I recently co-founded Nudge with Fred Ehrsam, a company with the goal of creating hardware that dramatically improves the daily lived experience of people everywhere. We're using ultrasound to safely and non-invasively measure and modulate brain activity at high resolution — we see huge promise for both those struggling with mental health challenges and eventually people who are generally healthy and want to enhance their everyday life. Ultimately, practically everything that we care about is in some way tied to the quality of our state of mind - and few technologies can interface with it directly, especially in a way that’s beneficial over the long-run.
While it's hard to predict the full range of possibilities we'll see from our device, we think the highest impact capabilities will be increasing wellbeing, agency over how we choose to spend our time, and the ability to think clearly and learn quickly. While we have a long way to go on delivering these capabilities consistently and at scale, we're starting to see real traction on the science and engineering that would enable such a device and are working in earnest to make it a reality.
Non-invasive (without a surgical implant) brain stimulation over the past 5 years has already demonstrated the capacity to change people's lives for the better. Magnetic stimulation, namely an optimized protocol of rTMS first developed at Stanford, has shown ~80% efficacy in a randomized-controlled trial at treating intractable forms of depression during only a week of intensive treatment. There are reports of the treatment being transformative for many who participate, a true "before and after" moment. Ultrasound is starting to show the signs of a similar inflection point: we're seeing results of a single, under 30 minute treatment that can enable those addicted to opiates (and who have tried many other forms of standard treatment) to stop using for a month or more. From an article on the first results of the study, patients are reporting long-term effects. While we still need to see how results hold up in a fully randomized, controlled trial, it's an exciting first look at what may be to come:
Part of the power of this technology is that once it demonstrates efficacy for a given treatment, this implies a more generalized set of effects — not only can we target a brain area responsible for the reward learning implicated in addiction, but others which may help treat depression or pain, simply by changing the input parameters and targeting. In fact, we're already seeing treatment of chronic pain in a neighboring region show strong effectiveness in a single 40-minute treatment in a controlled trial.
There are many ways to interface with the brain, both invasively and non-invasively, but very few are truly safe, scalable, and have compelling use cases. The primary physical ways to interface with the brain are optically (using light to either measure the properties of or affect a neuron's state), magnetically (as mentioned above), electrically (with brain implants like the current brain-computer interfaces used in patients with movement disorders), and acoustically (imaging and stimulating through sound or ultrasound). Optical approaches are limited by the depth light can penetrate into the brain to either implants or surface level brain imaging, potent electrical interfacing requires implantation, and magnetic approaches, while non-invasive, can't be miniaturized and used to target deep brain regions due to physical constraints on the focusing of magnetic fields. Only ultrasound has the overlapping advantages of being incredibly safe on the body (there are decades of research on using low-intensity ultrasound to image fetuses in the womb), can be focused using beamforming to target deep brain regions of millimeters in size, can be used for structural and functional brain imaging, and has hardware that can be miniaturized and scaled without needing an implant.
While ultrasound's potential as a treatment for mental health diagnoses is just starting to become apparent, we think everyone could eventually benefit from the technology. While over the years I've been blown away by the progress on brain-computer interfaces, faster control of a computer cursor or typing with my thoughts isn't nearly as important to me as my ability to focus and learn effectively, regulate my sleep or stress levels, or explore new states of mind. On the imaging side, I'm excited for brain interfaces that create motifs for communication that are only enabled by understanding circuit-level activity — revolutions in computing happen when the medium creates new gestures for interfacing, rather than just speeding up old ones.
We have a lot of work to do both scientifically and technically to make the vision of this technology a reality. It's something of an open secret in the field that there are still many hard problems which have plagued researchers for years: incomplete models for the mechanism of action, inaccuracies in acoustic simulation, bulky and/or imprecise transducer hardware, a lack of clear feedback from brain imaging, differences in neuroanatomy or function across individuals, and a lack of definitive parameters to use. Along with the tantalizing recent results in humans for addiction, chronic pain and more, we're starting to gain a foothold in solving many of them in the last 6 months — some solutions coming from the broader research community and some already at Nudge. I ultimately believe that for a compelling product to emerge from this approach we'll need to solve all of these problems at once, and in the same company which has the capacity to scale the product that comes out. If you're an exceptional researcher or engineer and want to work on technically challenging problems and a meaningful mission, please reach out.