Brain–body interactions associated with the transition from mind wandering to awareness of its occurrence

Figures

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  Figure 1. Experimental settings and behavioral results. (A) and (B) Overview of the experimental design: In the breathing-focused condition, the participants responded at the end of exhalation, and in the sound-focused condition, they responded to each sound. During the response task, participants reported when they became aware of MW and answered questions about the content of their thoughts (emotional valence and time orientation) before resuming the task. Sound stimuli were consistently presented in both conditions. Each task was performed for four 12-min sessions. (C) Measurement indices and definitions of attentional states: We recorded EEG (65 channels), ECG (1 channel), and respiration (2 channels) data during the task. The interval spanning from 1 to 5 s before the MW report was used to define the aware state, whereas the period spanning from 5 to 9 s before the MW was reported was defined as the MW state. The focus state was defined as the 4 s after the initial sound stimulus after the task was resumed. (D) MW frequency per task condition: The horizontal axis shows the task condition, and the vertical axis shows the average number of MW reports. Each dot represents the data for…

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  Figure 2. Changes in time–frequency components related to the transition to awareness of MW. (A) Difference in spectral power between the MW and focus states: We show the statistical value of the difference between the frequency of each electrode in the MW and focus states. The vertical axis shows the electrode number, and the horizontal axis shows the frequency band. Warmer colors indicate greater intensity in certain frequency bands during MW, whereas cooler colors indicate greater intensity in the focus state. The dotted lines mark the areas that reflected the significant difference. (B) Difference in spectral power between the MW and aware states: Same as in (A), except for the state being compared. Warmer and cooler colors indicate increased intensity in the MW and aware states, respectively. (C) Time series of the spectrum power before MW is reported: The horizontal axis represents the time in seconds from when MW is reported, and the vertical axis represents the spectral power values. The bold line represents the mean value, and the range represents the standard error. The vertical dotted line represents the 95% credible interval (CI) of the estimated change point. The interval…

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  Figure 3. Cardiac activity and its central process in each task condition and attentional state. (A) Cardiac activity in each task condition and attentional state: The horizontal axis shows the attentional state, the vertical axis shows the RR interval, and the color indicates the task condition. Each dot indicates a participant. (B)–(E) Modulation of HEP by attentional state and task condition: Grand average HEP waveforms for the two compared conditions, averaged across all channels contributing to the significant effect identified by the cluster-based permutation test. The vertical axis shows the amplitudes, and the horizontal axis shows the time from the R peak. The bold line indicates the mean amplitude, and the shaded range represents the standard error. The gray area on the time axis highlights the significant difference in the time window. We also displayed the topography map of the difference in voltage between the two conditions, which was calculated by subtracting the condition listed second in the legend from that listed first (e.g. for B, focus—MW), averaged across the corresponding time window. All electrode positions are indicated by white circles, whereas electrodes…

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  Figure 4. Changes in respiration and the accompanying RR interval and its central process before MW was reported. (A) Number of respiratory cycles during the task: The task condition is shown on the horizontal axis, and the number of cycles is shown on the vertical axis. Each dot represents a participant. (B) Percentage of the inhalation phase each second before MW was reported: Inhalation rates are shown on the vertical axis, with the time in seconds (s) from when MW was reported shown on the horizontal axis. The horizontal dotted lines indicate the baseline inhalation rate calculated via random sampling from the entire dataset for each condition. The error bars indicate the standard errors. (C) RR interval at each second before MW was reported: The RR interval is shown on the vertical axis, with the time in seconds from the reports of MW on the horizontal axis. The error bars indicate the standard errors. (D) Modulation of HEP waveforms during the exhalation phase: This panel compares the HEP recorded during the exhalation phase in the BF conditions to those in the SF condition. The figure format is identical to that used in Fig. 3. *P < .05, **P < .01, ***P < .001.