Deep-Brain Recordings May Show Where Unhappiness @Lives joerogan https://t.co/Dk81HRZCoX
The spiral into such a mood may occur in a brain network that connects two key regions involved with memory and negative emotions, says psychiatrist Vikaas Sohal at the University of California, San Francisco. In a study he co-authored, published in November in Cell, Sohal says he was able to tell if someone’s mood was getting worse just by looking at whether this network was active or not.
Psychiatrists have previously used MRI scans to probe the human brain and the world of emotions within it. This technology can show how brain activity changes within a few seconds, but the brain tends to work a lot faster than that—neurons can fire dozens of times a second. MRI readings might miss things that happen too quickly. Implanted electrodes, however, can measure changes in brain activity up to 1,000 times a second. So when U.C.S.F. neurosurgeon Edward Chang popped into Sohal’s office with an idea to use internal electrodes to elucidate the neurological underpinnings of mood, Sohal was delighted.
The brain surgery needed to implant electrodes is too risky to perform on healthy individuals for a study like this—but Chang works on epilepsy patients who need them anyway. When other treatments do not work, temporarily implanted electrodes can show what part of the brain is causing seizures, allowing Chang to cut that section out during surgery. By asking such patients to report their moods every few hours, the team hoped they could use the electrodes to get a rare window into emotion and the deep brain. “We know that mood is somewhere in the brain,” Sohal says. His goal was “to see if we can find patterns of activity that tell us what mood is.”
Chang implanted electrodes on the surfaces and inside the brains of 21 patients with epilepsy, recording the organs’ activity continuously for seven to 10 days. Then Sohal scoured the recordings for instances when electrodes in different parts of a brain showed identical measurements of electrical activity. “Electrical activity of the brain looks like wiggles” from each electrode when displayed on a graph, Sohal says. “You ask, ‘Okay, do the size of those wiggles and the locations of the peaks go up together in sync across two electrodes?’” If they do, it suggests those brain regions are communicating. “We call that a network,” Sohal says.