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Sijia Guo1,2 ,* Jing Lu,1– 3,* Yufang Wang,2 Yuqin Li,2 Binxin Huang,2 Yuxin Zhang,2 Wenhui Gong,2 Dezhong Yao,1– 3 Yin Yuan,1 Yang Xia1– 3 1The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, University of Electronic Science and Technology of China, Chengdu, People’s Republic of China; 2Center for Information in BioMedicine, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, People’s Republic of China; 3Research Unit of NeuroInformation, Chinese Academy of Medical Sciences, 2019RU035, Chengdu, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yin Yuan; Yang Xia Email 1140587540@qq.com; xiayang@uestc.edu.cnBackground: Music has shown positive effects on pain management in previous studies. However, the relationship between musical emotional types and therapeutic effects remains unclear. To investigate this issue, this study tested three typical emotional types of music and discussed their neural mechanisms in relation to pain modulation.Subjects and Methods: In this experiment, 40 participants were exposed to cold pain under four conditions: listening to happy music, listening to neutral music, listening to sad music and no sound. EEG and pain thresholds were recorded. The participants were divided into the remission group and the nonremission group for analysis. Differences among conditions were quantified by the duration of exposure to the pain-inducing stimulus in the remission group. EEG data were obtained using a fast Fourier transform (FFT) and then correlated with the behavioral data.Results: We found that sad music had a significantly better effect on alleviating pain, as a result of brain oscillations in a higher beta band and the gamma band at the O2 and P4 electrodes. The comparison between the remission group and the nonremission group suggested that personality may affect music-induced analgesia, and dominance, liveliness and introvert and extrovert personality traits were associated with pain modulation by sad music. Additionally, in the network analysis, we compared brain networks under the three conditions and discussed the possible mechanisms underlying the better analgesic effect of sad music.Conclusion: Sad music may have a better effect on alleviating pain, and its neural mechanisms are also discussed. This work may help understand the effects of music on pain modulation, which also has potential value for clinical use.Keywords: pain, music-induced analgesia, personality, EEG, brain network

For silicon carbide (SiC) processed by ion-implantation, dedicated test structure fabrication or destructive sample processing on test wafers are usually required to obtain depth profiles of electrical characteristics such as carrier concentration. In this study, a rapid and non-destructive approach for depth profiling is presented that uses confocal Raman microscopy. As an example, a 4H-SiC substrate with an epitaxial layer of several micrometers thick and top layer in nanoscale that was modified by ion-implantation was characterized. From the Raman depth profiling, longitudinal optical (LO) mode from the epitaxial layer and longitudinal optical phonon-plasmon coupled (LOPC) mode from the substrate layer can be sensitively distinguished at the interface. The position profile of the LOPC peak intensity in the depth direction was found to be effective in estimating the thickness of the epitaxial layer. For three kinds of epitaxial layer with thicknesses of 5.3 mm, 6 mm, and 7.5 mm, the average deviations of the Raman depth analysis were −1.7 mm, −1.2 mm, and −1.4 mm, respectively. Moreover, when moving the focal plane from the heavily doped sample (~1018 cm−3) to the epitaxial layer (~1016 cm−3), the LOPC peak showed a blue shift. The twice travel of the photon (excitation and collection) through the ion-implanted layer with doping concentrations higher than 1 × 1018 cm−3 led to a difference in the LOPC peak position for samples with the same epitaxial layer and substrate layer. Furthermore, the influences of the setup in terms of pinhole size and numerical aperture of objective lens on the depth profiling results were studied. Different from other research on Raman depth profiling, the 50× long working distance objective lens (50L× lens) was found more suitable than the 100× lens for the depth analysis 4H-SiC with a multi-layer structure.