Mapping the Brain to Understand What Makes Us Human

Depression. Anxiety. Aphasia. These uniquely human diseases affect millions of Americans each year and, for some, cannot be resolved with existing drugs or therapies. 

Neurosurgeon Edward Chang, MD ’04, of the UCSF Weill Institute for Neurosciences, wonders whether such troubles stem from flawed brain circuitry and if identifying flaws in that circuitry – and correcting them – could provide relief to people suffering from some of the most devastating speech and psychiatric disorders. 

He has a unique opportunity to find out: Every year, dozens of patients with complex, near-weekly seizures visit Chang to receive specialized surgical treatment – a last resort when a treatment for their epilepsy is unusually elusive. 

An intricate network of electrodes is surgically implanted on the surface of the brain, allowing Chang and his colleagues to determine which region of the patient's brain triggers the seizures, in the hope that the seizures can be curbed through surgery. 

But these electrodes, implanted out of medical necessity, happen to be in parts of the brain that researchers also want to examine because of their impact on depression and anxiety and their role in controlling speech. 

In other words, chance has given Chang and his team access to an ideal pool of research participants. With patients’ consent, he can study their moods, emotions, and speech as they undergo treatment. 

“It’s remarkable and humbling to see the interest patients have in participating,” says Heather Dawes, PhD, project co-director. “They know it’s unlikely to benefit them directly, but they take the time to work with us anyway.” 

Chang hopes that by pinpointing the networks in the brain that go awry in epilepsy, anxiety, and depression, he can find a way to remodel them to restore healthy functioning. And by applying what he’s learned about how the brain controls speech, he might be able to translate thought into speech for paralyzed patients. 

This is uncharted territory – bridging psychiatry, neurology, and engineering – that could one day lead to an implanted device that emits a minute impulse to shift brain circuity from unhealthy to healthy. Such a device could enable paralyzed patients to speak and move – and help the brain “unlearn” depression and anxiety. 

 Edward Chang is chair of the UCSF Department of Neurological Surgery, the Jeanne Robertson Distinguished Professor of Psychiatry, co-director of the UCSF/UC Berkeley Center for Neural Engineering and Prostheses, and a Bowes Biomedical Investigator.