Researchers find that targeting specific regions of the brain with ultrasound may increase a person’s mood.
A study recently published in the journal Frontiers in Human Neuroscience suggests that targeting a region of the prefrontal cortex with transcranial focused ultrasound (tFUS) — a new ultrasound technique — may temporarily elevate mood.
The findings could both open the door to further mood-enhancing techniques and support further research into consciousness.
tFUS is a developing technique that allows researchers to affect the pattern of a person’s brain waves. Influencing brain waves in this way can generate different cognitive effects.
Other techniques for changing brain waves include transcranial magnetic stimulation and transcranial direct current stimulation. tFUS has a number of advantages over these methods, primarily that it enables a researcher to access deeper parts of an individual’s brain with more precision.
As the authors of the present study report, past experiments in animals have shown that tFUS modulates neuronal activity; also, studies in humans have demonstrated that it temporarily alters activity in various parts of the brain.
A possible clinical application of tFUS is the treatment of psychiatric and neurological diseases.
As such, the authors of the present study wanted to see what effect tFUS would have on a part of the brain associated with mood and other affective responses — the right inferior frontal gyrus (rIFG).
To go about this, the researchers conducted two experiments in healthy volunteers. The first looked at the effects of tFUS on mood. The second experiment also looked at mood, but additionally, it measured the effects of tFUS on brain activity related to emotion and mood regulation.
For the first experiment, the team recruited 51 volunteers, including 27 females and 24 males, with a mean age of 19.7 years. The researchers split them into two groups.
The first group received 30 seconds of tFUS targeting the rIFG, while the second acted as a placebo group. The experiment was set up so that neither the participants nor the researchers could know who received tFUS and who received the placebo.
The team informed the participants that the study’s aim was to look at the effects of tFUS on mood, but they did not tell them whether the technique was likely to make them feel better or worse.
The volunteers were asked to fill in mood surveys — before the experiment and 10, 20, and 30 minutes afterward.
The researchers found that participants who had received tFUS reported an increase in their mood 20 and 30 minutes after the ultrasound.
For the second experiment, the team recruited nine volunteers — four females and five males — with a mean age of 19.2 years. Each received the tFUS treatment, but before and after, their brain activity was measured using functional MRI. The participants also completed the mood surveys.
The team determined that the tFUS treatment had altered brain waves in the regions of the brain associated with mood. The ultrasound had slowed the activity of the brain.
As the authors note, previous research indicates that elevated brain activity in these regions can increase rumination and the person’s ability to self-regulate emotions — both of which are often associated with lower moods.
As in the first experiment, the participants in the second experiment reported an increase in mood following the ultrasound.
As the authors explain, their study is significant because it demonstrates that tFUS can affect the mood of a healthy person, whereas previous research focused on people with existing neurological or psychiatric conditions.
However, the precise mechanisms of how and why changes in a person’s brain waves affect their mood are still to be revealed. As the authors acknowledge, “The mechanisms by which tFUS affects neural activity remain unknown, and more research is needed.”
The authors hope that the research might help scientists mobilize the way that brain cells change in response to internal or external factors — known as the brain’s “plasticity.”
As the lead author of the study, Joseph L. Sanguinetti, Ph.D., an adjunct professor at the University of Arizona, Tucson, says, “We’re not trying to stimulate neurons to fire, nor simply activate pleasure areas, but to modulate plasticity and enable brain circuits to ‘re-tune’ toward being more mindful ‘in the moment.’”