fMRI Evaluation of Auricular Acupuncture Targets: An Exploratory Clinical Study

Data collection is divided into two stages:

Baseline : Collection of demographic data, baseline fMRI scan, and clinical assessment(T0).

post-intervention : fMRI scan and clinical assessment immediately after the intervention(T1).

The functional connectivity between the bilateral insula and medial prefrontal cortex was quantified by calculating the Pearson correlation of their mean time series at baseline and post-intervention. This connectivity strength serves as a proxy for the efficiency of information exchange between the interoceptive hub and the self-referential/emotion-regulatory hub. An increase following auricular acupuncture may reflect enhanced psychosomatic integration and top-down emotional regulation, suggesting a functional optimization of this circuit. Conversely, a decrease could indicate a disruption of pathological hyper-connectivity related to emotional constraint or an upregulation of control-mechanisms consistent with the observed alleviation of emotional symptoms

Regional homogeneity (ReHo) was calculated as Kendall's coefficient of concordance between each voxel and its 26 nearest neighbors, assessed separately before and after the intervention. This metric captures the temporal synchrony of neural activity within local brain regions. Following auricular acupuncture, increased ReHo in regions such as the insula and prefrontal cortex may reflect improved neural coordination and functional integration. Conversely, decreased ReHo in specific areas could indicate a modulatory effect on abnormally elevated local synchrony.

Amplitude of low-frequency fluctuation (ALFF) was quantified by calculating the square root of the power spectrum within the 0.01-0.08 Hz frequency band of the BOLD signal, followed by normalization to the global mean ALFF value. This metric reflects the intensity of spontaneous neural activity in the brain. An increase in ALFF within emotion- and cognition-related regions following auricular acupuncture may indicate an elevation in baseline neural activity or metabolic activity in these areas. Conversely, a decrease in ALFF in regions such as the limbic system could reflect an inhibitory modulatory effect of the intervention on hyperactivity, potentially contributing to emotional stabilization.

Fractional amplitude of low-frequency fluctuation (fALFF) was quantified by calculating the ratio of low-frequency ALFF to the full-frequency ALFF before and after the intervention, followed by normalization to the global mean fALFF value. Changes in fALFF following the intervention allow a more specific assessment of auricular acupuncture's regulatory effects on intrinsic neural oscillations related to cognition and emotion. When interpreted in conjunction with ALFF changes, the direction of fALFF alteration can help elucidate the specific mechanisms through which auricular acupuncture modulates neural activity patterns.

Voxel-Mirrored Homotopic Connectivity (VMHC) was assessed by calculating the Pearson correlation coefficient between BOLD time series from symmetrically corresponding voxel pairs in the left and right hemispheres, separately before and after the intervention. The VMHC value quantifies the functional coordination between homotopic regions across the two cerebral hemispheres. Following auricular acupuncture, enhanced VMHC in regions associated with emotional regulation and cognitive control, such as the prefrontal cortex and anterior cingulate cortex, may suggest improved interhemispheric balance and integration of emotional processing. Conversely, changes in VMHC within specific regions could help clarify how the intervention modulates functional imbalances between hemispheres, particularly those related to constrained emotional states.