Lecture Notes: Memory and Its Mechanisms

Iconic Moments and Memories

• Key historical moments often stay etched in memory:
  • Armstrong’s moon landing quote: “That’s one small step for man…”
  • Reagan’s Berlin Wall speech: “Tear down this wall”
  • Death of Princess Diana
  • 9/11 attacks: personal testimonies of witnessing the events

Fallibility of Memory

• Personal memories of significant events can be unreliable
• Around 50% of details in a memory change within a year
• People retain the gist but not specific details
• Example: A woman misremembered details about her mother’s location and the visibility of 9/11 smoke

Mechanics of Remembering

• Memory is fundamental to our interactions with the world
• Only gain attention when it fails

Memory Athletes

• Yanjaa Wintersoul, a grandmaster of memory
• Competitions involving memorizing large sequences rapidly
• Techniques used:
  • Memory palaces
  • Associating numbers with sounds and visual images

Henry Molaison Case Study

• Brain surgery for epilepsy resulted in severe memory loss
• Retained implicit (procedural) and semantic (fact-based) memories
• Loss of episodic memory (personal experiences)
• Important structures: Medial temporal lobe and hippocampus

Stages of Memory Storage

• Multiple sensory inputs from an experience
• Medial temporal lobe combines elements to relive memories
• Life story graph: More recent memories retained better; bump during teens and twenties

Enhancing Memory

• Factors enhancing memory:
  • Emotional experiences
  • Sense of place (location-based memories)
  • Narrative structure
• Techniques proving effective:
  • Healthier lifestyle
  • Meditation for improved focus and memory

Neuroplasticity and Learning

• Henry Molaison’s brain studies
• London cabbies - “The Knowledge” test and hippocampal growth
• Rat studies showing place cell activation

Memory Distortion

• Emotional intensity can distort peripheral details
• Eyewitness testimonies often flawed and influence by repeated exposure
• False memories can be implanted through suggestion and leading questions
  • Example: 70% of subjects accepted false memory of committing a crime

Applications and Misapplications

• Implications for justice system: Unreliable eyewitness testimony
• Research on decay and distortion of personal memories over time

Memory’s Purpose Beyond Recording the Past

• Henry Molaison’s inability to imagine the future
• Brain network linking past and future (Time machine concept)
• Simulation of future events for troubleshooting and planning
• Creating a sense of self by weaving past and future memories