When neurologist Josef Parvizi electrically stimulated a portion of his epileptic patient’s brain, the subject reported a striking mood change, along with some physical effects: He reported feeling a vibration or shakiness in his chest, his heart rate sped up significantly and he gained a foreboding sense that he was going to face something challenging. He distinctly felt “positive” about the trial, however, and was determined to overcome the obstacle.
At the time, Parvizi and his team of Stanford School of Medicine researchers were attempting to find the source of their patient’s seizures, intending to remove the responsible tissue as long as the excision would not impair his well-being. They turned to this procedure because the patient had refractory epilepsy, meaning he had not gone without a seizure in over a year, after multiple pharmaceutical treatments. To find the affected part, they implanted electrodes into the man’s brain and stimulated specific areas, then asked him questions about his emotions and thoughts. This was when they got his unexpected answers.
Afterward Parvizi stimulated the same spot in another patient’s brain. That person, to his surprise, reported the same raft of physical symptoms, along with feeling he was about to face a challenge but nonetheless had the strength to face it.
The researchers had accidently discovered the location in the brain that triggers a person’s will to persevere. Such resolve, the ability to endure psychological and physical pain to overcome a challenge, varies from person to person. For instance, people who are depressed often find themselves so deprived of the ability to persevere that they cannot get out of bed.
Following up, the researchers conducted imaging experiments to learn more about the area. They found that the specific spot sits at the core of a particular neuronal network, where it links the anterior midcingulate cortex (aMCC), an area inside the front of the brain involved in processing executive functions, to many other regions of the brain. “We [now] know feelings and functions are not and cannot be centered in [just one] area of the brain, but [lie within] a distributed network,” Parvizi says. In contrast to the idea that emotions are located in a specific area of the brain, different parts of the brain actually have to work together to produce this particular state of mind. The findings were published online December 5 in Neuron.
The discovery could help researchers figure out new ways to induce persistence in those suffering with neurological disorders that have compromised their will to persevere. A long road of research lies between this finding and its potential clinical applications, however. We still have to study and refine the entire discovered connectivity map, and “figure out which parts of the network are more directly involved with the will to persevere,” says Soo Yeun Lee, a neuroscientist at Stanford University. Also, the investigators may well have trouble finding many people who are in a position to be studied and willing to allow invasive surgery. Nevertheless, Lee notes, the anatomical discovery suggests studying a brain region and network that have not been extensively observed for this effect before will be “very exciting.”