Fig 6. Average changes in oxy-Hb (×10⁻³) in channel 18, 19, and 20 during the two periods in the two conditions (n = 20).

During the baseline period (40 s), the participant is listening to Japanese vowels repeatedly in each condition. During the listening period (60 s), the participant is listening to a letter of gratitude in the experimental condition, or a conversation about the weather in the control condition. Error bars represent standard error.