Andrew Huberman: Professor of neurobiology and ophthalmology at Stanford School of Medicine and host of the Huberman Lab podcast. This is a solo episode.
What this episode covers
Andrew Huberman dedicates this solo episode to working memory, the brain's ability to hold small amounts of information briefly and then deliberately discard it, and its tight link to attention. He distinguishes working memory from short- and long-term memory, runs the listener through live working memory tests, and explains that working memory capacity tracks baseline dopamine levels in the prefrontal cortex following an inverted-U curve. He then walks through a tiered set of tools to raise dopamine and improve working memory: behavioral protocols (NSDR/Yoga Nidra, deliberate cold exposure, binaural beats), over-the-counter supplements (L-tyrosine, Mucuna pruriens), and prescription dopamine agonists (bromocriptine, Adderall, Ritalin, modafinil). Throughout he stresses that more dopamine is not always better and urges medical consultation before any pharmacology.
Recommended on this episode
L-Tyrosine
“at a subjective level, I can feel a meaningful increase in alertness and focus from 500 milligrams of L-tyrosine”— Andrew Huberman
Also referenced (named, not recommended)
Waking Up
Waking Up
“yoga nidra scripts or protocols, as well as NSDR scripts or protocols, are available totally zero cost. You can find them certainly on apps like Waking Up”— Andrew Huberman
Why We Sleep
Matthew Walker
“I have some plans in the not-too-distant future to collaborate with Matthew Walker, the author of the book Why We Sleep”— Andrew Huberman
Mucuna Pruriens
“Mucuna pruriens is essentially the equivalent of L-dopa. L-dopa is a prescription drug, as I mentioned before. And Mucuna pruriens potently increases dopamine”— Andrew Huberman
Bromocriptine
“drugs like bromocriptine which we know are so-called dopamine agonist. An agonist is a drug that has the consequence of increasing the amount of a given neurochemical”— Andrew Huberman
Adderall
“the drugs that increase dopamine and norepinephrine for the treatment of ADHD... things like Adderall, things like Ritalin”— Andrew Huberman
Ritalin
“things like Ritalin, which by the way is quite different than Adderall in terms of how much dopamine relative to norepinephrine it causes the increase of”— Andrew Huberman
Modafinil
“I also talk a little bit about modafinil, which is a entirely different category of drug known to improve cognitive performance in some cases”— Andrew Huberman
Big reveals from this episode
- Stresses more dopamine does NOT always equal better working memory, the relationship is an inverted-U.
- In high working memory individuals, the highest dose of bromocriptine actually degraded performance below baseline.
- Cites a study where a Yoga Nidra protocol raised baseline dopamine by as much as 60%.
- Got 'wide-eyed' at the L-tyrosine study dose: 150 mg/kg, roughly 15 grams for him, which he can't recommend.
- Takes a firm, admittedly controversial stand that some children and adults have a strong case to take dopamine-increasing compounds.
- Acknowledges ADHD amphetamine medications are probably over-prescribed, yet genuinely benefit many people.
Worth remembering
- Working memory, unlike short- and long-term memory, does not appear to rely on neuroplasticity, information is intentionally discarded.
- The phrase 'fire together, wire together' was coined by Carla Shatz, not Donald Hebb as commonly believed.
- Adult neurogenesis is real but infinitesimally small compared with LTP and LTD as a mechanism for memory.
- Dopamine, and perhaps only dopamine, regulates working memory capacity, norepinephrine and serotonin had no effect.
- Task switching depends on dopamine to the basal ganglia, while ruling out distractors depends on dopamine to the prefrontal cortex.
- Cold water exposure (low 40s to low 60s Fahrenheit) can double or triple circulating dopamine for several hours.
- Thirty seconds in 45-degree water can spike catecholamines as much as 45 minutes in 60-degree water.
- Mucuna pruriens is a velvety bean equivalent to roughly 99% L-dopa, the dopamine precursor prescribed for Parkinson's.
- Never combine breath-holding or hyperventilation with cold exposure, you can pass out and die.