Neuroscientists Identify Mechanism for‘Handshake Agreement’ in the Brain

By James Devitt

In decision-making, the brain engages in a “handshake” agreement between neurons, reports a research team that included NYU’s Bijan Pesaran, assistant professor at the Center for Neural Science, in a study published in the journal Nature this spring.

      The researchers focused on the cortex, the part of the brain where language, memories, and awareness of the outside world develop, and found that when choices are open, the brain’s frontal and parietal cortices relay clear signals back and forth. By contrast, when a decision and the path to execute it are dictated, the correlation between these regions is significantly weaker.

      “We showed how two areas of the brain communicate with each other when we make choices,” Pesaran explains. “Groups of neurons in each area seemed to be shaking hands, agreeing on what to do. Making decisions can be surprisingly hard. Our study suggests one reason for this is that different brain areas need to work together—they need to cooperate.”

      The scientists on the study, which grew out of the California Institute of Technology, where Pesaran had been a post-doctoral fellow, pinpointed one particular circuit that activates your ability to execute a decision—a finding that may help drive research in neural prosthetics and in how unhealthy decisions are made. The study’s senior researcher was Richard Andersen, a professor of neuroscience at the California Institute of Technology.

      The implications for this research are manifold, with Andersen noting that mental illness, aging, fatigue, and addiction can drive unhealthy choices. Once the regions of the brain responsible for free choice are deciphered, poor decision making may also be better understood.