The existence of specific somatic states associated with different emotions remains controversial. In this study, we investigated the profile of cardiorespiratory activity during the experience of fear, anger, sadness and happiness. ECG and respiratory activity was recorded in 43 healthy volunteers during the recall and experiential reliving of one or two potent emotional autobiographical episodes and a neutral episode. Univariate statistics indicated that the four emotions differed from each other and from the neutral control condition on several linear and spectral indices of cardiorespiratory activity. Dependent variables were further reduced to five physiologically meaningful factors using an exploratory principal component analysis (PCA). Multivariate analyses of variance and effect size estimates calculated on those factors confirmed the differences between the four emotion conditions. A stepwise discriminant analyses predicting emotions using the PCA factors led to a classification rate of 65.3% for the four emotions (chance=25%; p=0.001) and of 72.0-83.3% for pair-wise discrimination (chance=50%; p's<0.05). These findings may be considered preliminary in view of the small sample on which the multivariate approach has been applied. However, this study emphasizes the need to better characterize the multidimensional factors involved in cardio-respiratory regulation during emotion. These results are consistent with the notion that distinct patterns of peripheral physiological activity are associated with different emotions.
http://www.ncbi.nlm.nih.gov/pubmed/16439033
