourself frequently instead of just re-reading (testing effect)
Encode deeply: Use elaborative rehearsal, semantic processing, and meaningful connections to prevent encoding failure
Reduce interference: Study similar subjects at different times; sleep between study sessions
Use multiple retrieval cues: Study in varied contexts and create multiple associations
Overlearn material: Continue studying even after you can recall it once
Get sleep: Sleep after studying helps consolidation and prevents retroactive interference

📝 AP Exam Strategy

Multiple Choice Tips

Know the forgetting curve: Rapid initial decline, then gradual leveling off
Distinguish causes of forgetting: Encoding failure (never stored), decay (fades over time), retrieval failure (can't access)
Master interference: Proactive (old → new) vs. Retroactive (new → old)
Understand memory distortion: Misinformation effect, source amnesia, constructive memory, imagination inflation
Know amnesia types: Retrograde (can't recall past) vs. Anterograde (can't form new memories)
Recognize repression: Psychodynamic perspective with limited empirical support
Understand eyewitness unreliability: Why testimony is vulnerable to errors

Free Response Question (FRQ) Tips

Provide concrete examples: For each forgetting concept, give specific, clear real-world scenarios
Explain mechanisms: Why does proactive interference occur? How does the misinformation effect distort memory?
Apply to scenarios: Show how interference would affect a student learning two languages
Compare and contrast: Proactive vs. retroactive interference; encoding failure vs. retrieval failure
Connect to Loftus research: Use her car accident study to explain misinformation effect
Link concepts: How do constructive memory, source amnesia, and misinformation effect work together?
Use precise terminology: Say "retroactive interference" not "new memories blocking old ones"

✨ Quick Review Summary

🔑 The Big Picture

Forgetting occurs due to multiple causes. The forgetting curve (Ebbinghaus) shows rapid initial memory loss that gradually levels off. Encoding failure means information never entered long-term memory. Decay theory proposes memories fade over time without use. Retrieval failure occurs when stored memories can't be accessed (tip-of-the-tongue). Interference theory shows how memories compete: proactive interference (old blocks new) and retroactive interference (new blocks old). Repression (psychodynamic) is unconscious blocking of traumatic memories (limited support). Memory is reconstructive, not reproductive, leading to distortions. Misinformation effect (Loftus) shows how post-event information alters memories. Source amnesia means forgetting where information came from. Imagination inflation makes imagined events feel real. Constructive memory fills gaps with schemas. These factors make eyewitness testimony unreliable. Amnesia: retrograde (can't recall past) vs. anterograde (can't form new memories).

💡 Essential Concepts

Forgetting
Forgetting curve (Ebbinghaus)
Encoding failure
Storage decay
Decay theory
Retrieval failure
Tip-of-the-tongue phenomenon
Interference theory
Proactive interference
Retroactive interference
Repression
Suppression
Motivated forgetting
Constructive memory
Misinformation effect
Source amnesia
Imagination inflation
Eyewitness testimony
Retrograde amnesia
Anterograde amnesia
Elizabeth Loftus

📚 AP Psychology Unit 2.7 Study Notes | Forgetting and Other Memory Challenges

Master forgetting theories and memory errors for exam success!