ORIGINAL PAPER Inability to Process Negative Emotions in Cerebellar Damage: a Functional Transcranial Doppler Sonographic Study Michela Lupo & Elio Troisi & Francesca R. Chiricozzi & Silvia Clausi & Marco Molinari & Maria Leggio # Springer Science+Business Media New York 2015 Abstract Recent studies have implicated the cerebellum as part of a circuitry that is necessary to modulate higher order and behaviorally relevant information in emotional domains. However, little is known about the relationship between the cerebellum and emotional processing. This study examined cerebellar function specifically in the processing of negative emotions. Transcranial Doppler ultrasonography was per- formed to detect selective changes in middle cerebral artery flow velocity during emotional stimulation in patients affected by focal or degenerative cerebellar lesions and in matched healthy subjects. Changes in flow velocity during non- emotional (motor and cognitive tasks) and emotional (relaxing and negative stimuli) conditions were recorded. In the present study, we found that during negative emotional task, the he- modynamic pattern of the cerebellar patients was significantly different to that of controls. Indeed, whereas relaxing stimuli did not elicit an increase in mean flow velocity in any group, negative stimuli increased the mean flow velocity in the right compared with left middle cerebral artery only in the control group. The patterns by which mean flow velocity increased during the motor and cognitive tasks were similar within pa- tients and controls. These findings support that the cerebellum is part of a network that gives meaning to external stimuli, and this particular involvement in processing negative emotional stimuli corroborates earlier phylogenetic hypotheses, for which the cerebellum is part of an older circuit in which neg- ative emotions are crucial for survival and prepare the organ- ism for rapid defense. Keywords Cerebellum . Emotional task . Middle cerebral artery . Blood flow velocity . Focal cerebellar lesion Introduction For several decades, the debate over hemispheric asymmetries for emotion perception and identification has been going on. In the last years of the nineteenth century, clinical evidence in patients with unilateral cortical damage suggested that the right hemisphere (RH) is specialized in perceiving, express- ing, and experiencing emotions [1]. More recently, it has been advanced the hypothesis that the RH processes all basic emo- tions (positive and negative) and is the seat of subjective affect (feeling) [2–6]. In regard to the left hemisphere (LH), contra- dictory findings make its contributions to emotional process- ing highly debatable (i.e., whether the LH does not differenti- ate between emotional and neutral faces [7] or only processes positive emotions [2]). Within this framework, interesting insights derive from neuroimaging studies that showed a widespread distribution of neural activity associated with emotional tasks and involv- ing both hemispheres (i.e., see meta-analysis [8, 9]). Elizabeth Shobe (2014) proposed a qualitatively different involvement of each hemisphere in emotional processing. Ac- cording to her model, the RH directly mediates the identifica- tion and comprehension of positive and negative emotional stimuli, whereas the LH contributes to higher level processing of emotional information that has been shared via the corpus M. Lupo : F. R. Chiricozzi : S. Clausi : M. Leggio Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy M. Lupo : F. R. Chiricozzi : S. Clausi : M. Leggio (*) Ataxia Laboratory, IRCCS Santa Lucia Foundation, 00179 Rome, Italy e-mail: maria.leggio@uniroma1.it E. Troisi IRCCS Santa Lucia Foundation, 00179 Rome, Italy M. Molinari Neurological and Spinal Cord Injury Rehabilitation Department A, IRCCS Santa Lucia Foundation, 00179 Rome, Italy Cerebellum DOI 10.1007/s12311-015-0662-z