Demographic data and preliminary analyses
No participants opted to exclude any or all of their questionnaire or performance data from the current analyses. The groups did not differ in demographic characteristics (ps > .20; see Table 2). On average, both groups underestimated their body-image size during the body distortion task and the level of underestimation did not differ between groups (MLC = −11.12%; MTR = −9.92%), t(78) = 0.88, p = 0.38, d = 0.20.
Table 2. Participant demographic characteristics
The Mann–Whitney–Wilcoxon U test on clothing comfort indicated that the LC group perceived their clothing to be significantly more comfortable than the TR group (MLC = 4; MTR = 3.38; U = 569, p = .02, r = .26). No significant differences were found between the groups in their awareness of their clothing (MLC = 2.53; MTR = 2.63; U = 834, p = .78, r = .04) or the similarity of the clothing to their regular clothing (MLC = 2.43; MTR = 2.08; U = 625, p = .14, r = .17).
Main analysis: Motor performance during experimental trials
The analyses of the goal and the spatial measures of performance did not reveal any statistically significant effects for Group, Block, or Group × Block interactions (ps ≥ 0.10; see Table 3 in the Appendix). Overall, these analyses suggest that the clothing worn by the participants did not impact the spatial characteristics of the movements or the resulting accumulation in points.
The temporal measures of performance included mean RT and MT as well as the variability of RT and MT. For mean RT, there were no significant main effects of Group, F(1, 78) = 0.88, p = .35, ηp2 = 0.01, or Block, F(1, 78) = 1.73, p = .19, ηp2 < 0.01. The interaction between Group and Block was also not statistically significant, F(1, 78) = 0.5, p = .48, ηp2 < 0.01. For RT standard deviation, there was a significant effect of Block, whereby participants demonstrated higher variability during Block 2 (M = 49.4 ms, SD = 16) relative to Block 1 (M = 42.1 ms, SD = 13), F(1, 78) = 19.85, p < .01, ηp2 = 0.06. The main effect of Group, F(1, 78) = 1.25, p = 0.27, ηp2 = 0.01, and the interaction between Group and Block, F(1, 78) = 0.06, p = 0.81, ηp2 < 0.01, were not statistically significant in RT variability. Thus, the processes leading to response initiation did not differ between clothing groups.
The analysis of mean MT revealed a significant main effect of Block, in which participants demonstrated decreased mean MT from Block 1 (M = 406 ms, SD = 51) to Block 2 (M = 395 ms, SD = 52), F(1, 78) = 8.87, p < .01, ηp2 = 0.10. Although there was no significant main effect of Group, F(1, 78) = 2.77, p = 0.1, ηp2 = 0.03, there was a significant interaction between Group and Block for mean MT, F(1, 78) = 6.35, p = .01, ηp2 = 0.075 (see Fig. 3a). Post hoc analysis of the interaction using Tukey’s HSD (p < .05, critical value = 13.8 ms) indicated that the LC group decreased their MTs from Block 1 to Block 2, whereas the TR group did not. Further, while MTs for the LC group were not different from those of the TR group in Block 1, mean MTs for the LC group were statistically lower than those for the TR group in Block 2. Analysis of MT standard deviation revealed that the variability of MT differed significantly between groups, with the TR group (M = 37.64 ms, SD = 8.65) demonstrating higher variability than the LC clothing group (M = 33.10 ms, SD = 10.27)—main effect for Group, F(1, 78) = 7.62, p = .01, ηp2 = 0.07 (see Fig. 3b). A main effect of Block was also found, whereby participants demonstrated a decrease in MT standard deviation from Block 1 (M = 36.6 ms, SD = 11) to Block 2 (M = 34.1 ms, SD = 11), F(1, 78) = 3.98, p = .05, ηp2 = 0.01. No significant interaction between Group and Block was found, F(1, 78) = 0.02, p = .89, ηp2 < 0.01 (see Fig. 3b). See Table 4 in the Appendix for descriptive statistics for measures of motor performance. Overall, the results of this analysis revealed that the participants wearing the tight and revealing clothing executed their movements with greater variability than the group wearing the loose and concealing clothing. Further, the LC group positively adapted their movement times (executed more efficient movements) with experience, whereas the TR group did not.
Relation between clothing comfort and motor performance
Recall that, although there was no between-group difference in perceived body size on the body distortion task, there was a significant effect of Group on perceived clothing comfort as well as a significant effect of Group in MT standard deviation and a significant interaction effect of Group and Block on mean MT during experimental blocks. To determine if there was a significant association between perceived clothing comfort and these measures of performance, separate correlations were conducted between perceived comfort and mean MT and MT standard deviation. Perceived clothing comfort did not predict mean MT, F(2, 157) = 1.47, r2 = .01, p = .23, nor MT standard deviation, F(2, 157) = 2.73, r2 = .02, p = .07.