@MASTERSTHESIS\{IMM2013-06636, author = "N. Mersebak", title = "Analysis of Social {EEG} - A Neuroscience Study", year = "2013", school = "Technical University of Denmark, Department of Applied Mathematics and Computer Science / {DTU} Co", address = "Matematiktorvet, Building 303B, {DK-}2800 Kgs. Lyngby, Denmark, compute@compute.dtu.dk", type = "", note = "{DTU} supervisors: Lars Kai Hansen, lkai@dtu.dk, Co-supervisors: Carsten Stahlhut and Ivana Konvalinka, {DTU} Compute", url = "http://www.compute.dtu.dk/English.aspx", abstract = "The thesis describes a neuroscience study investigating how the presence of another person will effect people’s perception of emotional scenes. Will one become more attentive towards the emotional scenes and will they be perceived as more or less extreme? These questions are answered from a 2  3 within-subjects experimental design with the social context (Alone and Together) and the emotional picture content (Positive, Negative and Neutral) as the two factors. Consistent with similar studies, the emotional picture content is found to modulate how the information is perceived. From an {ERP} analysis, the {LPP} distinguishes the affective pictures compared to the neutral pictures. It is suggested to be an enhanced attraction of attentional neural resources for processing the emotional content. Source reconstruction showed increased activity for positive pictures in the left frontal midline gyrus compared to neutral ones. The left frontal midline is suggested to be in a network with the limbic system creating emotional states. The thesis is the first to study how the neural responses are modulated when attending {IAPS} pictures with another person. From a cluster-based permutation test, a decrease of the {LPP} (p=0.04) is found when jointly attending the pictures, which reflects a decrease of the arousal state. Source reconstruction localized the differences to the left frontal superior gyrus, the left frontal midline gyrus, the left occipital midline gyrus, the right temporal superior gyrus and the right temporal midline gyrus, which are areas associated with regulation of the emotional state and the {MNS} system. A time-frequency analysis showed that the presence of another person increased the attention towards negative pictures (p=0.06) reflected as decreased alpha power." }