Matthews’ perception has taken his career in a new direction. Leaving aside his research on drug addiction, in 2013 he went to join K Toy’s laboratory at the Massachusetts Institute of Technology. A neurologist focused on understanding the neural basis of tie emotion, and he is one of the pioneers of optogenetics – a technology that uses genetically engineered proteins transmitted to brain cells to enable researchers to turn neurons on and off by turning on light through fibers. The method allows scientists to activate areas of the brain in real time and see how animals respond. “By the time I joined the lab, the optogenetics had really exploded and it opened up a lot more possibilities for what you could study,” says Matthews.
Equipped with this new technique, Matthews and Tye wanted to know how DRN neurons affected rats during social isolation. When the researchers stimulated the neurons, the animals were more likely Search for other rats. When they suppressed the same neurons, even isolated animals lost the desire for social interaction. It seems that Matthews and Tie invented the neural switch that controls the animal’s desire for social interaction. When their social desires are satisfied, they become detached and return.
Their discovery could change our understanding of loneliness. “Adopting this idea suggests that there are measures in place to help us maintain social contact in the same way to ensure that we maintain our food intake or water intake.” Matthews says. This suggests that it’s not very good to keep social contact – it’s a basic need that our brains are hard to find. It is already carried Studies on bees, Ants, rats and mice. “Without full-fledged social communication, survival is declining among the myriad species,” says Matthews.
In 2020, another MIT neuroscientist published a study showing that the human brain responds to social isolation in much the same way as the brain rat. Livia Tomova has recruited 40 volunteers and told them to turn on their smartphones, tablets and laptops and spend 10 hours in a room of their own. Volunteers could occupy themselves with puzzle books and writing materials, but they were not allowed access to any fiction that might have an indication of social interaction that could remove their isolation. If the volunteers needed to use the bathroom, they had to wear earmuffs that prevented them from hearing any conversations on the way. “We’re trying to create a situation where people don’t really get any input,” said Tomova, now at Cambridge University.
Optogenetics is not too aggressive for human use, but instead Tomova took FMRI scans of the brains of her volunteers. When isolated volunteers were shown pictures of social cues, regions of their brains were sharply connected and glowed with similar activity. Pictures of food are shown. The area of the brain that Tomova focused on is rich in dopamine neurons, which drive inspiration and expectation from the world around us. These neurons are activated in anticipation when our brain expects any beneficial activity – such as eating or social interaction. But if we don’t get these interactions, our brain feels negative, like thirst.
Tomova says this could explain the negative consequences of long-term isolation. “If you are under prolonged stress, the same adaptations that are healthy and necessary in the first place will actually be detrimental because they are not designed as a long-term state.”