Forgetting Curves Slides Cognitive Forensics
Forgetting and Interference
Why do memories vanish or transform?
Memory Lab
The Memory Challenge
List A: Memorize these!
ZOK
BAP
VIB
LUM
TEG
RIJ
Why are these hard to remember? Hermann Ebbinghaus used these Nonsense Syllables to study pure memory without associations.
"We forget the most rapidly right after learning." — Hermann Ebbinghaus
The Forgetting Curve
100% Retention Time Elapsed
Key Takeaways:
Forgetting is exponential .
Loss is rapid in the first 20 minutes.
Retention levels off after 24 hours.
Overlearning and Spacing can flatten the curve.
Interference Theory
Proactive
Old information hinders the recall of new information.
Example: You keep calling your new puppy by your old dog's name.
Retroactive
New information hinders the recall of old information.
Example: You learn a new password and can no longer remember your old one.
Is forgetting a bug or a feature?
Imagine if you remembered every single license plate, receipt, and meaningless conversation from the last 10 years.
How would that impact your ability to function?
Interference Simulation Worksheet Interference Lab
Topic: Proactive & Retroactive Interference
Investigator Name
Date
The Objective
In this simulation, you will test how learning new information can interfere with old information (Retroactive) and how old information can block new learning (Proactive). Follow your teacher's instructions to memorize the lists provided in the timed intervals.
Phase 1: Raw Data Collection
Trial A: Control
Memorize List 1. Test Recall after 2 minutes.
Score:
/ 10
Trial B: Interference
Memorize List 1. Immediately memorize List 2. Test Recall of List 1.
Score:
/ 10
Critical Analysis
1. Based on your scores, which Trial was more difficult? Why do you think the introduction of List 2 affected your ability to remember List 1?
2. Identify the type of interference: If your memory of List 2 was impaired because you kept thinking of List 1, what type of interference occurred?
Proactive
Retroactive
3. Real-World Application: You move to a new house and get a new street address. Six months later, you can't remember your old address. Is this proactive or retroactive interference? Explain.
Simulation Materials: Syllable Lists
LIST 1
BEP
ZOT
KIB
VAM
GUR
NOL
WEX
JAF
YIM
LUP
LIST 2
MOV
DAK
REL
SHI
TUP
FON
KEZ
BIV
YOT
WUL
Forgetting Teacher Guide Teacher Facilitation Guide
Lesson 1: Forgetting & Interference
Est. Duration 55 Minutes
Learning Objectives
Analyze the Ebbinghaus Forgetting Curve to understand the rate of decay in short-term memory.
Distinguish between proactive and retroactive interference through empirical simulation.
Evaluate the role of interference as a retrieval failure versus a storage failure.
Key Vocabulary
Decay Theory Retrieval Failure Overlearning Nonsense Syllables
Pacing & Facilitation
10m Hook/Intro
The Memory Challenge
Display List A from the slides for 30 seconds. Ask students to write down as many as they recall. Use this to introduce Ebbinghaus and the concept of "pure memory" without semantics.
20m Activity
Interference Simulation
Distribute the Interference Simulation Worksheet . Conduct the two trials as a class. For Trial B, ensure students memorize List 2 immediately after List 1 to maximize interference.
Teacher Tip:
Encourage students to be honest with their data. The goal is to see a drop in performance, not to "win" the memory test.
15m Lecture
Direct Instruction
Review the Forgetting Curve and the specific definitions of Proactive and Retroactive interference. Use the puppy/password examples to solidify understanding.
10m Debrief
Closing Discussion
Discuss the "bug or feature" question. Connect forgetting to cognitive efficiency—why we need to prune irrelevant information.
Common Misconceptions
Proactive vs. Retroactive
Students often confuse these. Teach the PORO acronym: P roactive = O ld interferes with new; R etroactive = N ew (O ff) interferes with old.
Forgetting as Erasure
Students think forgetting means the memory is deleted. Emphasize that in interference, the memory often still exists but the access path is blocked.
Schema Theory Slides Cognitive Forensics
The Constructive Mind
Schemas, Stereotypes, and Memory Rebuilding
The 30-Second Glance
In a classic experiment (Brewer & Treyens, 1981), students sat in an office for 30 seconds.
The Result:
"I remember seeing books on the shelves."
— BUT THERE WERE NO BOOKS.
Why did they "see" books?
Their Schema for an office includes books. Their brain "filled in the blanks" to make the memory consistent with their expectations.
The Mental Blueprint: Schemas
Organization
Mental frameworks that help us organize and interpret vast amounts of info.
Shortcuts
They allow us to take cognitive shortcuts when processing new situations.
Construction
They provide the "mortar" used to rebuild memories from fragmented bits of data.
How Memories Transform
Leveling
Memory becomes shorter; details that don't "fit" the schema are dropped.
Sharpening
Specific details that do fit the schema are highlighted or exaggerated.
Assimilation
Details are changed to better fit the person's own cultural background or expectations.
War of the Ghosts
Frederic Bartlett (1932) wanted to know: What happens when you tell a story from a different culture to a group of British students?
Prepare for the simulation.
War of the Ghosts Activity War of the Ghosts
Serial Reproduction Activity
Subject No.
Part 1: Initial Encoding
Read the following Native American folk tale carefully. You will have 2 minutes. Focus on the details of the events.
One night two young men from Egulac went down to the river to hunt seals and while they were there it became foggy and calm. Then they heard war-cries, and they thought: "Maybe this is a war-party." They escaped to the shore, and hid behind a log. Now canoes came up, and they heard the noise of paddles, and saw one canoe coming up to them.
There were five men in the canoe, and they said: "What do you think? We wish to take you along. We are going up the river to make war on the people." One of the young men said: "I have no arrows." "Arrows are in the canoe," they said. "I will not go along. I might be killed. My relatives do not know where I have gone. But you," he said, turning to the other, "may go with them." So one of the young men went, but the other returned home.
And the warriors went on up the river to a town on the other side of Kalama. The people came down to the water and they began to fight, and many were killed. But presently the young man heard one of the warriors say, "Quick, let us go home: that Indian has been hit." Now he thought: "Oh, they are ghosts." He did not feel sick, but they said he had been hit. So the canoes went back to Egulac and the young man went ashore to his house and made a fire. And he told everybody and said: "Behold I accompanied the ghosts, and we went to fight. Many of our fellows were killed, and many of those who attacked us were killed. They said I was hit, and I did not feel sick." He told it all, and then he became quiet. When the sun rose he fell down. Something black came out of his mouth. His face became contorted. The people jumped up and cried. He was dead.
Part 2: Reconstruction
After your teacher gives the signal, write down everything you remember about the story below. Be as accurate as possible.
Part 3: Comparative Analysis
1. LEVELING: What details did you forget or leave out? Why do you think those specific details were lost?
2. SHARPENING: Did you emphasize or exaggerate any part of the story (e.g., the "something black")?
3. ASSIMILATION: Did you change any "unfamiliar" details to fit your own cultural expectations? (e.g., changing "canoes" to "boats", or "seals" to "fish")?
Schema Investigation Key Teacher Resource Key
Lesson 2: Schema & Reconstruction
Analysis Focus Qualitative Data
1. Bartlett's Findings
Bartlett found that memory is reconstructive , not reproductive. Students will likely transform the story to fit their Western, 20th/21st-century "Schema." Look for these specific shifts in their writing:
2. Discussion Prompts
"Why did we all forget the name of the towns (Egulac, Kalama)?"
"How many of you changed 'seals' to 'fish'?"
"Did anyone add a 'moral' to the story that wasn't there?"
What to look for in Student Work
Assimilation (Transformation)
Changing details to fit existing cultural frameworks.
Examples: "Canoe" → "Boat"; "Hunting seals" → "Fishing"; "Something black came out of his mouth" → "He coughed up blood" or "He was foaming at the mouth."
Leveling (Omission)
Shortening the story by dropping unfamiliar or "irrelevant" details.
Examples: Forgetting the names of the locations; forgetting the specific number of men (5); omitting the conversation about why the relative shouldn't go.
Sharpening (Exaggeration)
Adding details or intensifying emotions/events to make the story more "logical."
Examples: Emphasizing the "ghost" element as a horror story; adding more violence to the battle; creating a clearer cause-and-death relationship.
Sociocultural Connection
The "War of the Ghosts" experiment is an excellent bridge to discussing Stereotypes as Schemas .
"Schemas aren't just for stories. We have schemas for people. When a person doesn't fit our schema, do we 'level' their unique traits or 'assimilate' them into our preconceived stereotypes?"
"How might this impact a witness describing a suspect from a different racial or cultural background?" (Preview for Lesson 4).
Misinformation Effect Slides Cognitive Forensics
Implanted Memories
The Misinformation Effect & Loftus's Legacy
Memory Vulnerability
How fast were they going?
Loftus & Palmer (1974) showed participants a video of a car crash. They asked the same question, but changed one word :
"About how fast were the cars going when they ______ each other?"
"Smashed" 40.5 MPH
"Hit" 34.0 MPH
"Contacted" 31.8 MPH
The Persistence of Error
One week later...
"Did you see any broken glass?"
"Smashed" group: 32% said YES
"Hit" group: 14% said YES
Fact: There was NO broken glass in the video.
The Misinformation Effect
Incorporating misleading information into one's memory of an event.
The leading question didn't just change their estimate—it changed their mental image of the event.
The DRM Paradigm
List A
BED
REST
AWAKE
TIRED
DREAM
SNORE
NAP
PEACE
Most people will later swear they saw the word SLEEP on the list.
This is a False Memory —a mental representation of an event that never occurred.
"Memory is more like a Wikipedia page—you can go in and change it, but so can other people."
— Elizabeth Loftus
Loftus Investigation Lab Investigation Lab 03
Topic: The Misinformation Effect & DRM Paradigm
Lead Investigator
Lab Date
Phase 1: The Semantic Associate Task (DRM)
Your teacher will read a list of words. Do not write them down yet. Listen carefully. Once the list is finished, you will have 60 seconds to write down as many as you can remember.
Recall Area (Write the words you remember here):
Self-Check:
I recalled the word "SLEEP" (or the target word).
BUT "SLEEP" WAS NOT ON THE LIST.
Phase 2: Analyzing the "Smashed" Study
1. Why did the word "smashed" cause participants to estimate a higher speed than the word "hit"? Link this to the concept of schemas.
2. The "Misinformation Effect" suggests that the question itself becomes part of the memory. How does this challenge the idea of memory being a "video recording" of the past?
Phase 3: Forensic Application
The Scenario: A witness is being interviewed by a detective. The detective asks: "Did you see the blue car speed through the stop sign?"
In reality, the car was green and there was no stop sign .
Identify two potential "False Memories" this question might create in the witness's mind:
Memory 1...
Memory 2...
False Memory Discussion Guide False Memory Discussion Guide
Lesson 3: Loftus & Misinformation
Focus Area Research Ethics
DRM List Facilitation
Read these lists at a steady pace (1 word per 2 seconds). Do not emphasize the themes. After the students finish their recall, ask: "How many of you had [Critical Lure] on your list?"
List 1 (Theme: Sleep)
Bed, Rest, Awake, Tired, Dream, Wake, Snooze, Blanket, Doze, Slumber, Snore, Nap, Peace, Yawn, Drowsy
Critical Lure: SLEEP
List 2 (Theme: Needle)
Thread, Pin, Eye, Sewing, Sharp, Point, Prick, Thimble, Haystack, Thorn, Hurt, Injection, Syringe, Cloth, Knitting
Critical Lure: NEEDLE
Ethical Socratic Seminar
Question 1: The Right to Forget
Elizabeth Loftus has been a consultant on many high-profile criminal cases, often casting doubt on victim testimony. Is it ethical for a scientist to use their research to potentially discredit someone's memory of a traumatic event?
Question 2: Implanting Positives
Loftus also conducted a study where she convinced participants they once liked asparagus as a child (when they didn't), leading them to eat more asparagus later. If we can use false memories to promote healthy habits (dieting, exercise, quitting smoking), should we? Or is any manipulation of memory inherently wrong?
Connecting to Legal Systems
The "Misinformation Effect" isn't just a classroom trick. It highlights why Suspect Interviews must be carefully controlled.
"Once a witness 'remembers' the blue car because of a leading question, they are not lying. They genuinely believe they saw it. This makes their testimony incredibly convincing to a jury, even though it's false."
Justice and Memory Slides Legal Module 04
Justice and Memory
When the Witness is Wrong
Case Study Analysis
Write Your Report
An intruder just ran through this room. You have 3 minutes to write a full physical description.
Key Details Needed:
Height/Weight?
Clothing color/logos?
Facial hair or glasses?
Was he/she carrying anything?
"I'd never forget that face."
Most witnesses are 100% confident and 100% wrong . Confidence does NOT equal accuracy.
A Failure of Identification
In 1984, Jennifer Thompson was sexually assaulted. She studied her attacker's face so she would never forget him.
She picked Ronald Cotton from a photo lineup and a physical lineup. He spent 11 years in prison.
DNA evidence later proved Bobby Poole was the real attacker. Jennifer had falsely identified Ronald.
Why did it happen?
1
Relative Judgment: She picked the person who looked most like the attacker, even if the real attacker wasn't there.
2
Reinforcement: When she picked him, the detective said "Good job." This solidified her false memory.
Weapon Focus
When a weapon is present, a witness's attention is narrowed .
They can describe the gun in vivid detail but cannot remember the attacker's face.
"The brain prioritizes survival over identification."
How do we fix the system?
Sequential Lineups
Show photos one at a time. No "comparing" faces allowed.
Double-Blind
The officer showing the photos shouldn't know who the suspect is.
Ronald Cotton Case Study Case Analysis 04-RC
The State vs. Ronald Cotton
Student Analyst
Review Date
The Context
In July 1984, an assailant broke into Jennifer Thompson's apartment. During the attack, Jennifer made a conscious effort to memorize every detail of the man's face. Days later, she identified Ronald Cotton from a photo array. Later, she identified him again in a physical lineup. Cotton was convicted and sentenced to life plus 54 years. He maintained his innocence throughout. In 1995, DNA testing revealed that the real perpetrator was Bobby Poole, a man Thompson had seen but not identified in court.
Evidence Type
Eyewitness Identification
Status Wrongful Conviction
Psychological Post-Mortem
1. The Commitment Effect
Once Jennifer identified Cotton in the photo array, her memory of the actual attacker was replaced by the photo of Cotton. This is called the "Commitment Effect." How does this relate to the Misinformation Effect we studied in Lesson 3?
2. Reinforcement and Confidence
When Jennifer made her identification, detectives told her, "You did a great job." Psychologically, how does this feedback "sharpen" (Bartlett's term) a false memory and increase witness confidence?
Policy Recommendation
Imagine you are a consultant for the local police department. Based on what you know about the fallibility of memory, propose two specific changes to how they should conduct witness lineups to prevent what happened to Ronald Cotton.
Reform #1
Reform #2
Eyewitness Reliability Rubric Assessment Rubric
Case Analysis: Memory & Justice
Max Score 20 Points
Criteria Exemplary (5) Proficient (3-4) Developing (1-2) Psychological Integration Clearly connects Ronald Cotton's case to 2+ psychological terms (e.g., schemas, interference). Mentions psychological terms but links are somewhat superficial. Does not use psychological terminology; focuses only on the narrative. Synthesis of Lessons Explains how photo arrays function as "misinformation" via the Commitment Effect. Identifies the error but lacks specific connection to "misinformation" concepts. Understands the error but cannot explain why it happened psychologically. Evidence-Based Reform Proposes 2 specific, evidence-backed reforms (e.g., sequential, double-blind). Proposes 2 reforms, but they are vague or not fully explained. Proposes 1 or no reforms; lacks psychological justification. Critical Thinking Analyzes the relationship between detective feedback and witness confidence. Notes that confidence increased but doesn't explain the mechanism. Does not address the role of confidence or reinforcement.
Instructor Feedback Area
Strengths:
Areas for Growth:
Final Score:
/ 20
Source Amnesia Slides Cognitive Forensics
Who Told Me That?
Source Amnesia & Cognitive Biases
Lesson 05: Synthesis
The "Familiar" Stranger
Have you ever told a "vivid story" from your childhood, only to have your parent tell you it happened to your brother?
Source Amnesia
Attributing to the wrong source an event we have experienced, heard about, read about, or imagined.
How it works:
We remember the information (the gist), but we lose the tag for where it came from. This is the root of many false memories.
"I Knew It All Along"
Hindsight Bias
The tendency to believe, after learning an outcome, that one would have foreseen it.
"I knew that team would lose!"
"It was obvious she was guilty!"
Why it's a memory issue:
Learning new information distorts your memory of what you originally believed. Your brain "overwrites" your past uncertainty.
Availability Heuristic
The Rule:
If it's easy to remember, it must be common/important.
The Flaw:
Vivid, emotional, or recent memories (like a plane crash) come to mind easier than statistics (car crashes).
"We fear what is vivid in memory, not what is statistically dangerous."
The User's Manual for Memory
You have explored why we forget, how we rebuild, and how we are misled.
Your final task: Create a guide for humans to help them navigate the fallibility of their own minds.
Memory User Manual Project Synthesis Project
Memory: A User's Manual
Lead Author
Deadline
The Challenge
You have spent the last four lessons learning that human memory is not a hard drive, but a living, breathing, and often buggy reconstruction. Your final task is to design a "User's Manual" for the human memory system. This manual should explain how the system works and, more importantly, how to avoid common "system errors."
Core Requirements
1. Maintenance Guide (Lesson 1)
How do we prevent "data loss"?
Explain Proactive/Retroactive Interference .
Offer one evidence-based tip to prevent forgetting (e.g., Spacing Effect).
2. System Vulnerabilities (Lessons 2 & 3)
Why does the system "fill in the blanks"?
Define Schemas and how they lead to "Construction Errors."
Explain the Misinformation Effect —how external data (questions) can corrupt the file.
3. Troubleshooting & Verification (Lessons 4 & 5)
How do we know if a memory is "real"?
Explain Source Amnesia —why we forget where a "memory" came from.
Provide a warning about Hindsight Bias ("I knew it all along").
Choose Your Medium
Print Brochure
A physical fold-out guide.
Digital Deck
A "System Support" slide presentation.
Audio Script
An automated "Help Desk" recording.
Memory Synthesis Assessment Final Synthesis Guide
Unit Culmination: Memory Reliability
Project Type Summative Mastery
Mastery Rubric (50 Points)
Criteria Mastery (90-100%) Progressing (70-89%) Technical Accuracy Correctly defines and applies all 6+ key concepts: Interference, Schemas, Misinformation Effect, False Memory, Source Amnesia, and Hindsight Bias. Defines most concepts correctly but makes minor errors in application (e.g., confuses proactive/retroactive). Evidence-Based Advice Offers concrete, practical strategies for mitigating memory errors based on Lesson 1-4 research (e.g., sequential lineups, spacing). Advice is generic (e.g., "try harder to remember") rather than psychologically informed. Creative Synthesis The "User Manual" metaphor is sustained throughout; content is accessible and engaging for a non-psychologist audience. Manual feels like a standard worksheet or essay; metaphor is weak or inconsistent.
"Look-Fors" in Final Projects
Maintenance: Mention of Spacing or Overlearning to combat the Forgetting Curve.Vulnerabilities: Mention that leading questions "corrupt" the "file."Verification: Warning that "high confidence" does not mean a "high-quality file."
Unit Reflection
By the end of this project, students should move from seeing memory as a Fixed Tool to a Dynamic Process .
"The best students will recognize the metacognitive benefit: knowing that your memory is fallible makes you a better critical thinker and a more humble observer of reality."
Post-Project Seminar Topic
"Now that you know your memory isn't always reliable, how does this change the way you view history books, family stories, or even your own eyewitness accounts?"
