Technology might not be advanced enough yet to let people read someone else's mind, but researchers are at least inching closer to helping people to read and control their own. In a study presented last week at the Society for Neuroscience meeting in San Diego, scientists used a combination of brain-scanning and feedback techniques to train subjects to move a cursor up and down with their thoughts. The subjects could perform this task after just five minutes of training.
Brainstorm: This fMRI scan highlights areas that are most active during two thought processes: One (SMA) is active when subjects think about tennis, the other (PPA) lights up when they imagine roaming through a familiar space.
The scientists hope to use this information to help addicts learn to control their own brain states and, consequently, their cravings.
Scientists have previously shown that people can learn to consciously control their brain activity if they're shown their brain activity data in real time—a technique called real-time functional magnetic resonance imaging (fMRI). Researchers have used this technology effectively to teach people to control chronic pain and depression. They've been pursuing similar feedback methods to help drug users kick their addictions.
But these efforts have been difficult to put into practice. Part of the problem is that scientists have had to choose which part of the brain to focus on, based on existing knowledge of neuroscience. But that approach may miss out on areas that are also important for the particular function under study.
In addition, focusing on a limited region adds extra noise to the system—much like looking too closely at just one swatch of a Pointillist painting—the mix of odd colors doesn't make sense until you step back and see how the dots fit together. Psychologist Anna Rose Childress, Jeremy Magland, and their colleagues at the University of Pennsylvania have overcome this issue by designing a new system of whole-brain imaging and pairing it with an algorithm that let them determine which regions of the brain are most centrally involved in a certain thought process.
"I think it's very exciting, and I think it's likely to be just the tip of a large iceberg of possibilities," says Christopher deCharms, a neuroscientist and founder of Omneuron, a company dedicated to using real-time fMRI to visualize brain function. "It's a small case demonstration that you can do this and you can do it in real time."
Childress asked 11 healthy controls and three cocaine addicts to watch a feedback screen while alternately envisioning two 30-second scenarios: Repeatedly swatting a tennis ball to someone, and navigating from room to room in a familiar place. By analyzing whole-brain activity, researchers found that a part of the brain called the supplementary motor area was most active during an imagined game of tennis. They then linked this pattern to an upward movement of a computer cursor. They did the same with the navigation task, linking it to downward movement of the cursor. After four cycles or fewer—less than five minutes of training—the subjects had learned to alternate between the two states of mind, as well as associate each one with its corresponding cursor position. From there onward, they could move the cursor up or down with their thoughts.
"Conventional technology used up until now monitors a designated region of the brain, but the data tend to be noisy," Childress says. As a result, it's harder for researchers to determine what regions of the brain are important to control for feedback exercises. "But whole-brain information cancels out a lot of the noise."
The researchers found that both addicts and healthy people could control their state of mind equally well, something Childress says is encouraging for future studies. "The patients who have trouble controlling their craving could still demonstrate control over this sort of non-emotional test," she says. That confirms what earlier studies had suggested: Addicts' cognitive control issues are not linked to more general thinking, but instead limited to more emotionally charged thoughts, like cravings.
However, Childress's team will need to develop specialized tasks to figure out how to apply this to addiction and other disorders. For therapy, "You really need feedback from localized regions that have to do with their disease, and have people learn to control them," says Rainer Goebel, a professor of psychology at the University of Maastricht in the Netherlands who has done similar work with depression patients.
The University of Pennsylvania researchers are now developing just such a training program. For example, researchers might show cocaine addicts images or videos that involve stereotyped cocaine images, classify the brain region, and then use brain training to teach people how to dampen the activity in that part of the brain.
By Lauren Gravitz
From Technology Review