Convergent Findings in Passive and Active Processing of the Dominance Dimension of Emotion

1. Convergent Findings in Passive and Active Processing of the Dominance Dimension of Emotion Matthew Jerram, Alyson Negreira, David Gansler Brain Image Analysis Laboratory, Suffolk University, Boston, MA Introduction Emotion can be elicited by both passive and active methods. Passive methods require the participant to observe stimuli without directly assessing or responding to it. Active methods ask the participant to utilize cognitive methods to elicit an emotional response. In general, active methods are primarily associated with cognitive appraisal, or top-down, aspects of emotional experience. Passive methods tend to primarily activate bottom-up aspects of emotion. Both bottom-up and top-down channels of emotion processing work in tandem to produce emotional experience. Emotions can be conceptualized as the conjunction of three dimensions (dominance, valence and arousal). Dominancerefers to the level to which the individual feels that he or she can influence a situation or has control of the external environment during the emotional experience. Mehrabian (1974) described it as “feelings of control and influence over everyday situations, events and relationships versus feelings of being controlled and influenced by circumstances and others”. Emotional dominance is more closely associated with the cognitive appraisal of a stimulus than valence or arousal. Valence and arousal have been investigated with neuroimaging but the regions associated with the neural correlates of dominance are relatively unknown. To better understand the neurological substrate of emotional dominance, identifying regions convergently activating in response to bottom-up and top-down processing is an important step. Passive Processing Active Processing RH: 8, -78, 40 Methods Two fMRI studies were performed. In Study 1, seventeen right-handed healthy male participants (age range = 20 – 35) were scanned on a 3T scanner at Tufts Medical Center. Each participant underwent three 5-minute runs during which International Affective Picture System (IAPS) images chosen based on previously published agency ratings (high or low) were presented. Images selected were matched on average valence levels to ensure that activations observed were related to changes in agency. Images were presented in a block A-B-A-B design of high and low agency images. Each block lasted for 30 seconds, during which 6 images were presented for 1-5 seconds each and participants were asked to respond by button-press when the image changed. SPM8 was used to analyze these data and the low>high dominance contrast is presented here. In Study 2, fourteen right-handed healthy male participants (age range = 20 – 35) were scanned on a 3T scanner at McLean Imaging Center.Participants viewed IAPS images during fMRI. Four conditions were created using IAPS normative ratings: (1) passive viewing of negative valence, negative dominance, (2) passive viewing of neutral valence, neutral dominance, (3) top down processing of neutral valence, neutral dominance where the participant was instructed to make themselves feel more negative, and (4) top down processing of neutral valence, neutral dominance where the participant was instructed to make themselves feel less dominant. FreeSurfer, v. 5, was used to analyze these data and the decrease dominance>passive neutral contrast is presented here. RH:9, -59, 40 6, -59, 30 LH: -7, -63, 36 Discussion Across the two studies, the precuneus was consistently observed in response to decreased emotional dominance. This region is involved with self-reflection and consciousness, especially in terms of modeling the perspectives of others (Jeannerod, 2007). Cavanna & Trimble (2006) found support for the association of precuneus with visuo-spatial imagery, episodic memory retrieval, theory of mind and is also part of the brain’s default mode network (Buckner et al., 2008). Precuneus activation has also been observed in response to the attribution of an action to another person (Farrar & Frith, 2002). The precuneus may involve the attempt to model the likely actions of others when one expects to have little or no influence. The bilateral activation in the active condition processing relative to the unilateral processing in the passive condition is consistent with the increased cognitive/emotional interaction that is required for the top-down processing of the active condition. Results Analysis revealed significant activation in the right precuneus during both passive and active processing of emotional dominance. Significant activity in the left precuneus was also observed in active processing. In both studies, activity was associated with decreased emotional dominance.