3.2 Main effect of stroking and sex differences
Across the whole group (N = 18), gentle skin stroking evoked neural activation in bilateral somatosensory, bilateral insular, middle cingulate and precuneus cortices and bilateral cerebellar vermis as compared to conditions without stimulus (Figure 1). Our results expectedly resemble brain activation maps reported previously by Tuulari et al (Tuulari et al., 2019c), highlighting the activation of the two brain regions known to be the main targets of CT-fibers. Moreover, similar activity patterns resulted considering the smaller sample (N = 13) (Figure S1).
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Regarding sex differences, compared to males (N = 10), females (N= 8) exhibited stronger BOLD increases in the bilateral OFC, right ventral and bilateral inferior striatum, pons, and cerebellum, at a statistical threshold of p = 0.01, FDR-corrected at the cluster level (Figure 2a). Including to the model maternal BMI, depressive and anxiety scores did not change the results at uncorrected p < 0.05. Figure S2 represents differences between males and females in the smaller sample (N = 13).
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