Fig. 2: Parieto-occipital event-related potential (ERP) indicators of gut sensation during vibratory gut stimulation and their association with perceptual accuracy measures during normal and enhanced stimulation in n = 40 biologically independent samples.

a The average ERP waveforms during the normal (blue) and enhanced (green) blocks for channels (Cz, CP1, CP2, Pz, POz, O1, Oz, and O2) showing the most consistent responses in the cluster-based permutation analysis. Intensity-dependent differences were identified during a late (i.e., 400–720 ms) window (marked with a horizontal black bar). Shaded areas represent the standard error of the mean for the ERP signal at each time point. Time-zero represents the earliest onset of vibratory stimulation corresponding to correctly detected vibrations, as indicated by participant button presses. The presented waveforms were calculated from the average mastoid-referenced EEG. b Scalp topography during the late window after the vibration onset relative to the pre-stimulus baseline for the normal and enhanced conditions. c The positive association between the late ERP signal strength (averaged signal among Cz, CP1, CP2, Pz, POz, O1, Oz, and O2 channels) and perceptual accuracy (normalized A prime) was significant after controlling for the condition (Spearman correlation: ρ = 0.354, p < 0.001). Average ERP amplitude data from one participant was excluded for being detected as an outlier for the enhanced condition. d The positive association between late ERP latency (averaged signal among Cz, CP1, CP2, Pz, POz, O1, Oz, and O2 channels) and response latency was significant after controlling for the condition (Spearman correlation: ρ = 0.341, p = 0.002). The regression lines indicate linear fits, and shaded areas correspond to the 95% confidence interval for the regressions. Source data are provided as a Source Data file.