Section 8.3: Problems with Memory Study Notes - Amnesia, Memory Errors, and Interference

Amnesia: Types and Case Studies

• Definition of Amnesia: Amnesia is the loss of long-term memory caused by disease, physical trauma, or psychological trauma. This condition causes the inability to recall information stored in long-term memory or the inability to create new memories.

• Case Study: K. C.: Endel Tulving ($2002$) and colleagues at the University of Toronto studied K. C. for years after he suffered a traumatic head injury in a motorcycle accident. The outstanding fact about his mental state was his utter inability to remember any events, circumstances, or situations from his own life. This episodic amnesia covered his entire life from birth to the present, except for experiences occurring within the last minute or two ($1 - 2\,minutes$).

• Anterograde Amnesia:

  • Description: This form of amnesia prevents an individual from remembering new information, although they can recall information and events that occurred prior to the injury.

  • Physical Basis: It is commonly caused by brain trauma, such as a blow to the head, and usually affects the hippocampus. Damage results in the inability to transfer information from short-term to long-term memory (memory consolidation).

  • Example: H. M.: H. M. suffered from anterograde amnesia following surgery. He would read the same magazine repeatedly as it was always new to him. He could not remember people he met; if an acquaintance left the room for a few minutes ($min$), he would not recognize them upon their return.

  • Episodic vs. Procedural Memory: While H. M. could not form new episodic or semantic memories, he could form new procedural memories. For example, when presented with the same puzzle several days in a row, he did not remember seeing it before, yet his speed at solving it became faster each day due to relearning.

• Retrograde Amnesia:

  • Description: This involves the loss of memory for events that occurred prior to the trauma. Sufferers have difficulty recalling their past, particularly episodic memories.

  • Case Study: Scott Bolzan: A former NFL player who fell and hit his head, resulting in one of the most extreme cases of retrograde amnesia on record. Bolzan "deleted" $46\,years$ of his life in an instant and did not recognize his spouse, children, or parents upon waking in the hospital.

  • In Popular Culture: Hollywood has used original amnesia plots since the film Garden of Lies ($1915$) and in modern films like the Jason Bourne spy thrillers.

Memory Construction and Reconstruction

• Construction: The formulation of new memories.

• Reconstruction: The process of bringing up and retrieving old memories from long-term storage.

• Flexibility of Memory: As memories are pulled from long-term storage into short-term memory, they are flexible. New events can be added, and perceptions of past events can change, leading to inaccuracies and distortions. People may not intend to distort facts, but it happens when retrieving old memories and combining them with new ones.

Suggestibility and Eyewitness Misidentification

• Definition of Suggestibility: This describes the effects of misinformation from external sources that lead to the creation of false memories.

• The DC Sniper Case ($2002$):

  • A sniper shot victims at gas stations and Home Depots over a three-week ($3\text{-week}$) period, killing $10\,people$.

  • Law enforcement received over $140,000\,tips$, resulting in approximately $35,000\,suspects$.

  • Following a news report about a white van spotted at a scene, witnesses began reporting white vans almost exclusively, ignoring other details. There were more than $70,000\,white\,vans$ in the area.

  • When late caught, the suspects were actually driving a blue sedan. The "white van" memory was a product of the power of suggestion from news media.

• Eyewitness Misidentification: The Innocence Project has discovered that eyewitness misidentification is a leading cause of wrongful convictions, as evidenced by DNA exoneration cases.

• Case Study: Jennifer Thompson and Ronald Cotton ($1984$):

  • Jennifer Thompson, a $22\text{-year-old}$ student, was raped at knifepoint and tried to memorize the rapist's face.

  • During a photo lineup, she spent $4 - 5\,minutes$ before picking Ronald Cotton, stating, "I think this is the guy."

  • Under reinforcing questioning by detectives ("You're sure? Positive?"), her confidence grew. She later viewed a physical lineup and identified Cotton again, stating he "looks most like him."

  • By the trial, she had no doubt. Cotton was sentenced to life plus $50\,years$.

  • After $4\,years$, a second trial occurred where Cotton was given two ($2$) life sentences.

  • After $11\,years$, DNA evidence proved Cotton's innocence. The real rapist was another man.

• Factors Leading to Misidentification: Suggestive police procedures (stacking lineups, telling witnesses who to identify, or confirming choices with phrases like "Good choice") can turn a hesitant "I think" into false certainty.

• Contrast: The Elizabeth Smart Case:

  • Elizabeth was kidnapped at knifepoint at age $14$. Her $9\text{-year-old}$ sister, Mary Katherine, was the sole witness.

  • Police deliberately avoided showing Mary Katherine lineups or pushing for a composite sketch to avoid implanting false memories or corrupting her fragile memory.

  • Four ($4$) months later, Mary Katherine recalled the abductor's voice (a former handyman), leading to his capture and Elizabeth's return after $9\,months$.

The Misinformation Effect and Memory Research

• Elizabeth Loftus: A cognitive psychologist who developed the misinformation effect paradigm, which states that exposure to additional and possibly inaccurate information after an event can cause a person to misremember the original event.

• Loftus and Palmer Study ($1974$):

  • $45\,U.S.\,college\,students$ watched films of car accidents and were asked to estimate speeds.

  • The verb used in the question influenced the speed estimate:

    • "Smashed": Resulted in the highest speed estimates.

    • "Contacted": Resulted in the lowest speed estimates.

  • One week ($1\,week$) later, participants were asked if they saw broken glass. Those who heard the word "smashed" were more than twice ($2\times$) as likely to falsely remember glass than those in other groups.

• False Memory Syndrome: The recall of false autobiographical memories, often regarding events with no independent witnesses (such as childhood sexual abuse).

• The Repressed Memory Debate:

  • Side A (Sigmund Freud/Briere & Conte): Argues that traumatic memories can be locked away (repressed) for decades to allow a normal life and can be recovered later via hypnosis or guided imagery. A study by Briere and Conte ($1993$) found that $59\%$ of $450\,men\,and\,women$ receiving treatment for abuse that occurred before age $18$ had forgotten their experiences.

  • Side B (Elizabeth Loftus): Skeptical of recovered memories. Loftus argues that therapeutic techniques like hypnosis and age regression can suggest and create false memories.

  • Ceci and Brucks ($1993, 1995$): Found that $55\%$ of $3\text{-year-old}$ children would point to genital/anal areas on an anatomically correct doll to describe a pediatric exam, even if no such exam occurred, based on suggestive questioning.

Forgetting and Encoding Failure

• Definition of Forgetting: Loss of information from long-term memory.

• Encoding Failure: Occurs when memory loss happens before the actual memory process begins because the information was never stored in the first place.

• Effortful Encoding: Actively paying attention to details to process information.

• The Penny/Nickel Example: Nickerson and Adams ($1979$) found most Americans cannot identify the correct details of a U.S. penny or nickel ($Nickel\,Choice\,C$ is correct). This is because we only encode enough detail to distinguish the coin from others, not the redundant specifics.

Schacter’s Seven Sins of Memory

Psychologist Daniel Schacter ($2001$) categorized memory failures into three groups: Forgetting, Distortion, and Intrusion.

Forgetting Errors

• Transience: Accessibility of memory decreases over time (storage decay).

  • Example: Nathan’s mother remembers the character Scout in To Kill a Mockingbird but has forgotten the rest of the plot after years of disuse.

• Absentmindedness: Forgetting caused by lapses in attention or focus being elsewhere.

  • Example (Cynthia): A psychologist confused during a stressful day (daughter sick with the flu) cannot remember if she returned her court ID card, despite having done so $10\,minutes$ prior.

• Blocking: The "Tip of the tongue" (TOT) phenomenon where information is stored but temporarily inaccessible.

  • Example: Being able to picture Morgan Freeman's face and voice but being unable to retrieve his name.

Distortion Errors

• Misattribution: Confusing the source of information.

  • Example (Alejandra/Lucia): Alejandra remembers seeing a movie with Lucia when she actually saw it with someone else.

  • Example (Donald Thomson): A rape victim identified expert Donald Thomson as her attacker because she was watching him on live TV during the assault; she confused his face with the rapist's.

• Suggestibility: False memories that result from leading questions or external influence (e.g., from a therapist or police).

• Bias: Memories distorted by a person's current belief system.

  • Stereotypical Bias: Racial or gender biases (e.g., associating names like Jamal with basketball and Greg with politics).

  • Egocentric Bias: Enhancing our memories of the past to make ourselves look better (e.g., remembering scoring the goal instead of just an assist).

  • Hindsight Bias: The "I knew it all along" phenomenon where an outcome seems inevitable after it has occurred.

Intrusion Errors

• Persistence: The inability to forget undesirable, often traumatic memories that interfere with concentration.

  • Example: A witness to a horrific car accident or a veteran recalling unpleasant war memories.

Storage Decay and the Ebbinghaus Forgetting Curve

• Hermann Ebbinghaus ($1885$): Analyzed memorization using lists of nonsense syllables. He measured retention over periods from $20\,minutes$ to $30\,days$.

• The Forgetting Curve: Shows that memory for new information decays quickly and then levels out.

• Statistics of Decay:

  • An average person loses $50\%$ of memorized information after $20\,minutes$.

  • An average person loses $70\%$ of information after $24\,hours$.

Interference: Proactive and Retroactive

• Proactive Interference: This occurs when old information hinders the recall of newly learned information.

  • Example: Accidentally writing the previous year when a new year starts, or giving an old phone number after getting a new one.

• Retroactive Interference: This occurs when information learned more recently hinders the recall of older information.

  • Example: Studying Ebbinghaus's forgetting curve this week, then studying Erikson's psychosocial theory next week, and subsequently being unable to remember Ebbinghaus's work.