Ologies with Alie Ward: Mnemonology (MEMORY) Part 1 with Michael Yassa
Release Date: December 4, 2024
Host: Alie Ward
Guest: Dr. Michael Yassa, Neurobiologist and Director of the Center for the Neurobiology of Learning and Memory at UC Irvine
1. Meet Dr. Michael Yassa
Dr. Michael Yassa is a distinguished neurobiologist specializing in the study of memory. With an extensive academic background, including a master's from Johns Hopkins University and a Ph.D. from UC Irvine, Dr. Yassa has dedicated his career to understanding the complexities of how our brains encode, store, and retrieve memories. As the director of UC Irvine's Center for the Neurobiology of Learning and Memory, he oversees groundbreaking research aimed at unraveling the mysteries of memory formation and retention.
2. Understanding Memory: Mnemonology
Alie Ward introduces the concept of mnemonology (preferred term: the study of memory) as the scientific exploration of how memories are formed, stored, and recalled. Contrary to popular belief, mnemonology is not just about enhancing memory but understanding its fundamental mechanisms.
Notable Quote:
“Mnemonology is not a word that this guest really likes because someone else wrote a book using it. He has nothing to do with the book and that person's Google alerts [are] going to get screwed up because of this.”
— Alie Ward [03:24]
3. Debunking Memory Myths
Tip-of-the-Tongue Phenomenon: One common myth about memory is the "tip-of-the-tongue" phenomenon, where individuals feel they know a word or name but cannot immediately recall it. Dr. Yassa explains that this is a normal part of cognitive function, often resulting from distraction and the brain's constant competition for attention.
Notable Quote:
“It happens all the time and largely because we are distracted... It happens all of the time and largely because we are distracted.”
— Alie Ward [08:16]
Myth of Using Only 10% of Our Brain: Another pervasive myth is that humans only utilize 10% of their brain capacity. Dr. Yassa emphatically debunks this, explaining that every part of the brain has a known function and that brain cells require constant activity to remain healthy.
Notable Quote:
“We use all of our brain all the time, and it really depends on what it is that we're doing at any given time.”
— Alie Ward [31:15]
4. Memory Storage in the Brain
The Role of the Hippocampus: The hippocampus, a seahorse-shaped structure in the temporal lobe, is pivotal in converting short-term memories into long-term ones. It acts as an index, connecting various aspects of a memory stored across different brain regions.
Notable Quote:
“The hippocampus is what brings the pieces together into one solid component. We call it an index.”
— Alie Ward [25:25]
Neuroplasticity: Memory storage is distributed throughout the brain, facilitated by neuroplasticity—the brain's ability to reorganize itself by forming new neural connections. This adaptability allows memories to become more robust and resistant to loss over time.
5. Factors Influencing Memory
Neurotransmitters and Hormones: Memory formation and recall are influenced by various neurotransmitters like dopamine and hormones such as estrogen and cortisol. Dopamine not only motivates but also plays a role in how memories are stored, especially those associated with rewards.
Notable Quote:
“Dopamine is what we call a neuromodulator. It is not necessarily the thing that makes memory happen, but it can improve the quality of memory storage.”
— Alie Ward [46:18]
Hormones like estrogen significantly impact memory, particularly in women during different life stages such as menopause. Proper hormonal balance is crucial for maintaining optimal memory function.
Impact of Stress: Stress hormones can both enhance and impair memory. Acute stress can improve memory consolidation, while chronic stress may lead to memory deficits.
Notable Quote:
“Stress is one of those things where some of it is positive, positive. Too much of it is obviously very negative.”
— Alie Ward [49:12]
6. Types of Memories
Episodic vs. Procedural Memory: Memory is not monolithic. Episodic memories pertain to personal experiences and events, while procedural memories involve skills and tasks. These different types of memories engage distinct neural systems within the brain.
Notable Quote:
“Memories for events that happen, people that you meet... that does rely on the hippocampus, at least initially.”
— Alie Ward [22:19]
7. Exceptional Memory: Hyperthymesia
Highly Superior Autobiographical Memory (HSAM): Only about 100 individuals worldwide have been identified with HSAM, allowing them to recall nearly every day of their lives with vivid detail. Dr. Yassa discusses the implications of such an ability and its rarity.
Notable Quote:
“Only about 100 people on Earth have been identified as having highly superior autobiographical memory...”
— Dr. Michael Yassa [33:22]
However, having HSAM can present social challenges, as perfect memory does not necessarily equate to emotional well-being.
8. Reliability of Memories: False Memories and Flashbulb Memories
False Memories: Research has shown that memories, even of traumatic or highly emotional events, are susceptible to distortions over time. Dr. Yassa references studies demonstrating that confidence in memory does not always correlate with accuracy.
Notable Quote:
“Yet when you look at this body of literature... that even though the confidence in those memories is extremely high and the emotional context is extremely high, the actual accuracy of the details sometimes can be quite low.”
— Alie Ward [64:31]
Flashbulb Memories: These are vivid recollections of significant events (e.g., JFK assassination, September 11 attacks). While individuals are highly confident in these memories, their accuracy can be questionable.
Notable Quote:
“These are incredibly detailed kinds of recollections. And no one ever questioned their veracity... the actual accuracy of the details sometimes can be quite low.”
— Dr. Michael Yassa [65:44]
9. Evolutionary Perspective on Memory
Contrary to the notion that memory evolved primarily for reminiscing, Dr. Yassa explains that memory's primary evolutionary function is to inform future decisions for survival. Memory systems are optimized to extract useful information from past experiences rather than to create perfect records.
Notable Quote:
“Memory did not evolve for us to be able to reminisce and tell stories and think about our past history. The only reason it evolved to be what it is today is to allow us to make decisions that are better for us in the future.”
— Alie Ward [53:47]
10. Synesthesia and Memory Enhancement
Synesthesia: Synesthesia, a condition where stimulation of one sensory pathway leads to automatic experiences in another (e.g., seeing colors when hearing music), can influence memory by creating additional sensory connections.
Notable Quote:
“Synesthesia... elicits creativity and it leads to a very interesting experience of the real world around you.”
— Alie Ward [73:57]
Dr. Yassa discusses how synesthesia can be both a boon for creativity and, in extreme cases, can lead to social and cognitive challenges.
11. Memory Across Lifespan and Neurodiversity
Memory and Aging: As individuals age, changes in memory function are influenced by factors like hormonal shifts (e.g., decreased estrogen) and increased cognitive load from modern life’s distractions. However, neurobiological advancements continue to reveal more about these changes.
Memory in Neurodivergent Individuals: Dr. Yassa touches on how memory operates in individuals with neurodivergent conditions, emphasizing that memory systems are diverse and complex.
12. Traumatic Memories and PTSD
Traumatic experiences, such as being held at knifepoint or childbirth, can lead to conditions like Post-Traumatic Stress Disorder (PTSD). These memories can be fragmented, vivid, or distorted, affecting individuals' perception and emotional well-being.
Notable Quote:
“Nearly half of all study participants who gave birth perceived the experience as traumatic... more birthing education before labor and support from medical personnel can lessen the perception and the memory of the trauma.”
— Dr. Michael Yassa [62:50]
13. Plasticity and Sensory Adaptation
The brain's plasticity allows it to adapt to sensory deficits. For instance, individuals born blind may experience cross-sensory activation where visual areas of the brain respond to auditory stimuli, enhancing other senses.
Notable Quote:
“Cortex is cortex throughout. And the same stuff that makes your visual cortex also makes your auditory cortex...”
— Alie Ward [78:10]
14. Concluding Insights
Dr. Yassa and Alie Ward emphasize that while significant strides have been made in understanding memory, much remains to be discovered. Memory is a dynamic, malleable process shaped by various biological, psychological, and social factors. Future research continues to explore the intricate mechanisms behind memory storage, retrieval, and its impact on human behavior and identity.
Final Thought:
“Our memories are constantly being corrupted... your memory system and your brain have extracted whatever knowledge was necessary to be able to promote your survival successfully.”
— Alie Ward [69:08]
Next Episode Preview
In Part 2 of this series, Alie Ward and Dr. Yassa will delve deeper into listener questions, exploring topics such as remembering names and faces, causes of dementia, photographic memories, amnesia, short-term memory, and the interplay between memory and executive function.
Notable Quotes with Timestamps
-
Alie Ward [08:16]:
“It happens all the time and largely because we are distracted... It happens all of the time and largely because we are distracted.” -
Dr. Michael Yassa [25:25]:
“The hippocampus is what brings the pieces together into one solid component. We call it an index.” -
Alie Ward [31:15]:
“We use all of our brain all the time, and it really depends on what it is that we're doing at any given time.” -
Dr. Michael Yassa [33:22]:
“Only about 100 people on Earth have been identified as having highly superior autobiographical memory...” -
Alie Ward [46:18]:
“Dopamine is what we call a neuromodulator. It is not necessarily the thing that makes memory happen, but it can improve the quality of memory storage.” -
Alie Ward [53:47]:
“Memory did not evolve for us to be able to reminisce and tell stories and think about our past history. The only reason it evolved to be what it is today is to allow us to make decisions that are better for us in the future.” -
Alie Ward [64:31]:
“Yet when you look at this body of literature... that even though the confidence in those memories is extremely high and the emotional context is extremely high, the actual accuracy of the details sometimes can be quite low.” -
Dr. Michael Yassa [62:50]:
“Nearly half of all study participants who gave birth perceived the experience as traumatic... more birthing education before labor and support from medical personnel can lessen the perception and the memory of the trauma.”
For more information on Dr. Michael Yassa's research and the UC Irvine Center for the Neurobiology of Learning and Memory, visit UC Irvine's Center.
Stay tuned for Part 2 of this episode, where Dr. Yassa and Alie Ward will answer listener questions and delve deeper into the fascinating world of memory.