Tools to Enhance Working Memory & Attention

High-Level Overview

In this solo episode, Andrew Huberman explains working memory, the brain's ability to hold small amounts of information in mind for short periods, use it, and then let it go. He contrasts it with short- and long-term memory, which depend on neuroplasticity, and explains that working memory is closely tied to attention and depends heavily on dopamine released in the prefrontal cortex. Listeners take two working memory tests during the episode, and Huberman explains how their score may roughly reflect their baseline dopamine in the relevant circuits. He then reviews a crucial finding: dopamine and working memory follow an inverted U-shaped relationship, so more dopamine helps people who start low but can hurt people who start high.

The second half focuses on tools: non-sleep deep rest and yoga nidra, deliberate cold exposure, binaural beats, the supplements L-tyrosine and Mucuna pruriens, and prescription options. The tone is clear, patient and practical, with frequent safety caveats. The episode flows from basic memory science to an interactive self-test to a graded menu of zero-cost behavioral tools, supplements and medications.

The Discussion Explores:

• How long-term, short-term and working memory differ, and why working memory doesn't rely on neuroplasticity
• Forms of neuroplasticity: long-term potentiation, long-term depression and neurogenesis
• Two on-air working memory tests and what your score may say about your dopamine
• The prefrontal cortex, dopamine and the inverted U-shaped relationship with working memory
• Ignoring distractions versus task switching, and the circuits behind each
• Zero-cost tools: NSDR, yoga nidra and deliberate cold exposure
• Binaural beats as a non-pharmacological aid
• L-tyrosine, Mucuna pruriens and prescription dopamine drugs, with caveats

Deep Dive into Main Ideas

Long-Term, Short-Term and Working Memory

Huberman first describes long-term memory, which comes in two forms: declarative memories, like facts you can state, and procedural memories, like riding a bike or tying your shoes. The hippocampus, a seahorse-shaped structure on each side of the brain, is essential for forming and accessing long-term memories. Short-term memories last minutes to hours, and only a fraction of what we experience enters short-term memory, and only a fraction of that becomes long-term memory. The hippocampus helps pass short-term memories into long-term storage, and some long-term memories are distributed into the neocortex. As always, he emphasizes that memory is a network phenomenon, not the job of one brain area.

Forming short- and long-term memories relies on neuroplasticity, the nervous system's ability to change with experience. The main forms are long-term potentiation, the strengthening of connections between neurons that fire together, captured in the phrase "fire together, wire together," which he notes came from his Stanford colleague Carla Shatz rather than Donald Hebb; and long-term depression, the weakening or removal of connections, which has nothing to do with clinical depression. Neurogenesis, the birth of new neurons, does occur in adults, possibly in the hippocampus's dentate gyrus, but Huberman stresses it is an infinitesimally small contributor to learning compared with strengthening and weakening existing connections.

What Working Memory Is

In stark contrast, "Working memory, as far as we know, does not involve neuroplasticity," Huberman explains. Instead, it reflects a neural circuit running the same algorithm over and over on new information, then deliberately discarding it. It's what lets you sequence the steps of your morning, drinking water, making coffee, putting on shoes, heading out for a run, and then forget those steps so you can focus on what's next. Working memory is involved in essentially everything we do from waking to sleep, and people who lack it struggle to sequence activities, needing even more help than people with little long-term memory. It is tightly linked to attention at the level of both circuits and chemistry.

Testing Your Working Memory

Huberman runs listeners through two audio tests. In the first, he reads strings of letters, like J-K-Z-P-I, and asks listeners to recall them. A couple of minutes later, he asks for the first string again, and most people remember zero to two letters. That's working memory doing its job: holding information only as long as needed, then discarding it. Working memory, he notes, is as much about forgetting as remembering.

The second test involves six sentences, such as "Real estate costs are going up" and "Some reptiles eat only once a year," after which listeners recall the final word of each. Three to four is average. For this discussion, he divides people into two groups: remembering three to six final words indicates a high working memory span, while zero to two indicates a low span. He stresses that a low score is not diagnostic of Parkinson's or any disease and isn't cause for alarm; it's simply a useful baseline for choosing tools.

Dopamine and the Prefrontal Cortex

Key hubs for working memory are the prefrontal cortex, just behind the forehead, and dopamine-producing neurons in the brainstem that project to it, the mesocortical pathway. Dopamine is about motivation and drive, not just pleasure; too much can contribute to mania or addiction, too little to movement problems like Parkinson's. Huberman describes a 2008 PET imaging study by Roshan Cools, Mark D'Esposito and colleagues showing that people with high working memory spans had more dopamine available for release in the prefrontal cortex, and those with low spans had less. A classic study by Brozoski, Brown, Rosvold and Goldman showed that adding dopamine to the prefrontal cortex increased working memory capacity, while adding norepinephrine or serotonin had no effect, and other experiments found that depleting dopamine worsened performance. The literature consistently points to dopamine as the capacity-limiting neuromodulator for working memory.

The Inverted U: More Isn't Always Better

Huberman repeats a crucial caveat: "It is not always the case that increasing the amount of dopamine transmission in the frontal cortex leads to improvements in working memory." In studies from D'Esposito's lab at UC Berkeley and others, people took the dopamine agonist bromocriptine at low, moderate or high doses and were tested 90 minutes later. Those who started with low working memory spans improved significantly, recalling four to six sentence endings instead of zero to three. Those who started high saw little or no benefit at low or moderate doses, and at the highest dose their performance actually dropped below baseline.

This inverted U-shaped relationship means low dopamine yields low working memory, optimal dopamine yields peak performance, and too much dopamine degrades it. That's why he asks listeners to know their baseline before trying dopamine-boosting tools, and why the same tool might help one person and hurt another.

Two Components: Ignoring Distractions and Task Switching

Working memory depends on at least two abilities. One is filtering out distractors, whether in the environment or on your own body, which relies largely on dopamine projections to the prefrontal cortex. The other is switching between tasks or interleaving them, like talking on the phone while tying your shoes, which relies on dopamine projections to the basal ganglia, circuits that issue go and no-go commands for starting and stopping actions. Selectively boosting dopamine to one or the other pathway improves the corresponding ability. Huberman connects this to rising difficulties with focus and attention, including ADHD in kids and adults, possibly related to overuse of phones and social media, though a causal link hasn't been established.

Zero-Cost Tools: NSDR, Yoga Nidra and Cold Exposure

The first-line behavioral tool Huberman recommends is non-sleep deep rest, or NSDR, a term he coined for a stripped-down version of yoga nidra without intentions or mystical language. Both involve lying down and following an audio script with long exhale breathing and deliberate relaxation of the face and body, while trying not to fall asleep. In one study, an hour-plus yoga nidra session increased baseline dopamine in the basal ganglia and other structures by as much as 60 percent compared with a control. Other studies show improved performance on cognitive tasks with a working memory element. Free scripts are available on YouTube, from apps like Waking Up, and from teachers such as Kelly Boys, from about 8 to 45 minutes. He suggests trying 20 to 30 minutes at first; he himself usually does 10.

Deliberate cold exposure is another option. In one study, people sitting in water in the low 60s Fahrenheit up to their necks for about 45 minutes or longer showed large, long-lasting increases in epinephrine, norepinephrine and dopamine that persisted for hours. Colder water produces similar effects much faster, so most people use 30 seconds to three minutes in a cold shower, plunge or natural water, choosing a temperature that is safe but uncomfortable enough that you want to get out. Studies haven't directly tested cold exposure before working memory tasks, but Huberman thinks doing it 30 to 60 minutes beforehand is mechanistically logical, and many people report better focus and needing less caffeine. He warns emphatically never to combine hyperventilation or breath holding with cold water, because people can pass out and die. People with high working memory spans can still experiment with these tools, since they carry little risk, but should notice if performance drops. He favors these tools because they produce large, long-lasting increases in baseline dopamine rather than brief spikes like those from video games, sex or chocolate.

Binaural Beats

Binaural beats involve playing slightly different sound frequencies in each ear through headphones so the brain tends to entrain to the difference. A 2019 study of 24 participants found 40 Hz binaural beats produced small to moderate but significant improvements on working memory tasks, and a 2016 study found 15 Hz beats improved visual-spatial working memory and increased information transfer between brain regions. Listening during or before a task both seemed to work. Huberman notes it's unknown whether these effects involve dopamine, but free or low-cost binaural beat tools are easy to find.

Supplements: L-Tyrosine and Mucuna Pruriens

L-tyrosine, an amino acid precursor to dopamine, improved working memory in a multitasking environment in a 1999 study by Thomas and colleagues. The improvements were statistically significant but modest, and the dose was very high: 150 milligrams per kilogram of body weight, which would be about 15 grams for Huberman at roughly 100 kilograms. He says he can't in good conscience recommend that, since he feels a meaningful boost in alertness from just 500 milligrams. His advice is to talk to a healthcare provider first, then look for the minimal effective dose, perhaps 250 milligrams for someone around 50 kilograms or 500 milligrams for someone heavier, and to watch for a crash three to four hours later.

Mucuna pruriens, from a velvety bean, is essentially L-DOPA, the prescription drug used for Parkinson's, and potently increases dopamine. Studies have used one to five grams, but Huberman strongly advises talking to a doctor first and starting with 250 to 500 milligrams to find the minimal effective dose. He cautions against using any supplement to treat Parkinson's or other conditions without medical guidance.

Prescription Options and Better Living

Bromocriptine, a prescription dopamine agonist peaking at about 90 minutes, improves working memory in people with low spans and is sometimes prescribed off label by neurologists for conditions like traumatic brain injury, Parkinson's, dementia and ADHD, all of which involve working memory deficits. ADHD medications such as Adderall and Ritalin raise dopamine and norepinephrine, and modafinil works differently to improve cognitive performance; he covers these in his ADHD episodes. Huberman takes a firm stance that these amphetamine-based drugs are probably overprescribed but genuinely help certain children and adults, including by promoting neuroplasticity in focus circuits. He encourages people to bring knowledge of behavioral, nutritional and supplement tools to conversations with their physicians, since some people manage subclinical focus problems or reduce their medication with them. He quotes a physician friend: "better living through chemistry still requires better living."

Conclusion

Huberman's key message is that working memory is a distinct, remarkable brain function built for using information briefly and then discarding it, and that dopamine in the prefrontal cortex largely sets its capacity. Because the dopamine-working memory relationship is an inverted U, knowing your baseline, even through a simple test like his six-sentence task, helps you choose tools wisely. For people with lower working memory, zero-cost options like NSDR, yoga nidra and deliberate cold exposure offer long-lasting dopamine boosts with little risk, binaural beats may add a modest edge, and supplements or prescriptions can help under proper guidance. It's a practical, carefully caveated guide for anyone who wants sharper focus and better control of their attention.

This is a summary of "Tools to Enhance Working Memory & Attention" from Huberman Lab, giving you the GIST so you can decide if you want the REST. Listen to the full episode.