Journal: bioRxiv

Article Title: Low-intensity focused ultrasound to the human insular cortex differentially modulates the heartbeat-evoked potential: a proof-of-concept study

doi: 10.1101/2024.03.08.584152

Figure Lengend Snippet: A. Graphical depiction of formal testing days. Participants (N = 16) completed four arms randomly assigned on four separate days: Low-intensity focused ultrasound (LIFU) to the anterior insula (AI), posterior insula (PI), dorsal anterior cingulate cortex (dACC) or Sham. Black dots on brains represent approximate locations of each target for the AI (left dorsal anterior short gyrus), PI (left dorsal posterior long gyrus), and dACC (Montreal Neurologic Institute (MNI) coordinates [0,18,30]) for all participants. Graphical brains were adapted from Biorender.com. B. For each session, data was collected over a 10 minute time window while participants sat at rest during continuous electroencephalogram (EEG) and electrocardiogram (ECG) recording. For each active day, a total of 100 LIFU stimulations were delivered over the 10-minute time window with a fixed interstimulus interval (ISI) of 5 seconds. Continuous auditory masking was delivered over the entire time window for all conditions. Blow-up of a single orange bar details the LIFU stimulation parameters. One second of LIFU was delivered with a fundamental frequency of 500 kHz, a pulse repetition frequency (PRF) of 1 kHz, a duty cycle (DC) of 36%, and a total burst duration (BD) of 1 second.

Article Snippet: Two ECG electrodes (MedGel TM , MDSM611903) were placed on the anterior surface of both forearms immediately distal to the antecubital fossa (Einthoven lead I configuration) sampled at 1 kHz using a physiologic data acquisition box (Physio16, Magstim EGI, OR, USA) that has an integrated ground (GES 400, Magstim EGI, Eguene, OR, USA).

Techniques:

Journal: bioRxiv

Article Title: Low-intensity focused ultrasound to the human insular cortex differentially modulates the heartbeat-evoked potential: a proof-of-concept study

doi: 10.1101/2024.03.08.584152

Figure Lengend Snippet: A. Results from the permutation analysis across time for the HEP data in . X-axis is time (ms), left y-axis and black line represents p-values, right y-axis and orange line represents F-statistics from one-way ANOVA. Horizontal dashed red line represents p = 0.05. B. Results from the permutation analysis across time for ECG data in . X-axis is time (ms), left y-axis and black line represents p-values, right y-axis and orange line represents F-statistics. Horizontal dashed red line represents p = 0.05.

Article Snippet: Two ECG electrodes (MedGel TM , MDSM611903) were placed on the anterior surface of both forearms immediately distal to the antecubital fossa (Einthoven lead I configuration) sampled at 1 kHz using a physiologic data acquisition box (Physio16, Magstim EGI, OR, USA) that has an integrated ground (GES 400, Magstim EGI, Eguene, OR, USA).

Techniques:

Journal: bioRxiv

Article Title: Low-intensity focused ultrasound to the human insular cortex differentially modulates the heartbeat-evoked potential: a proof-of-concept study

doi: 10.1101/2024.03.08.584152

Figure Lengend Snippet: A. Group (N=16) mean ± SEM electrocardiogram (ECG) amplitudes across time. X-axis is time in milliseconds (ms) and y-axis is amplitude in microvolts (μV). Grey background represents the equivalent period of the cardiac field artifact from EEG data while the white represents the equivalent heartbeat-evoked potential (HEP) time window of interest. F-statistics and p-values from permutation testing can be seen in . B. (Left) Linear regression comparing the average change in the HEP amplitude to the average change in the electrocardiogram (ECG) amplitude, both across the first significant HEP time window for posterior insula (PI) relative to Sham. X-axis is the change (PI-Sham) in the ECG amplitude (μV) and y-axis is the change (PI-Sham) in the HEP amplitude (μV). Solid red line is the fitted regression line and the dotted lines represent the 95% confidence bounds. P = p-value. (Right) Linear regression comparing the average change in HEP and ECG amplitudes across the second significant HEP time window for PI relative to dorsal anterior cingulate (dACC) conditions. C. (Left) Linear regression comparing the average change in the HEP amplitude across the first significant HEP time window to the average change in amplitude across the significant cardiac field artifact (CFA) window for PI relative to Sham conditions. X-axis is the change (PI-Sham) in the CFA amplitude (μV) and y-axis is the change (PI-Sham) in the HEP amplitude (μV). Solid red line is the fitted regression line and the dotted lines represent the 95% confidence interval. P = p-value. (Right) Linear regression comparing the average change in HEP amplitudes across the second significant HEP time window and to the average change in amplitude across the significant CFA time period for PI relative to dACC conditions.

Article Snippet: Two ECG electrodes (MedGel TM , MDSM611903) were placed on the anterior surface of both forearms immediately distal to the antecubital fossa (Einthoven lead I configuration) sampled at 1 kHz using a physiologic data acquisition box (Physio16, Magstim EGI, OR, USA) that has an integrated ground (GES 400, Magstim EGI, Eguene, OR, USA).

Techniques: