Biological Psychology 94 (2013) 198–209 Contents lists available at SciVerse ScienceDirect Biological Psychology journa l h om epa ge: www.elsevier.com/locate/biopsycho Relations among EEG-alpha asymmetry, BIS/BAS, and dispositional optimism Vilfredo De Pascalis ∗ , Giuseppe Cozzuto, Gian Vittorio Caprara, Guido Alessandri Department of Psychology, “La Sapienza”, University of Rome, Italy a r t i c l e i n f o Article history: Received 27 August 2012 Accepted 27 May 2013 Available online 2 June 2013 Keywords: EEG-alpha sLORETA BIS/BAS Optimism a b s t r a c t Past research has been unable to address whether the activity in the frontal hemispheres is related to the direction of motivation (approach versus withdrawal) or valence of emotion (positive versus negative). The present study was an attempt to address this question by using a standardized low-resolution brain electromagnetic tomography (sLORETA) which provides EEG localization measures that are independent of the recording reference. Resting EEG, self-report measures of Behavioral Activation and Inhibition Sys- tem (BAS and BIS) strength, dispositional optimism and a measure of hedonic tone, were collected from 51 unselected undergraduates. Three measures of cortical activation were obtained: (a) alpha asymme- try at conventional scalp sites, (b) anterior and posterior source alpha asymmetries (sLORETA method), (c) posterior versus frontal delta and theta activity. Both alpha asymmetry measures (conventional EEG and sLORETA) yielded significant frontal and parietal asymmetry correlation patterns. Neither measure identified significant associations between resting posterior versus frontal delta and theta activity per- sonality traits. Higher BAS was uniquely related to greater left-sided activation in the middle frontal gyrus (BA11). Optimism was associated with higher activations in the left-superior frontal gyrus (BA10) and in the right-posterior cingulate cortex (BA31). © 2013 Elsevier B.V. All rights reserved. 1. Introduction A main question in psychophysiology research concerns how individual differences in hemispheric asymmetry are manifested in motivation and personality. One dominant theory elaborated by Gray and colleagues, named the “reinforcement sensitivity the- ory” (RST; Corr, 2004; Gray & McNaughton, 1996; Gray, 1982, 1987; McNaughton & Corr, 2004), suggested the operation of two general systems for coordinating adaptive behavior. The first sys- tem is referred to as the Behavioral Inhibition System (BIS). This system is sensitive to signals of conditioned punishment, nonre- ward, novelty, and innate fear stimuli. Its function is to increase attention toward aversive stimuli, to interrupt ongoing behav- ior and prepare for vigorous action, while processing potential threat cues. A second system has been referred to as the Behav- ioral Activation System (BAS; Fowles, 1980, 1988) or, alternatively, the Behavioral Approach System (Gray, 1982). The BAS is believed to mediate the experience of positive affect. Individual variation in the BAS predicts approach-related behavior and positive emo- tion in response to reward cues. In the present study, the measures ∗ Corresponding author at: Department of Psychology, “La Sapienza”, University of Rome, Via dei Marsi 78, 00185 Roma, Italy. Tel.: +39 06 76907199; fax: +30 06 49917711. E-mail address: vilfredo.depascalis@uniroma1.it (V. De Pascalis). of individual differences in behavioral approach and inhibition sensitivities are Carver and White’s (1994) BIS/BAS scales. The BIS and BAS scales have been shown to predict reports of anx- iety and happiness, respectively, in the presence of situational cues of impending threat and impending reward (Carver & White, 1994). Across the years, several parallel multifaceted dispositional measures have been proposed, within the framework of the behav- ioral approach construct, as appropriate and useful indicators of the individual tendency to experience positive emotions and well-being. Among these, a measure of dispositional optimism, as obtained by the Life Orientation Test-Revised (LOT-R, Scheier, Carver, & Bridges, 1994), is an important but neglected indicator of constructs related to approach behavior. Optimism corresponds to a general orientation toward generalized positive expectations for the future in which one believes that good things will be plentiful and bad things scarce (Scheier & Carver, 1992). Excess of opti- mism can be harmful as it can promote an underestimation of risk and low planning (Lovallo & Kahneman, 2003). In contrast, a pes- simistic look is correlated with severity of depression symptoms (Drevets et al., 1997). A moderate optimistic view, however, can motivate adaptive behavior in the present toward a future goal, and has been related to physical and mental health (Scheier & Carver, 1987). Although optimism is conceptualized as a disposition linked to the BIS/BAS construct, measures of these latter traits are not 0301-0511/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.biopsycho.2013.05.016