The Impact of Unpredictability on Dyspnea Perception, Anxiety and Interoceptive Error Processing

Figures

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  FIGURE 1. Graphical visualization of the experimental design. In both predictable and unpredictable conditions, the participants performed the respiratory forced choice reaction time task during which they received 50 inspiratory occlusions of two different durations. They indicated via mouse press whether each occlusion was short (160 ms) or long (240 ms), respectively, directly after each occlusion. In the predictable condition, tones were presented every minute and immediately followed by 2 loaded inspirations during which participants inspired through a resistive load (40 cmH2O/L/s). In the unpredictable condition, tones were presented every minute, but the 2 loaded inspirations were presented randomly and not related to the tones. The conditions were announced on the screen right before the blocks started and an additional specific color frame remained on the screen for the whole duration of the block to remind the participants of the condition. The order of the predictable and unpredictable conditions was counterbalanced across participants.

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  FIGURE 2. (A) Ratings of dyspnea intensity and dyspnea unpleasantness for the predictable and unpredictable condition on a visual analog scale (0–100); (B) ratings of affective state including valence, arousal and anxiety for the predictable and unpredictable condition on a scale ranging from 1 to 6; (C) ratings of anxiety separately for the condition orders unpredictable- predictable-unpredictable-predictable (UPUP) and predictable-unpredictable-predictable-unpredictable (PUPU) on a scale ranging from 1 to 6. Error bars represent standard errors. ∗p < 0.05.

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  FIGURE 3. Average waveforms and respective scalp topography plots around FCz for the startle probe N100 for the predictable and unpredictable condition for the (A) condition order unpredictable- predictable-unpredictable-predictable (UPUP) and (B) condition order predictable-unpredictable-predictable- unpredictable (PUPU).

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  FIGURE 4. Representative difference waveforms for the interoceptive ERN (error response minus correct response) and respective scalp topography plots around FCz for the predictable and unpredictable condition for (A) participant undergoing the condition order unpredictable- predictable-unpredictable-predictable (UPUP) and (B) participant undergoing the condition order predictable-unpredictable-predictable-unpredictable (PUPU); (C) means of difference waveforms for the interoceptive ERN around FCz across all participants undergoing the condition order UPUP and all participants undergoing condition order PUPU. Error bars represent standard errors. ∗p < 0.05.

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  FIGURE 5. Correlations between (A) anxiety sensitivity (ASI scores) and ratings of dyspnea unpleasantness during the predictable and unpredictable conditions and (B) anxiety sensitivity (ASI scores) and ratings of anxiety during the predictable and unpredictable conditions. ∗p < 0.006.