Finally, the interaction group by delay approached significance, indicating that PWS increased their tapping variability more prominently as the delay increased (ꭓ 2 (1) = 29.09, p < 0.001), compared to the control group (ꭓ 2 (1) = 18.09, p < 0.001).
Moreover, in the continuation phase, the main effect of the group was marginally significant, indicating an overall greater variability for PWS (M = 0.31) compared to PNS (M = 0.22).
Although not reaching statistical significance, under sound instruction, PWS showed a trend towards greater tapping variability, consistent with a substantial body of evidence [ 8 , 29 , 30 , 31 , 32 , 34 , 35 , 41 , 42 ].