Fig. 3.

Signal preprocessing for connectivity analysis. (a) Sudden amplitude changes ($>0.1\mathrm{mM}·\mathrm{mm}$; spikes) in two time-point data (0.1 s) were detected and rejected from the continuous signals (red plots). Motion artifacts also affected pre- and postspikes resulting in extremely high- or low-signal amplitudes (i.e., outlier amplitudes). (b) Time-point data with outlier amplitudes were also eliminated. (c) Seven baseline (green-colored intervals) and (d) six task (yellow-colored intervals) signals were concatenated. Gray-colored intervals indicate instruction intervals.