Coordinated Human Brainstem and Spinal Cord Networks during the Expectation of Pain Have Elements Unique from Resting-State Effects

Figures

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  Figure 1. Task paradigm for the expecting pain data. Highlighted areas indicate periods analyzed in the current study, with the blue highlighting indicating the ‘expectation’ period (after participants were told whether or not a painful stimulus would be applied) and purple highlighting indicating the ‘stimulation’ period (where participants were either experiencing a painful stimulus, or not experiencing a stimulus.

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  Figure 2. Examples of sagittal-slice functional data from an individual in the ‘resting state’ and an individual in the ‘expectation of pain’ data set for comparison. As both studies collected data with the same methods on the same scanner, the quality of the two data sets is equivalent.

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  Figure 3. Anatomical model of the regions and connections used for the structural equation modelling (SEM) analysis.

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  Figure 4. Results of ANCOVA analysis of significant β-values for the ‘expectation’ time period (upper row, after participants knew whether or not to expect pain, but before a stimulus was applied) and ‘stimulation’ time period (lower row, while participants were either experiencing pain or no stimulus). Pictured from left to right are the connections with a significant main effect of condition (‘pain’, where a stimulus would be applied, and ‘no pain’, where no stimulus would be applied), a significant main effect of individual pain sensitivity, and significant condition × sensitivity interaction effects. Significant connections are shown at a false-discovery-rate corrected pFDR < 0.05. Lines represent significant connections, circles represent the connection’s source, and the line end represents the target region. Rectangular bubbles represent anatomical regions, and the space inside the bubble is divided into the region’s different clusters. Only the C6RD segment of the spinal cord is used as being representative of brainstem-cord connectivity, because it corresponds to the heat stimulus applied to the hand.

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  Figure 5. Connections with significant differences in β-values between the ‘pain’ and ‘no pain’ conditions of the ‘predictable pain’ data, contrasted with connections with significant differences in β-values between the ‘picture’ and ‘video’ conditions of the ‘resting state’ data, by the use of paired-sample T-tests. Pictured are the comparison of connections in the ‘expectation’ period (left) and ‘stimulation’ period (right). Connections marked in dark blue represent connections with differences in β-values common to both ‘expecting pain’ and ‘resting state’ (β-values fluctuate significantly with the expectation/experience of pain but also due to resting-state fluctuations). Lines represent significant connections, the circles represent the connection’s source, and the line end represents the connection’s target region. Rectangular bubbles represent anatomical regions, and the space inside the bubble is divided into the region’s different clusters. Connections marked in light pink represent connections with differences in β-values unique to ‘expecting pain’ (β-values fluctuate significantly with the expectation/experience of pain, but not resting-state fluctuations). Significant…