Researchers at the University of Arizona have published new evidence that low-intensity focused ultrasound may alter communication between major brain networks during a period of mindfulness training. The randomized study, published October 2, 2026, examined whether targeting a specific region associated with the brain’s default mode network could change neural connectivity in people who were new to meditation.
The study focused on transcranial focused ultrasound (tFUS), a noninvasive neuromodulation technique that can direct acoustic energy toward a relatively precise brain region. The researchers targeted the posterior cingulate cortex (PCC) while participants completed a two-week mindfulness program.
The findings were mixed but scientifically significant. Participants who received active ultrasound showed a greater reduction in connectivity between the default mode network (DMN) and the central executive network (CEN) than participants who received sham stimulation. However, the intervention did not produce a statistically significant difference between groups on the study’s primary overall measure of equanimity.
The research therefore does not show that ultrasound makes people better at meditation. Instead, it provides evidence that targeted neuromodulation can modify a brain-network relationship during a structured period of mindfulness training.
The Study Included 30 Meditation-Naive Adults
The research team initially planned a larger study, with a preregistered target of 80 participants. Funding, time and resource constraints changed the recruitment plan before researchers examined the outcome data. Ultimately, 30 meditation-naive adults were randomized, with 19 assigned to active tFUS and 11 assigned to sham stimulation.
Six participants did not complete the study. Four never received the intervention because of scheduling or time-related problems, while two participants discontinued because they could not keep up with the daily lessons. The final analyzed sample therefore consisted of 24 people: 16 in the active group and eight in the sham group.
The participants had no history of formal meditation training or regular contemplative practice. The analyzed group included 11 women and 13 men, with an average age of approximately 25.7 years and an age range from 18 to 53. Participants were recruited in the Tucson, Arizona, area.
The small final sample is one of the most important limitations of the study. A post hoc sensitivity analysis indicated that the study had adequate power only for relatively large effects, meaning smaller or moderate differences could easily have gone undetected.
Participants Completed Two Weeks Of Body-Focused Mindfulness
The mindfulness intervention lasted 14 consecutive days and used a standardized Body Focus training protocol.
Participants learned to pay attention to moment-to-moment physical sensations, noticing qualities such as pressure, tingling, warmth and movement. When attention wandered, they were instructed to return to bodily sensations while maintaining an accepting, non-interfering attitude.
The lessons were delivered as prerecorded audio sessions. After the first lesson at the University of Arizona’s Science Enhanced Mindful Awareness Laboratory, participants completed the remainder of the training at home.
Each day’s lesson was delivered to the participant’s phone through a text message system. Participants could repeat previous lessons, but they could not move ahead until completing the current session. Researchers also sent reminders when a lesson was missed.
The design therefore combined a relatively simple mindfulness routine with a highly controlled laboratory intervention.
This is relevant to meditation techniques because the researchers were not trying to replace mindfulness practice with technology. Instead, they were testing whether targeted brain stimulation could influence neural systems while participants were actually learning a contemplative skill.
The Ultrasound Targeted The Posterior Cingulate Cortex
The central technological component was transcranial focused ultrasound.
The researchers selected the posterior cingulate cortex, a region located near the centerline of the brain and considered an important hub within the default mode network. The DMN is associated with internally directed mental activity, including self-referential thinking, autobiographical processing and mind wandering.
The research team used participants’ MRI data to identify an individualized target corresponding to peak default mode network activity in the PCC. Neuronavigation was then used to translate that target onto each participant’s brain anatomy.
During each stimulation session, a technician held the focused-ultrasound transducer against the participant’s scalp using ultrasound transmission gel.
Participants closed their eyes and began meditating while the ultrasound was delivered for five minutes. The sham group went through the same procedure, but the ultrasound signal itself was turned off.
Afterward, participants moved to a meditation room and were allowed to continue practicing for as long as they wanted. Their voluntary meditation time was recorded.
This distinction between active and sham stimulation is critical because it gives researchers a better way to separate the effects of the ultrasound from the effects of simply participating in a meditation study.
The Brain Networks Responded Differently After Training
The strongest finding involved communication between the default mode network and the central executive network.
After the two-week intervention, the active tFUS group showed a significant reduction in DMN-CEN connectivity, while the sham group showed a smaller estimated increase that did not reach statistical significance. The condition-by-session interaction was statistically significant at p = 0.002, with an estimated coefficient of −0.118 and a 95% confidence interval from −0.186 to −0.050.
The active group’s estimated connectivity change was −0.067, while the sham group’s estimated change was +0.051 and was not statistically significant.
In practical terms, the result suggests that the brain networks became more separated in their resting-state communication after active ultrasound combined with mindfulness training.
The researchers describe this as a change in functional connectivity, rather than a simple increase or decrease in activity.
That distinction matters. Brain networks are constantly interacting, and changes in connectivity do not automatically mean that one network has become “better” or that a person has become healthier. The study provides evidence of a measurable neural change, but its psychological meaning requires further investigation.
The Study Did Not Find A Significant Improvement In Overall Equanimity
The brain finding was stronger than the behavioral result.
The researchers measured equanimity using the Equanimity Scale-16, or ES-16. The scale evaluates how people respond to pleasant, unpleasant and neutral experiences, including dimensions related to acceptance and nonreactivity.
The study’s preregistered primary equanimity outcome was the total ES-16 score.
There was no significant difference between the active and sham groups in the change in total equanimity. The total score increased by 6.63 points in the active group and 7.25 points in the sham group, but the between-group interaction was not significant, with p = 0.878.
Neither of the two ES-16 subscales showed a significant between-group difference either.
That result prevents a much stronger interpretation of the findings. The researchers cannot say that focused ultrasound made participants more equanimous than mindfulness training alone.
Instead, the clearest evidence concerns the underlying brain-network measure.
Changes In Connectivity Were Associated With Acceptance
Although the overall equanimity result was not significant, the researchers conducted an exploratory analysis examining whether changes in connectivity were related to changes in specific aspects of equanimity.
They found that greater reductions in DMN-CEN connectivity were associated with larger increases in the Acceptance component of the ES-16 across participants. The estimated relationship was statistically significant at p = 0.031.
However, this was an exploratory analysis rather than the study’s preregistered primary outcome.
That distinction is especially important because exploratory associations can generate useful hypotheses without establishing a causal pathway.
The study does not demonstrate that reducing DMN-CEN connectivity causes greater acceptance. It also does not show that acceptance caused the brain-network change.
Future research will need to determine whether this relationship survives in larger samples and under more rigorous experimental conditions.
Participants Still Had To Practice Mindfulness
One of the more interesting aspects of the research is that the ultrasound was designed as an addition to mindfulness training rather than a replacement for it.
Participants continued to meditate throughout the two-week program. During the four sessions involving tFUS or sham stimulation, participants also continued their mindfulness practice.
Average voluntary meditation time across those sessions was approximately 12.23 minutes in the active group and 9.45 minutes in the sham group. The difference of 2.78 minutes was not statistically significant, with p = 0.142.
This means the researchers did not find evidence that the ultrasound simply caused participants to meditate longer.
The technological intervention was intended to modify neural conditions during the learning process while participants continued doing the attentional work themselves.
That fits the University of Arizona team’s broader research direction. The university’s Science Enhanced Mindful Awareness Laboratory describes its work as investigating whether focused ultrasound can help people acquire meditation skills more effectively, particularly because formal mindfulness practice can be difficult for beginners.
MRI Scans Provided A Direct Look At Network Changes
The researchers used magnetic resonance imaging before and after the training period.
A 3-Tesla Siemens Skyra MRI scanner collected anatomical and functional brain images. Participants completed resting-state scans while looking at a fixation cross, followed by additional imaging after the mindfulness training. A second scan also examined brain activity while participants performed the Body Focus meditation they had learned.
The researchers also conducted susceptibility-weighted imaging to look for potential vascular changes or damage associated with the intervention. No adverse events were reported during the study.
This safety component is particularly relevant because focused ultrasound is still an emerging neuromodulation technology.
The study did report that participants sometimes heard sounds during ultrasound sessions. In the active condition, 13 of 14 participants with available sensation reports detected the ultrasound in at least one session, compared with three of eight sham participants. The reported sounds were generally described as beeping, buzzing or a high-pitched tone.
Researchers did not report adverse events related to the intervention.
The Default Mode Network Is Central To The Research Question
The University of Arizona study builds on a growing body of research examining how mindfulness interacts with the default mode network.
The DMN is often active during internally focused thought. That includes recalling personal experiences, imagining future events and constructing narratives about oneself. Those processes are useful, but excessive self-focused thinking can also contribute to repetitive thought and rumination.
The posterior cingulate cortex is one of the network’s important hubs.
Previous University of Arizona research published in 2024 used focused ultrasound to target the PCC in 30 healthy participants. That earlier experiment reported reductions in functional connectivity within the DMN and changes in subjective measures including state mindfulness and aspects of self-related experience.
The new study moves the question forward by combining the stimulation with two weeks of actual mindfulness training.
Rather than asking only what happens immediately after ultrasound stimulation, the researchers examined whether repeated pairing of stimulation and meditation was associated with changes in resting-state network connectivity after the training period.
The Study Was Smaller Than Originally Planned
The strongest limitation is sample size.
The study was initially preregistered with a target of 80 participants, but researchers ultimately randomized 30 and analyzed 24. The changes were made because of funding, time and resource constraints and occurred before the researchers examined outcome data.
The authors therefore characterize the connectivity findings as requiring replication.
Another limitation is that the study was not fully blinded. The researchers found that participants in the active condition were substantially more likely to report hearing the ultrasound than participants receiving sham stimulation. That could potentially reveal which condition a participant was receiving.
The connectivity analysis itself was also exploratory because the preregistration did not specify a unique network contrast or estimand. In addition, some of the equanimity subscale analyses were conducted after the study began rather than being part of the preregistered primary analysis.
These factors do not invalidate the results, but they make replication particularly important.
What The University Of Arizona Findings Actually Show
The October 2026 study provides evidence that focused ultrasound targeted at the posterior cingulate cortex can be paired with mindfulness training and produce measurable changes in resting-state brain-network connectivity in meditation-naive adults.
The strongest result was the reduction in connectivity between the default mode and central executive networks in the active stimulation group.
At the same time, the study did not demonstrate a significant improvement in overall equanimity compared with sham stimulation. The sample was small, the study was not fully blinded, and several analyses were exploratory.
That makes the research more useful as a mechanistic study than as evidence for a new mindfulness treatment.
The next step is a larger, fully blinded experiment that can determine whether the neural effect can be reliably reproduced and whether it eventually translates into measurable improvements in meditation skills, psychological well-being or clinical outcomes.
For mindfulness research, the larger question is intriguing: if specific brain networks influence how easily people sustain attention and respond to internal experiences, could noninvasive neuromodulation eventually help beginners develop those skills more efficiently?
The University of Arizona study does not answer that question yet. It does, however, provide a controlled demonstration that brain-network modulation and mindfulness training can be studied together, creating a path for future research into how meditation skills develop in the brain.