Researchers find that ultrasound targeting specific regions of the brain can increase a person’s mood.
A recent study published in the journal Frontiers in Human Neuroscience indicates that targeting a region of the prefrontal cortex with transcranial-focused ultrasound (tFUS)— a new ultrasound technique — can elevate mood temporarily.
The findings could both open the door to further mood-enhancing techniques and support further research into consciousness.
Ultrasound techniques
TFUS is a developmental technique that helps researchers to control a person’s brain wave pattern. In this way controlling brain waves can create different cognitive effects.
Other methods to modify brain waves include transcranial magnetic stimulation and direct-current transcranial stimulation. TFUS has several advantages over these methods, namely by allowing a researcher to more accurately enter deeper parts of an individual’s brain.
As mentioned by the authors of this research, past animal experiments have shown that tFUS modulates neuronal activity; also, human studies have shown that it temporarily changes activity in different parts of the brain.
Diagnosis of psychological and neurological disorders is one potential clinical use of tFUS.
As such, the authors of this study wanted to see what effect tFUS would have on a part of the brain linked to mood and other affective responses— the right inferior frontal gyrus (rIFG).
Measuring mood and brain waves
The researchers performed two studies on healthy volunteers to achieve this. The former looked at the mood effects of tFUS. The second experiment also looked at mood, but in addition it tested the impact of tFUS on brain activity related to regulating emotion and mood.
The team recruited 51 volunteers for the first trial, including 27 females and 24 males, with a mean age of 19.7 years. The researchers are splitting these into two classes.
The first group received 30 seconds of rIFG-targeted tFUS, while the second group behaved as placebo. The experiment was set up in such a way that neither the participants nor the researchers could know who got tFUS and who got the placebo.
The team told the participants that the aim of the research was to look at the mood-related effects of tFUS, but they did not tell them whether the treatment was likely to make them feel better or worse.
The volunteers were asked to complete mood surveys — 10, 20, and 30 minutes later before the experiment.
Researchers found that participants receiving tFUS registered an improvement in their mood after the ultrasound for 20 and 30 minutes.
The team recruited nine volunteers for the second experiment— four females and five males— with a mean age of 19.2 years. Each was treated with tFUS but their brain activity was assessed using functional MRI before and after. The Mood Surveys were also completed by participants.
The team concluded the tFUS therapy had changed brain waves in mood-related regions of the brain. The mri had delayed brain activity.
As the authors note, earlier research indicates that increased brain activity in these regions can increase rumination and the ability of the individual 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.
Future research
As the authors clarify, their study is important because it indicates that tFUS can influence a healthy person’s mood, whereas previous research has focused on individuals with severe neurological or psychiatric conditions.
However, it is still to be discovered the exact mechanisms of how and why changes in a person’s brain waves influence their mood. “The mechanisms by which tFUS affects neural activity remain unknown, as the authors acknowledge, and further research is needed.”
The authors hope the work will help scientists leverage the way brain cells shift in response to internal or external factors— known as “plasticity” in the brain.
As the study’s lead author, 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 to activate pleasure regions, but rather to modulate plasticity and encourage brain circuits to’ re-tune’ toward being more responsive’ in the moment’.”
