Unlike cancer, brain diseases like epilepsy, Alzheimer’s disease, or depression don't tend to have easily measured biomarkers that could help doctors tailor treatments, or that could help researchers develop more effective drugs. So in neurology and psychiatry, the precision medicine revolution hasn't really arrived yet. But Beacon Biosignals, where Harry's guest Jacob Donoghue is the co-founder and CEO, is trying to change that. Beacon is focused on making electroencephalography into a more reliable and useful data source for diagnosing and treating neurological disease. EEG has been a common medical tool for almost 100 years, but interpreting an EEG readout is slow and expensive—all of which makes it the perfect candidate for machine learning analysis. By using computation to peer deeper into EEG data, Donoghue thinks it should be possible to identify subtypes of problems like epilepsy or Alzheimer’s, and help neurologists understand which patients will respond best to which therapies. On top of that, better EEG measurements could also give drug developers and regulators more clinical endpoints to measure when they’re trying to evaluate the safety and efficacy of new drugs for CNS diseases. If Beacon’s vision comes true, the precision medicine revolution might finally start to reach the brain.