Boost Attention & Memory with Science-Based Tools | Dr. Wendy Suzuki
Summary
Dr. Wendy Suzuki, neuroscientist and NYU professor, shares research-backed insights on how the brain forms and retains memories, and how simple daily behaviors — especially exercise and meditation — can meaningfully improve memory, attention, and long-term cognitive health. The conversation covers the neuroscience of the hippocampus, the two biochemical pathways linking exercise to brain growth, and practical protocols for optimizing brain function at any age.
Key Takeaways
- Four factors make things memorable: novelty, repetition, association, and emotional resonance.
- The hippocampus is critical not just for memory, but for imagination and associating information across past, present, and future.
- Every bout of aerobic exercise releases a “bubble bath” of neurochemicals — dopamine, serotonin, noradrenaline, and BDNF — that directly support hippocampal growth and function.
- A single 30–45 minute aerobic session improves mood, prefrontal attention, and memory performance for at least two hours afterward.
- Two to three cardio sessions per week (45 minutes each) in previously low-fit adults produces measurable improvements in hippocampal memory and attention after just three months.
- For mid-fit people, more exercise correlates with better outcomes — every additional session per week improved mood and hippocampal memory.
- 7–8 hours of sleep dramatically improves willingness to tackle difficult cognitive tasks and overall brain performance.
- Morning exercise is optimal for most people — it aligns the cortisol spike with the early part of the day and primes the brain before demanding cognitive work.
- 10 minutes of walking is enough to produce measurable mood improvements from neurochemical release.
- Fitness levels in midlife (40s) predict up to 9 extra years of good cognition in later life, based on a 40-year longitudinal study of Swedish women.
Detailed Notes
How Memory Works: The Four Pillars
Dr. Suzuki identifies four conditions that make experiences memorable:
- Novelty — New experiences capture attention, and attention is a prerequisite for encoding.
- Repetition — Repeated exposure strengthens memory traces over time.
- Association — Linking new information to existing knowledge (people, places, concepts) makes it easier to encode and retrieve.
- Emotional resonance — Emotionally charged experiences, especially threatening or surprising ones, are encoded more strongly.
The amygdala detects emotionally significant events and amplifies activity in the hippocampus, leading to stronger long-term memory formation. This is why negative or fear-based events (e.g., a break-in, a near-accident) can be encoded in a single exposure — a phenomenon called one-trial learning.
The Hippocampus: Beyond Memory Storage
- The word hippocampus means “seahorse” — named for its curved, seahorse-like anatomical shape.
- The famous patient H.M., who had both hippocampi surgically removed in 1954, lost the ability to form any new long-term memories for facts or events.
- His case established the hippocampus as essential for declarative memory (facts and events).
- Modern view: The hippocampus is not just a memory encoder — it is the brain’s association engine, linking elements of experience across time. It is also required for imagination and mentally simulating future events.
- Long-term memories are ultimately stored in the neocortex, but the hippocampus serves as an intermediate storage area, possibly for years.
- Adult neurogenesis (new neuron growth) in the hippocampus has been confirmed in humans into the ninth decade of life using modern techniques.
Exercise and Brain Function: Two Biochemical Pathways
Dr. Suzuki describes two identified pathways by which physical movement signals the brain to release BDNF (brain-derived neurotrophic factor):
Pathway 1 — Muscle-derived myokine:
- Aerobic exercise causes striated muscles to release a myokine (a signaling protein).
- This myokine crosses the blood-brain barrier and stimulates BDNF release in the hippocampus.
Pathway 2 — Liver-derived beta-hydroxybutyrate:
- Exercise triggers cortisol release (a stress response), which prompts the liver to produce beta-hydroxybutyrate, a ketone body.
- This ketone crosses the blood-brain barrier and independently stimulates BDNF production.
- Note: This ketone is produced during exercise regardless of dietary carbohydrate intake — no ketogenic diet is required.
Result: BDNF acts as a growth factor that promotes the formation of new neurons in the hippocampus (“neurogenesis”) and supports synaptic plasticity.
Acute Effects of a Single Exercise Session
A single 30–45 minute aerobic session consistently produces:
- Improved mood (decreased anxiety, depression, and hostility)
- Improved prefrontal function — measured via the Stroop task and Eriksen flanker task (tests of focused and shifting attention)
- Improved reaction time
- Increased energy
- These effects last at least two hours post-exercise (based on published lab data)
- Older adults (up to 90s) showed equal or greater cognitive improvements compared to younger adults in unpublished pandemic-era research
Chronic Exercise Effects: Protocols from Research
Study 1 — Low-fit adults (ages 30–55):
- Baseline: less than 30 minutes of exercise per week
- Intervention: 2–3 spin classes per week for 3 months (45 min sessions, ~35 min of work)
- Control: competitive video Scrabble (2–3x/week, same group setting)
- Results:
- Improved baseline positive mood
- More positive body image
- Increased motivation to exercise
- Improved performance on Stroop task (prefrontal attention)
- Improved recognition memory and spatial episodic memory (hippocampal tasks)
Study 2 — Mid-fit adults (exercising 2–3x/week at baseline):
- Intervention: Free access to spin studio for 3 months; participants could exercise up to 7x/week
- Control: Maintained existing exercise levels
- Results: A dose-response relationship emerged — every additional session per week produced incrementally better mood and hippocampal memory performance
Key clinical takeaway: You don’t need to be a marathon runner. Two to three cardio sessions per week produces real cognitive benefits in people who are currently sedentary or low-fit.
Dr. Suzuki’s Personal Morning Protocol
She practices this seven days a week:
- 45-minute tea meditation — mindful brewing and drinking of tea (learned from a Taiwanese monk)
- 30-minute cardio + weights workout (via the Daily Burn app — varied formats including kickboxing)
- Hot-cold contrast shower — warm shower followed by a cold blast at the end
- 7.5–8 hours of sleep — extended by one hour after self-experiments during the pandemic revealed she was chronically undersleeping
She notes that the cold shower triggers adrenaline and norepinephrine (from the locus coeruleus), and research shows dopamine increases up to 2.5x baseline and sustains for 4–5 hours post-cold exposure.
Timing of Exercise
- Best time: Right before your most cognitively demanding work of the day
- For most people, this means morning exercise
- Later-day exercise elevates cortisol and can disrupt sleep
- Performing exercise at a consistent time daily leverages the circadian system to build anticipatory arousal and reduce friction
Memory Decline and Aging
- Noticeable memory hiccups often begin in the 50s or 60s, with significant individual variation
- Chronic stress and anxiety worsen memory at any age
- Longitudinal data (Swedish Women’s Study, published 2018):
- 300 women characterized as low/mid/high fitness in their 40s
- Followed