Rostral anterior cingulate activity generates posterior versus anterior theta activity linked to agentic extraversion

Abstract

Recent research using the resting electroencephalogram (EEG) showed that posterior versus anterior theta activity (around 4-8 Hz) is consistently associated with agency, reflecting the dopaminergic core of extraversion (i.e., incentive motivation, positive emotion). Neuroimaging studies using various methodologies and experimental paradigms have converged on the anterior cingulate cortex (ACC) as a neurophysiological correlate of extraversion. The aim of the present study is integrate these lines of research by testing the hypothesis that posterior versus anterior EEG theta is at least partly based on ACC theta activity. Resting EEG data were analyzed in N = 78 healthy, male participants extremely high or low in agentic extraversion (aE). Using the low-resolution electromagnetic tomography algorithm, we localized the sources of aE-dependent intracerebral theta activity within rostral subdivisions of the ACC. The posterior versus anterior index and theta current density within the rostral ACC were significantly correlated (r = -.52), and both displayed high retest stability across 5 hr and were associated with traits from the aE spectrum. These neurophysiological correlates of aE and their possible functional significance are discussed.

Midline theta dissociates agentic extraversion and anhedonic depression

“…Consistent with DA-models of agency (Depue & Collins, 1999), the FzPz index and its relationship to agency are sensitive to DA (Wacker et al, 2006). Further, a source localization study suggests that the rostral anterior cingulate cortex is the primary generator of the FzPz index (Chavanon et al, 2011). Although altered rostral ACC theta and delta activity during rest has been reported in healthy subjects with anhedonic symptoms (Wacker et al, 2009), the correlation between the FzPz index and anhedonia was not significant in the present study of healthy and depressed participants.…”

“…While agency was unrelated to feedback-evoked theta alterations, there was a negative correlation between agency and the feedback-independent FzPz index as in a number of prior studies on resting EEG . This correlation is typically most pronounced for the agency facet of extraversion (Chavanon et al, 2011;Knyazev, Bocharov, & Pylkova, 2012) and -as in the present study -always indicates enhanced relative frontal theta power in intro-versus extraverts. Consistent with DA-models of agency (Depue & Collins, 1999), the FzPz index and its relationship to agency are sensitive to DA (Wacker et al, 2006).…”

“…In addition to feedback-evoked theta, the FzPz index, a feedback-independent measure of frontal versus parietal theta topography is a potentially relevant marker as it has been consistently associated with agency and shown to be modulated by DA (Chavanon, Wacker, & Stemmler, 2011;Wacker et al, 2006Wacker et al, , 2010. Whether the FzPz index relates to anhedonia has not yet been tested, although there is some evidence for altered theta activity in healthy individuals with high vs. low anhedonia (Wacker, Dillon, & Pizzagalli, 2009).…”

Functional neuroimaging of extraversion-introversion

“…Intriguingly, this study showed that the source of intracerebral θ was localized within the rostral subdivisions of the ACC. The current density of θ within the rostral ACC was significantly correlated with the agentic extraversion spectrum, and had high retest stability during 5 h [30] .…”

“…The results showed that the extraversion-related differences in the loadresponsivity pattern were reversed by sulpiride, and the effect was especially large in frontal areas. A recent EEG study was extended to the θ rhythm (4-8 Hz) to investigate the interaction between personality and cognitive performance [30] . Intriguingly, this study showed that the source of intracerebral θ was localized within the rostral subdivisions of the ACC.…”