In a new brain imaging study, a team of neuroscientists at Oxford University in England found functional differences in the brains of those who were motivated compared to those who were apathetic.
“We know that in some cases people can become pathologically apathetic, for example after a stroke or with Alzheimer’s disease,” said Dr. Masud Husain, a professor of neurology and cognitive neuroscience. “Many such patients can be physically capable. Yet they can become so demotivated they won’t be bothered to care for themselves, even though they’re not depressed.
“By studying healthy people, we wanted to find out whether any differences in their brains might shed light on apathy.”
The scientists recruited 40 healthy volunteers, then asked them to complete a questionnaire that scored them on how motivated they were. They were then asked to play a game in which they were made offers, each with a different level of reward and physical effort required to win the reward. Unsurprisingly, offers with high rewards requiring low effort were usually accepted, while low rewards requiring high effort were less popular, the scientists report.
When volunteers played the game in an MRI machine, a surprising finding emerged, according to the researchers.
Although apathetic people were less likely to accept offers involving a lot of effort, one area of their brains actually showed more activity than in motivated individuals: The premotor cortex.
A key area involved in taking actions, the premotor cortex becomes active just before those areas of the brain that control our movement. Paradoxically, in more apathetic people it was more active when they chose to take an offer than it was in motivated people, the study found.
“We expected to see less activity because they were less likely to accept effortful choices but we found the opposite,” Husain said. “We thought that this might be because their brain structure is less efficient, so it’s more of an effort for apathetic people to turn decisions into actions.
“Using our brain scanning techniques, we found that connections in the front part of the brains of apathetic people are less effective,” he continued. “The brain uses around a fifth of the energy you’re burning each day. If it takes more energy to plan an action, it becomes more costly for apathetic people to make actions. Their brains have to make more effort.”
The researcher added that “as far as we know, this is the first time that anyone has found a biological basis for apathy in healthy people.”
“It doesn’t account for apathy in everyone, but by giving us more information about the brain processes underlying normal motivation, it helps us understand better how we might find a treatment for those pathological conditions of extreme apathy,” he added.
Source: Oxford University