To test these hypotheses, Tugade and Fredrickson (2004) collected continuous measures of cardiovascular responding from all participants (N = 57) at a sampling rate of 1000 Hz. Six indices of cardiovascular responding were collected, including (1) heart rate (HR), (2) finger pulse amplitude (FPA), (3) pulse transmission times to the finger (PTF), (4) pulse transmission time to the ear (PTE), (5) diastolic blood pressure (DBP), and (6) systolic blood pressure (SBP). After a resting baseline, anxiety was experimentally induced by inmate dating agency Australia telling participants that they would have 60 sec to mentally prepare a speech on a self-relevant topic. Following the 60-sec, speech-preparation task, there was a 3-min recovery period. Participants also completed self-reports of subjective emotional experience, ambient positive and negative mood (PANAS; Watson, Clark, & Tellegen, 1989), and trait resilience (Block & Kremen, 1996).
Findings indicated that, across all participants, the speech preparation task produced subjective experiences of anxiety and increases in cardiovascular reactivity from baseline (see Table 1 ). These changes reflect task-induced, cardiovascular arousal, which includes heart rate acceleration, increased blood pressure, and peripheral vasoconstriction.
Table 1
Note. Reproduced with permission from the APA. HR = heart rate in beats per min; FPA = finger pulse amplitude in mv; PTF = pulse transmission time to the finger and PTE = pulse transmission time to the ear, each in msec; DBP = diastolic blood pressure and SBP = systolic blood pressure, each in mmHg. Asterices indicate changes significantly different form baseline measures by within-subject t-tests (df = 55).
Our first prediction was that trait resilience would predict subjective reports of positive emotionality. Results revealed support for this prediction: Trait resilience was positively associated with positive mood as assessed by the PANAS (Watson et al., 1988) (r = .38, p<.01), (but not associated with negative mood). Adding further support to our first prediction, we found that higher trait resilience was associated with more happiness (r = .47, p<.01) and more interest (r = .33, p<.01) during the speech preparation task. To quantify positive emotionality in a single measure, we created a composite index by summing the standardized scores of positive mood and standardized emotion reports of happiness in response to the speech preparation task. 1 As predicted, trait resilience was positively related to the positive emotionality composite index (r = .46, p<.001).
Taken together, self-report and physiological data indicate that the speech-preparation task induced anxiety and cardiovascular reactivity that was significantly different from baseline levels; these variables did not vary based on sex and trait resilience
Our second prediction was that psychological resilience would be negatively related with duration of cardiovascular reactivity. We calculated an aggregate index of duration of cardiovascular reactivity (time to return to baseline levels) for each participant by computing the mean duration score across the six cardiovascular indices (for a detailed description of this data-reduction technique, see Fredrickson & Levenson, 1998). As predicted, findings demonstrated that trait resilience was negatively correlated to duration of cardiovascular reactivity (r = ?.26, p<.05), indicating that those with higher trait resilience evidenced faster cardiovascular recovery from negative emotional arousal.
Our final prediction stated that positive emotions would mediate the effect of resilience on duration of cardiovascular reactivity following the speech-preparation task. The statistical analysis framework suggested by Baron and Kenny (1986) was used to test for mediation effects. Findings revealed support for our final prediction: Data indicated that the effect of trait resilience on duration of cardiovascular reactivity was no longer significant when controlling for positive emotionality (Beta = ?.15, t<1, ns) (for full details of the test of mediation, please refer to Tugade & Fredrickson, 2004).