Chapter 6 – EEG imaging 205 Pre- to post-acquisition changes in LRTC are negatively associated with the magnitude of induced nocebo hyperalgesia We asked whether differences in EEG due to nocebo conditioning were associated with magnitude of nocebo hyperalgesia (Fig. 2). Our primary hypothesis was that pre- to post-acquisition differences in the alpha band would be associated with magnitudes of induced nocebo hyperalgesia. There was no significant association between change in resting-state alpha power from pre- to post-acquisition and magnitude of nocebo hyperalgesia (mean across electrodes, rs = -0.04, p = 0.85). We then looked more broadly at spectral and temporal biomarkers in alpha, beta and gamma bands to test for associations with the magnitude of nocebo hyperalgesia. Long-range temporal correlations were negatively associated with induced nocebo hyperalgesia for beta band for one lead (Electrode PO4, rs = -0.43, p = 0.02) (Fig. 2b), but not for alpha and gamma bands (Fig. 2a, c). LRTC of neuronal oscillations during rest predict pain response to nocebo treatment We then asked whether resting-state EEG parameters can predict magnitude of nocebo hyperalgesia. There was no association between DFA and magnitude of nocebo hyperalgesia within the alpha band (rs = 0.25, p = 0.18; Fig. 2d). Nocebo hyperalgesia was significantly positively correlated with DFA of beta (rs = 0.51, p = 0.003) (Fig. 2e) and gamma band (rs = 0.47, p = 0.008) (Fig. 2f). These results show that individuals with strong LRTC during rest have a larger nocebo effect than individuals with weak LRTC. Since stronger LRTC reflect more complex neural dynamics, these findings indicate that people with more complex brain activity are more susceptible to the acquisition of nocebo.
RkJQdWJsaXNoZXIy MTk4NDMw