Fig. 4

Time-frequency plots. A Wavelet Transform Coherence (WTC) spectrum of HbO signals from channel 20 of the experimental group. stronger synchrony, coded in red, is in the task frequency band (0.010–0.019 Hz). B Paired t test plot for task vs. rest across 0.01–0.1 Hz. It shows stronger INS during tasks than rest at 0.010–0.017 Hz, covering the decision-making duration.