Understand & Improve Memory Using Science-​​Based Tools

Memory and Context

• Memory is not just about learning, but also about placing life events into context
• The human brain can place events in the context of past, present, and future events
• Memory is about how immediate experiences relate to previous and future experiences

Memory Formation

• Sensory stimuli (touch, light, smell, taste, sound) are converted into electrical and chemical signals by the nervous system
• The nervous system’s primary job is to convert physical events into electrical and chemical signals, which are the language of the nervous system
• We only perceive a small amount of sensory information, allowing us to make sense of the world around us without being overwhelmed

Memory Bias

• Memory is a bias in which perceptions will be replayed again in the future
• Memory is a bias in the likelihood that specific chains of neurons (neural circuits) will be activated again
• For example, remembering your name involves specific chains of neurons in your brain that represent your name

Tools for Enhancing Memory

• Over 100 studies in animals and humans point to specific protocols for enhancing learning and memory
• These tools can also be used to forget or unload the emotional weight of unwanted experiences
• Topics like deja vu and photographic memory will be discussed
• Protocols grounded in peer-​​reviewed research can help improve encoding and remembering specific events

Memory Formation and Types of Memory

Ebbinghaus and Learning Curves

• Ebbinghaus developed learning curves in the late 1800s, early 1900s
• Learning curves quantify how many repetitions are required to remember something
• Ebbinghaus demonstrated that repetition activates particular sequences of neurons, laying down a memory

Donald Hebb’s Postulate

• Hebb’s postulate: if a sequence of neurons is active at the same time or roughly the same time, it leads to a strengthening of the connections between those neurons
• Most of the time, learning occurs because existing neurons strengthen their connections through co-​​activation, not because new neurons are added

One-​​Trial Learning

• One-​​trial learning: experiencing something once and remembering it forever
• Can be associated with both positive and negative events
• Strong activation of neurons can lay down memory traces

Types of Memory

• Short-​​term memory
• Medium-​​term memory

• Long-​​term memory
  Types of Memory

• Short-​​term memory 
  • Working memory: ability to keep information in mind for a short period of time 
    • Example: remembering a phone number or security code
• Long-​​term memory 
  • Ability to commit information or motor patterns to memory for long periods of time 
    • Can remember information days, weeks, months, or even years later

Categories of Memory

• Explicit memory
  • Declarative memory: knowing something and being able to declare it 
    • Example: knowing your name or the color of your partner’s hair
  • Procedural memory: knowing how to perform an action sequence 
    • Example: knowing how to walk or ride a bike
• Implicit memory
  • Subconscious understanding of information or motor patterns 
    • Example: walking without thinking about how to walk

Brain Structures Involved in Memory

• Hippocampus
  • Establishes explicit declarative memories
  • Not where memories are stored and maintained
• Cerebellum and neocortex 
  • Form and store implicit memories

Case Study: HM

• HM had intractable epilepsy with severe grand mal seizures
• Focus of seizures was the hippocampus
• Neurosurgeon removed the hippocampus to control seizures
• HM lost all explicit memory, but retained some memories from before the surgery 
  • Suggests memories are not stored in the hippocampus, but formed there
    HM Case Study and Memory

• HM: a patient with epilepsy who underwent neurosurgery

• Lost explicit declarative memory but retained implicit knowledge 
  • Could perform tasks like walking, making coffee, and recognizing people from his past
• Emotionality and residual capacity to learn new information 
  • Example: HM could still find jokes funny, but with each repetition, he found them less funny 
    • Suggests humor is related to procedural memory rather than explicit content

Emotions and Memory Enhancement

• Emotions can enhance memories, even for non-​​emotional information
• Neurochemicals in the brain and body play a role in this enhancement
• Repetition strengthens nerve connections, but can be time-consuming

Experiments on Emotion and Memory

• James McGaugh and Larry Cahill conducted experiments on humans 
  • Subjects read either a mundane paragraph or an emotionally intense paragraph
  • Those who read the emotionally intense paragraph remembered more content and were more accurate
• Francis Bacon (1620): “Memory is assisted by anything that makes an impression on a powerful passion inspiring fear, for example, or wonder, shame or joy.”

Stress and Memory Enhancement

• McGaugh and Cahill evaluated the capacity for stress and neurochemicals associated with stress to improve learning and memory 
  • Animal experiments: Rats and mice learned to avoid locations where they received an electrical shock (one-​​trial learning)
  • This effect is hippocampal-​​dependent learning
    One Trial Learning and Emotional States
• Animals can learn from one trial if the experience is emotionally intense 
  • Condition place avoidance: avoiding a location where something negative happened
  • Condition place preference: returning to a location where something positive happened
• Both positive and negative one trial learning depend on the release of adrenaline 
  • Not just about stress, but heightened emotional states

Adrenaline and Memory

• Adrenaline (epinephrine) and cortisol play a role in memory formation 
  • Adrenaline released in the body and brain, cortisol released from adrenal glands
  • Adrenaline has local effects, cortisol has longer-​​term effects and can permeate the brain and body
• Emotional state after experiencing something dictates whether it will be learned quickly or not

Blocking Emotional State and Adrenaline

• Experiments by McGaugh and Cahill showed that blocking adrenaline response with beta blockers prevented memory enhancement 
  • High emotional states help learning, but it’s the neurochemical state (adrenaline, norepinephrine, cortisol) that allows memory to be stamped down quickly

Applying Knowledge for Enhanced Learning

• To optimize learning, consider the timing of the release of adrenaline and other neurochemicals 
  • Traditional approach: hydrate and caffeinate before learning
  • Enhanced protocol: engage in activities that evoke adrenaline release after experiencing something to strengthen neural connections and improve memory

Conclusion

• Understanding the role of adrenaline and other neurochemicals in memory formation can help us develop better strategies for learning and retaining information. By engaging in activities that evoke adrenaline release after experiencing something, we can strengthen neural connections and improve memory without the need for repetition.
  Caffeine and Learning

• Caffeine creates a sense of alertness in the brain and body 
  • Blocks the effects of adenosine, reducing feelings of fatigue
  • Increases alertness by increasing epinephrine (adrenaline) release
  • Increases the efficacy of dopamine receptors
• Traditionally, caffeine is consumed before or during learning sessions 
  • However, research suggests that it might be more beneficial to consume caffeine late in the learning session or immediately after

Optimal Timing for Adrenaline Release

• Studies show that triggering the release of adrenaline late in learning or immediately after learning is most beneficial for retaining information 
  • Reduces the number of repetitions required to learn
• This is contrary to the belief that naps or deep sleep should be taken immediately after learning 
  • Sleep and naps are still important for learning and memory, but can be done hours later

Spiking Adrenaline Safely

• Pharmacological substances like caffeine or Alpha GPC can be used to spike adrenaline, but only if done safely and with a doctor’s approval
• Non-​​pharmacological methods, such as immersing one’s arm in an ice bath, can also be used to evoke adrenaline release 
  • This method is low-​​cost and does not require external substances
    Enhancing Learning and Memory with Adrenaline

• Spike adrenaline after learning to improve memory retention

• Adrenaline can be increased through pharmacology or behavioral protocols

Pharmacological Approaches

• Caffeine
• Alpha GPC
• ADHD medications (Ritalin, Adderall, Modafinil) — only if prescribed by a physician

Behavioral Protocols

• Cold exposure (cold shower, ice bath) 
  • Should be uncomfortably cold to evoke adrenaline release
  • Can be adjusted according to individual tolerance
• Physical exercise (running, high-​​intensity workouts)

Timing of Adrenaline Spike

• Best time to spike adrenaline is late in the learning process or immediately after
• Spiking adrenaline before learning can increase alertness but is less effective for memory enhancement
• Chronic elevation of adrenaline can be detrimental to learning and immune system function
• Acute, sharp increases in adrenaline can enhance learning and immune system function

Historical Use of Adrenaline for Memory Enhancement

• In medieval times, communities threw young children in the river after witnessing important events to create a lifelong memory

• This practice unknowingly utilized the adrenaline spike to enhance memory retention
  Medieval Adrenaline and Memory Enhancement

• Medieval practice of spiking adrenaline to enhance learning and memory 
  • Robust emotional experience after an event would encourage the child’s nervous system to remember
  • Cold water induced adrenaline used to enhance learning and memory since Medieval times

Neural Mechanisms of Memory

• Amygdala: brain structure associated with threat detection and emotional states 
  • Detects correlations between sensory events and emotional states
  • Interconnected with other areas of the brain, can strengthen connections easily
  • Emotional saliency and increases in epinephrine and cortisol are conditions for memory formation
  • Amygdala is a correlation detector, not a thinking area

Exercise and Memory Enhancement

• Exercise has been shown to enhance learning and memory in numerous studies
• Cardiovascular exercise increases Dentate Gyrus neurogenesis (creation of new neurons) 
  • Dentate Gyrus is a subregion of the hippocampus involved in memory formation and consolidation
  • New neurons are important for the formation of certain types of new memories
• 180–200 minutes per week of zone two cardiovascular exercise (steady state) can enhance memory 
  • Improvements in cardiovascular function indirectly impact the ability of the Dentate Gyrus to create new neurons
  • Enhancements in blood flow and lymphatic flow are related to improvements in neurogenesis
• Exercise can also impact learning and memory through hormones from bones 
  • Hormones from bones travel in the bloodstream to the brain and enhance hippocampus function
  • Bones make hormones, which can have endocrine effects on the body
    Osteocalcin and Exercise for Brain Health
• Osteocalcin: a chemical released from bones that acts as a hormone 
  • Released during load-​​bearing exercise
  • Travels to the brain and improves hippocampal function and memory
  • Also involved in bone growth and hormone regulation
• Eric Kendell’s lab at Columbia Medical School studies the effects of exercise on hippocampal function and memory 
  • Cardiovascular exercise releases osteocalcin, which enhances hippocampal function
• The brain and body are closely connected, with much of the brain’s “real estate” dedicated to movement 
  • The release of osteocalcin during exercise signals to the brain that the body is moving and helps maintain neural circuitry
• Best time to exercise for brain health: 
  • Exercise that spikes adrenaline should be done after a learning session
  • Exercise that enhances blood flow and osteocalcin release should be done 1–3 hours before a learning session

Photographic Memory and Super Recognizers

• Photographic memory: the ability to visually scan and commit a page of text to memory with little effort 
  • People with photographic memory may struggle with auditory memory and learning physical skills
• Super recognizers: individuals with an exceptional ability to recognize faces and match them to templates 
  • Highly employable by government agencies
    Super Recognizers and the Fusiform Gyrus
• Super recognizers have an incredible ability to recognize faces and template match 
  • Useful for jobs in agencies where facial recognition is important
• Fusiform gyrus: area of the brain responsible for face recognition and template matching 
  • Responds to faces and their emotional content
• Face blindness: some people struggle to recognize faces, even of people they know well

The Value of Visual Images for Memory

• Study: “Photographic Memory: The Effects of Volitional Photo-​​taking on Memory for Visual and Auditory Aspects of an Experience” 
  • Explores the use of camera photographs and mental photographs for memory enhancement
• Mental snapshots: looking at something and “snapping” a mental image of it 
  • Can create strong visual memories

Taking Photos and Memory Enhancement

• Study found that when people choose what to take photos of, their memory for those objects, places, or people is enhanced 
  • Applies to both camera photos and mental snapshots
• Taking photos can degrade the ability to remember auditory information
• Keeping or deleting photos had no bearing on memory enhancement 
  • The act of taking the photo itself is what enhances memory

Mental Snapshots and Memory Enhancement

• Taking mental snapshots can enhance visual memory significantly 
  • Almost as effective as taking an actual photograph with a camera

• Useful for learning visual information and creating detailed understanding of a scene
  Deja Vu and Memory Encoding

• Deja vu: a sense of familiarity with a situation, place, or person that cannot be explained

• Sasumu Tonagawa (MIT) and Mark Mayford (Scripps Institute, UC San Diego) studied deja vu
• They evaluated neural firing patterns in the hippocampus during learning 
  • Neuron A fires, then neuron B, then neuron C, creating a sequence
  • This sequence is like playing keys on a piano, creating a memory
• They used molecular tools to activate neurons in the same or different sequence 
  • Found that different patterns of firing can evoke the same memory or behavior
• Deja vu may be a result of the hippocampus encoding experiences in different sequences

Meditation for Learning and Memory

• Study by Wendy Suzuki (New York University)
• Title: “Brief daily meditation enhances attention, memory, mood, and emotional regulation in non-​​experienced meditators”
• Subjects aged 18–45, not experienced in meditation
• Two groups: one did a 13-​​minute daily meditation, the other listened to a podcast
• After eight weeks, meditation group showed significant improvements in attention, memory, mood, and emotional regulation
• However, meditation late in the day impaired sleep quality 
  • Meditation increases attention and prefrontal cortical activity, which may inhibit sleep

Takeaways

• 13 minutes of daily meditation can enhance attention, learning, and memory
• Must practice for at least eight weeks to see effects

• Be cautious of meditating late in the day, as it may impair sleep quality
  Meditation and Cognitive Abilities

• 4 weeks of meditation not enough to show effects

• 8 weeks of meditation for 13 minutes a day can improve cognitive abilities and learning
• Author plans to increase meditation to 15 minutes a day
• Best to do meditation sessions early in the day to avoid inhibiting sleep

Memory and Emotional Saliency

• Emotional intensity during learning impacts memory formation
• Epinephrine and cortisol play a role in enhancing memory
• Adjusting the timing of these chemicals is key to enhancing memory

Exercise and Memory

• Load-​​bearing exercise can release hormones like osteocalcin
• Osteocalcin travels from bones to the brain, enhancing learning

Photographic Memory

• Taking mental snapshots can create better memory of visual information
• However, it may reduce memory for auditory information

Meditation Protocols and Memory

• Certain meditation protocols can enhance memory, attention, and mood
• If done too late in the day, they can disrupt sleep due to enhanced attention

Neurochemicals and Memory

• Adrenaline is the final common pathway for memory formation
• Increasing adrenaline can be done through behavioral protocols or pharmacology
• Epinephrine is a key factor in determining which events are remembered