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. 2015 Mar 6;10(3):e0119466. doi: 10.1371/journal.pone.0119466

Table 3. Inferential statistics for valence and arousal measures across participants and as related to self-reported mindfulness (FFMQ-NR).

Affective Reactivity Measure Hypothesis df F P ηp 2 Mdiff 95% CI
Lower Upper
Valence Effects
Self-reported valence: Rating
Main effect of emotion (2, 98) 418.2 0.001 0.895
Valence contrast Ple > Unp (1, 49) 502.5 0.001 0.911 3.95 3.60 4.30
FFMQ–NR x Valence contrast High < Low (1, 49) 0.1 0.707 0.003 -0.10 -0.81 0.61
Startle response: EMG
Main effect of emotion (2, 98) 17.5 0.001 0.263
Main effect of interval (2, 98) 23.2 0.001 0.321
Valence contrast Unp > Ple (1, 49) 26.6 0.001 0.352 2.09 1.29 2.90
FFMQ–NR x Valence contrast High < Low (1, 49) 0.1 0.943 0.001 -0.02 -1.65 1.61
Arousal Effects
Self-reported arousal: Ratings
Main effect of emotion (2, 98) 86.2 0.001 0.637
Arousal contrast Aro > Neu (1, 49) 140.4 0.001 0.741 1.90 1.58 2.22
FFMQ–NR x Arousal contrast High < Low (1, 49) 0.1 0.903 0.001 -0.09 -0.73 0.56
Sympathetic arousal: SCR
Main effect of emotion (2, 94) 13.6 0.001 0.225
Arousal contrast Aro > Neu (1, 47) 23.2 0.001 0.330 0.54 0.31 0.77
FFMQ–NR x Arousal contrast High < Low (1, 47) 1.0 0.319 0.021 0.09 -0.37 0.54
Early posterior negativity: EPN
Main effect of emotion (2, 98) 19.2 0.001 0.282
Arousal contrast Neu > Aro (1, 49) 24.6 0.001 0.334 1.43 0.84 2.01
FFMQ–NR x Arousal contrast High < Low (1, 49) 2.4 0.128 0.047 -0.72 -1.89 0.44
Motivated attention to pictures: LPP
Main effect of emotion (2, 98) 19.9 0.001 0.288
Arousal contrast Aro > Neu (1, 49) 40.4 0.001 0.452 1.11 0.77 1.46
FFMQ–NR x Arousal contrast High < Low (1, 49) 0.1 0.812 0.001 -0.03 -0.74 0.67
Attention to startle probes: P3
Main effect of emotion (2, 98) 2.2 0.112 0.044
Main effect of interval (2, 98) 5.8 0.005 0.105
Arousal contrast Neu > Aro (1, 49) 0.3 0.594 0.006 0.10 -0.27 0.46
FFMQ–NR x Arousal contrast High < Low (1, 49) 1.84 0.181 0.036 0.19 -0.54 0.92

N = 51 (except for SCR, N = 49). FFMQ-NR = Nonreactivity subscale of the FFMQ; Unp = unpleasant pictures; Ple = pleasant pictures; Neu = neutral pictures; Aro = unpleasant + pleasant pictures combined. Note that the inferential statistics (i.e., df, F, p, and η p 2) are taken from an ANCOVA with Emotion (i.e., picture category) as within-subjects factor (and also with Interval for EMG and P3) and FFMQ-NR as a continuous and centered covariate (to maximize power). “Mdiff” refers to the mean differences between conditions or groups specified under “Hypothesis.” Accordingly, valence and arousal contrasts refer to the hypothesized differences between picture categories across participants. For all measures, these Mdiff scores across participants were expected to be positive. To illustrate the moderating effects of FFMQ-NR, a median split was performed and difference scores for individuals with low scores (n = 26) were subtracted from difference scores for individuals with high scores (n = 25). Because for all measures, the main hypothesis was that high FFMQ-NR individuals would show lower affective reactivity than low FFMQ-NR individuals, only negative Mdiff scores were expected for the interactions between FFMQ-NR and the valence or arousal contrasts.