Motivational mechanisms (BAS) and prefrontal cortical activation contribute to recognition memory for emotional words. rTMS effect on performance and EEG (alpha band) measures Michela Balconi a,b,⇑ , Chiara Cobelli b a Research Unit in Affective and Social Neuroscience, Department of Psychology, Catholic University of Sacred Heart, Milan, Italy b Laboratory of Cognitive Psychology, Department of Psychology, Catholic University of the Sacred Heart, Milan, Italy article info Article history: Accepted 11 August 2014 Available online 3 September 2014 Keywords: Emotional word Recognition BAS Lateralization Alpha band DLPFC abstract The present research addressed the question of where memories for emotional words could be repre- sented in the brain. A second main question was related to the effect of personality traits, in terms of the Behavior Activation System (BAS), in emotional word recognition. We tested the role of the left DLPFC (LDLPFC) by performing a memory task in which old (previously encoded targets) and new (previously not encoded distractors) positive or negative emotional words had to be recognized. High-BAS and low-BAS subjects were compared when a repetitive TMS (rTMS) was applied on the LDLPFC. We found significant differences between high-BAS vs. low-BAS subjects, with better performance for high-BAS in response to positive words. In parallel, an increased left cortical activity (alpha desynchronization) was observed for high-BAS in the case of positive words. Thus, we can conclude that the left approach-related hemisphere, underlying BAS, may support faster recognition of positive words. Ó 2014 Elsevier Inc. All rights reserved. 1. Introduction Only a limited number of researchers have addressed the topic of where memories for emotional words could be represented in the brain (Balconi & Ferrari, 2012a; Balconi, Ferrari, & Amenta, 2010; Gray, Braver, & Raichle, 2002). This debate is still open, and a new approach that focuses on the interaction of emotions, memories and personality components has recently received attention, with particular reference to the effect of emotional con- tent in terms of valence (positive vs. negative) of the emotional words (Balconi & Ferrari, 2012b; Hariri, Bookheimer, & Mazziotta, 2000), on the one hand, and of personality traits on the other hand (Balconi & Ferrari, 2013; Davidson & Irwin, 1999). Regarding the cortical correlates, the present study analyzed the role of the prefrontal network (Dorsolateral Prefrontal Cortex, DLPFC) on emotional memory performance when subjects engaged in memory recognition of emotional words. From a neuropsycho- logical point of view, several studies have shown that the prefron- tal cortex (PFC) plays a crucial role in the integration of different aspects of cognition, memory, and emotional regulation by manag- ing the cognitive control over emotional stimuli and emotional behavior (Balconi, 2013; Kalish & Robins, 2006; Knight, Staines, Swick, & Chao, 1999; Miller & Cohen, 2001). Specifically regarding memory function, neuropsychological and lesion studies have documented the involvement of the frontal lobes in recognition memory. Neuroimaging, Transcranial Magnetic Stimulation (TMS), and transcranial direct current stimulation (tDCS) research has shown that the DLPFC is involved in the recog- nition process (Javadi & Walsh, 2011; Sandrini, Cappa, Rossi, Rossini, & Miniussi, 2003; Turriziani, Smirni, Oliveri, Semeza, & Cipolotti, 2010). With regard to the contributions of these brain areas in specific memory tasks, neuroimaging studies have shown increased activation of the DLPFC during tasks that require the organization of information and the need to manage the relation- ships between memory cues. This process of manipulation pro- motes the strengthening of inter-item associations, resulting in enhanced memory formation (Blumenfeld & Ranganath, 2006). Considering emotional memories, models for the processing of emotional information have suggested that a network of intercon- nected neuroanatomical regions – including the amygdala, hippo- campus, thalamus, anterior cingulate cortex, and PFC – cooperate to process emotional information and emotional memories (Davis, 1992; LeDoux, Cicchetti, Xagoraris, & Romanski, 1990; Skipper & Olson, 2014). Top-down control by the PFC on the amygdale allows for the cognitive modulation of emotional pro- cesses by frontal brain structures, and the PFC could be crucial http://dx.doi.org/10.1016/j.bandl.2014.08.006 0093-934X/Ó 2014 Elsevier Inc. All rights reserved. ⇑ Corresponding author at: Department of Psychology, Catholic University of the Sacred Heart, Milan, Largo Gemelli, 1, 20123 Milan, Italy. Fax: +30 2 72342280. E-mail address: michela.balconi@unicatt.it (M. Balconi). Brain & Language 137 (2014) 77–85 Contents lists available at ScienceDirect Brain & Language journal homepage: www.elsevier.com/locate/b&l