mirror reflection (statements 3-7, 11-12). The second principal component “Syn-C2” included statements relating to feelings of a causal relationship between the touch of the cotton bud in the movie and on one’s own face, of being in control of the other person’s face or one’s face being out of one’s control, of one’s face being less vivid than normal and that one was imitating or being imitated by the other person (statements 1-2, 8-10, 15-17). Finally, the third principal component “Syn-C3” included statements that related to the feelings of the other person being attractive and trustworthy (statements 13-14). In the asynchronous condition, analysis of eigenvalues and the scree plot led to the extraction of five components which together accounted for 64.5% of the variance in the data (see Table 2). The first principal component “Asyn-C1” accounted for a large proportion of the variance (35%), and included statements relating to feelings of a causal relationship between the touch of the cotton bud in the movie and one’s own face, of the other person’s face being one’s own face, of owning and being in control of the other person’s face, and of looking at one’s own mirror reflection (statements 1-5, 8). The second principal component “Asyn-C2” included four statements that related to the feelings of the other person’s face beginning to resemble and being similar to one’s own face, as well as feelings of one’s face beginning to resemble and being similar to the other person’s face (statements 6-7, 11-12). The third principal component “Asyn-C3” included statements that related to feelings of being imitated by the other person, of one’s blinks being synchronous with the other person’s blinks, and of affiliation with the other person (statements 16-18). The fourth principal component “Asyn-C4” included two statements that related to the feelings of the other person being attractive and trustworthy (statements 13-14). Finally, the fifth principal component “Asyn-C5”
scores of the items that loaded in each component. These component scores, then, quantify the experience of the participants for each of the dimensions in the same Likert scale that participants used to give their ratings for each individual statement (summated scales; Hair, Black, Babin, Anderson & Tatham, 2006). They can be used for direct comparison between synchronous and asynchronous conditions since they reflect an experience common to both conditions. The component scores were submitted in a mixed ANOVA with factors condition (synchronous vs. asynchronous) and component “similarity” or “affect”), and between-subjects factors gender and the order of presentation (i.e., whether the synchronous or the asynchronous condition was first presented). The main effects of condition (F(1, 252) = 76.2, p < .0001, p2 = .23) and component (F(2, 504) = 193.8, p < .0001, p2 = .43) were significant, as well as their 2-way interaction (F(2, 504) = 13.2, p < .0001, p2 = .05). The significant effect of ‘condition’ indicates that, overall, participants agreed more with the statements after synchronous (M ± SE = 3.54 ± .07) than after asynchronous stimulation (M ± SE = 2.99 ± .05). The significant effect of ‘component’ indicates that, overall, participants agreed more with the statements comprising the component “affect” (M ± SE = 4.00 ± .06) than with those comprising the components (M ± SE = 2.64 ± .06) and “similarity” (M ± SE = 3.16 ± .07), independent of the pattern of stimulation. The significant interaction (see Figure 2) was driven by a greater difference between the synchronous and asynchronous conditions for the ratings for the statements comprising the component scores and “similarity” than for those comprising the component score “affect”. To investigate this interaction, we calculated the difference “synchronous minus asynchronous” for each component score. The resulting values reflect the magnitude
the significant interaction was driven by a greater difference between the synchronous and asynchronous conditions for the ratings for the statements comprising the component scores “self-identification” (mean difference ± SE = 1.03 ± .14; t(55) = 7.5, p < .0001) and “similarity” (mean difference ± SE =.85 ± .15; t(55) = 5.5, p < .0001) than for those comprising the component score “affect” (mean difference ± SE = .35 ± .14; t(55) = 2.5, p = .014). Follow-up paired samples t-tests between the calculated difference “synchronous minus asynchronous” for all component scores revealed a significant difference between the score “affect” and the scores “self-identification” (t(55) = 3.8, p < .0001) and “similarity” (t(49) = 2.7, p = .009). These findings replicate the main results of Experiment 1. Furthermore, the interaction of condition with the IS group was significant (F(1, 54) = 4.11, p < .05, p2 = .07), because as shown in Figure 4, participants with low IS gave overall higher ratings to all three components following synchronous stimulation (M ± SE = 4.19 ± .14) than participants with high IS (M ± SE = 3.81 ± .14), while for both groups ratings following asynchronous stimulation were comparable (for low IS, M ± SE = 3.23 ± .16; for high IS, M ± SE = 3.28 ± .16). Figure 4. Mean component scores (± SE) for both synchronous and asynchronous conditions and for each interoceptive sensitivity group (HIGH and LOW groups) in Experiment 2.