Transcranial Focused Ultrasound Alters Conflict and Emotional Processing, Physiology, and Performance I: Dorsal Anterior Cingulate Cortex Targeting

The dorsal anterior cingulate cortex (dACC) operates as an integrator of bottom-up and top-down signals and is implicated in both cognitive control and emotional processing. The dACC is believed to be causally involved in switching between attention networks, and previous work has linked it to cognitive performance, concentration, relaxation, and emotional distraction. The present study was designed to evaluate the feasibility of influencing default mode network (DMN) activity and emotional attention by targeting and modulating the dACC with transcranial focused ultrasound (tFUS). Subjects were divided into two groups, one receiving MR-neuronavigated tFUS to the dACC and the other an identical, but inactive tFUS sham. Subjects performed a modified version of the Erikson flanker paradigm using fear and neutral faces as emotional background distractors. Our observations demonstrate that tFUS can be targeted to the human dACC to produce effects consistent with those expected from relaxed contention, including significantly reduced reaction time slowing due to emotional distractors, and an increase in parasympathetic markers of the HRV. These results suggest that tFUS altered emotional processing and enhanced sustained attention, perhaps by facilitating reduced attentional engagement with emotional distractors and reduced need for attention switching evidenced by significant effects on event related potentials (ERPs), reduced alpha suppression, and modulation of delta and theta EEG activity. We conclude that the dACC represents a viable neuroanatomical target for tFUS in order to modulate DMN activity, including emotional attention, conflict resolution, and cognitive control. These effects of dACC-targeted tFUS may prove useful for treating certain mental health disorders known to involve perturbed DMN activity, such as depression and anxiety. ### Competing Interest Statement WJT is an equity holding member of IST, LLC a commercially active neurotechnology company. WJT is also the inventor on USA and international issued and pending patents related to the methods and devices used in this study for the modulation of brain activity by focused ultrasound. ### Clinical Trial The study was an academic sponsored exploratory research study and was not registered on clinicaltrials.gov. There were no therapeutic outcomes measured. ### Funding Statement Funding was provided by start-up funds from Arizona State University and strategic funds provided by the Arizona WearTech Applied Research Center. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: All procedures were performed using protocols approved by the Arizona State University Institutional Review Board. All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.