Chambers, A. S., & Allen, J. J. (2007). Cardiac vagal control, emotion, psychopathology, and health. Biological Psychology, 74(2), 113-115.
Coan, J. A., J., J., & Harmon-Jones, E. (2001). Voluntary facial expression and hemispheric asymmetry over the frontal cortex. Psychophysiology, 38(6), 912-925.
PMID: 12240668;Abstract:
Brain activity was monitored while 36 participants produced facial configurations denoting anger, disgust, fear, joy, and sadness. EEG alpha power was analyzed during each facial pose, with facial conditions grouped according to the approach/withdrawal motivational model of emotion. This model suggests that "approach" emotions are associated with relatively greater left frontal brain activity whereas "withdrawal" emotions are associated with relatively greater right frontal brain activity. In the context of a bilateral decrease in activation, facial poses of emotions in the withdrawal condition resulted in relatively less left frontal activation in the lateral-frontal, midfrontal and frontal-temporal-central region, but not in the parietal region, as predicted. Findings in the approach condition were less consistently supportive of predictions of the approach/withdrawal model. Implications for the approach/withdrawal model and for the emotion eliciting potential of voluntary facial movement are discussed.
Reznik, S. J., & Allen, J. J. (2018). Frontal asymmetry as a mediator and moderator of emotion: An updated review. Psychophysiology, 55(1).
Schafer, S. M., Wager, T. D., Mercado Jr, R. A., Thayer, J. F., Allen, J. J., & Lane, R. D. (2015). Partial Amelioration of Medial Visceromotor Network Dysfunction in Major Depression by Sertraline. Psychosomatic medicine, 77, 752--761.
Allen, J., Towers, D. N., & Allen, J. J. (2009). A better estimate of the internal consistency reliability of frontal EEG asymmetry scores. Psychophysiology, 46(1).
Frontal alpha asymmetry is typically computed using alpha power averaged across many overlapping epochs. Previous reports have estimated the internal consistency reliability of asymmetry by dividing resting EEG sessions into segments of equal duration (e.g., 1 min) and treating asymmetry scores for each segment as "items" to estimate internal consistency reliability using Cronbach's alpha. Cronbach's alpha partly depends on the number of items, such that this approach may underestimate reliability by using less than the number of distinct items available. Reliability estimates for resting EEG data in the present study (204 subjects, 8 sessions) were obtained using mean split-half correlations with epoch alpha power as treated as separate items. Estimates at all scalp sites and reference schemes approached .90 with as few as 100 epochs, suggesting the internal consistency of frontal asymmetry is greater than that previously reported.
