Research shows ultrasound technology can be used to promote mindfulness

One of the fascinating abilities of the human mind is daydreaming, where the mind wanders into spontaneous thoughts, fantasies and scenarios, often without conscious effort, allowing creativity and reflection to flow freely.

In a new study published in Frontiers in human neuroscienceResearchers at the University of Arizona used low-intensity ultrasound technology to noninvasively alter a region of the brain associated with activities such as daydreaming, recalling memories and visualizing the future. They found that the technique could ultimately improve mindfulness, marking a major advance in the field of neuroscience.

The researchers used a low-intensity ultrasound technique called transcranial focused ultrasound (TFUS) to alter the brain’s default mode network, a system of interconnected brain regions that are particularly active during activities such as daydreaming.

“We are the first to show that the default mode network can be directly controlled and modulated noninvasively,” said lead investigator Brian Lord, a postdoctoral researcher in the University of Alabama’s Department of Psychology.

One region of the default mode network, the posterior cingulate cortex, has been implicated as a key player in how the mind records experiences, said Lord, who is part of the Science Enhanced Mindfulness (SEMA) Lab at the university’s Center for Consciousness Studies. The default mode network is active when people are engaged in introspection or letting their minds wander, perhaps by settling into a story, reminiscing about the past or planning future scenarios.

“That’s how we form stories about ourselves,” Lord said.

While this storytelling is natural and important for developing a coherent sense of self, it can also prevent people from being present in the moment, Lord said. For example, when someone tries to meditate, it can lead to rumination and negative thinking.

To improve mindfulness and help people live more in the moment, Lord’s team used TFUS, a tool that can stimulate specific brain areas noninvasively and with millimeter precision.

Unlike other noninvasive brain stimulation methods, such as transcranial electrical stimulation and transcranial magnetic stimulation, TFUS can penetrate below the cortex, the outermost layer of the brain. As little as five minutes of stimulation can produce meaningful effects.

The experiment involved 30 participants who received TFUS in the posterior cingulate cortex of the brain’s default mode network. Researchers used functional magnetic resonance imaging, or fMRI, to observe changes in brain activity. Participants were asked to report their feelings and experiences before and after the TFUS treatment.

The study found that TFUS reduced brain connectivity within the default network and affected participants’ mindfulness and subjective experiences, such as their sense of self and time perception.

“The best thing is that you use a minimal amount of energy to change brain activity. You just give the brain a gentle nudge with low-intensity ultrasound,” Lord said.

The ability to target and alter brain networks opens up the possibility of using TFUS for precision therapies, which are medical treatments that are specifically tailored to an individual’s unique characteristics, such as their genetic makeup, lifestyle and environment. TFUS could also potentially be used to treat mood disorders such as depression and anxiety, a possibility that other research groups are now exploring, Lord said.

“Unlike neuroimaging techniques where you can only make correlations with brain activity, noninvasive stimulation tools like TFUS allow you to probe the brain and develop causal models,” Lord said. “That’s a really powerful thing for the entire field of neuroscience.”