An incredible new study suggests that low-intensity ultrasound can be used to target very specific brain regions and alter an animal's decision-making processes. The technique, demonstrated in macaques monkeys, prompts actual behavioral changes using non-invasive ultrasound waves.
It is only recently that researchers have begun exploring the effects of low-intensity ultrasound on the brain. Although it is commonly known for its imaging potential, ultrasonic waves can also be highly targeted to modulate brain activity. One exciting human trial is currently underway investigating targeted ultrasound as a potential treatment for Alzheimer's and dementia, while a fascinating case study published in 2016 demonstrated the technology stimulating the neurons of a young coma patient, essentially "jump-starting" their brain.
"Ultrasound neurostimulation is an early-stage, non-invasive therapeutic technology that has the potential to improve the lives of millions of patients with mental health conditions by stimulating brain tissues with millimeter accuracy," explains Elsa Fouragnan, from the University of Plymouth and lead scientist on the new study.
The research focused on a cognitive process called counterfactual thinking. This is a part of our decision making processes where we evaluate scenarios that are alternative to our current experience. The researchers give the example of imagining the alternative experience of spending time outside in the sun while working inside the confines of an office.
This specific cognitive process is vital in helping us assess all our available options and choosing the most positive future action. Some scientists hypothesize that psychiatric patients demonstrating repetitive dysfunctional behaviors suffer from irregular counterfactual cognitive processes. The new research set out to home in on where exactly in the brain this cognitive process occurs, and whether targeted low-intensity ultrasound can modulate the process.
"This is a really exciting study for two main reasons – firstly because we discovered that the cingulate cortex is crucial to help switch to better alternatives, and secondly because low-intensity ultrasound can be used to reversibly change brain activity in a very precise part of the brain," says Fouragnan.
Studying the behavior of four macaques monkeys, the researchers revealed neuronal activity in the anterior cingulate cortex is vital to effective counterfactual thinking. Low-intensity ultrasound was then used to effectively disrupt neuronal activity in that brain region, resulting in the animals displaying different decision-making outcomes.
It's still very early days for this kind of research, but Fouragnan is hopeful the work can move into human trials very soon.
"Presently, neuromodulation techniques do exist for humans, to help people with conditions such as major depression or Parkinson's," he says. "But there are no techniques that have this level of accuracy while remaining non-invasive."
The new study was published in the journal Nature Neuroscience.
Source: University of Plymouth