1. Materials and Methods Background Distinct cerebellar lobules encode arousal and valence in specific time windows: an MEG study. Styliadis C. 1, Ioannides A. A. 2, Bamidis P. D. 1, Papadelis C. 3 1 Laboratory of Medical Physics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Greece 2 Laboratory for Human Brain Dynamics, AAI Scientific Cultural Services Ltd., Nicosia, Cyprus 3 Department of Neurology, Boston Children’s Hospital, Harvard Medical School, MA, USA i.Cerebellum contributes significantly to cognitive and emotional functions (demonstrated by recent anatomical (for a review see Strick et al., 2009), functional (for a metanalysis see Stoodley & Schmahmann, 2009), and clinical (Schmahmann & Sherman, 1998) studies). ii.The cerebellar role within the emotion-related distributed circuit has been shown for at least two independent emotional dimensions, arousal and valence (Colibazzi et al., 2010). iii.The functional specificity of cerebellar lobules for emotions has been demonstrated in a similar manner to the specificity that cortical and subcortical regions present (Moulton et al., 2011; Bauman & Mattingley, 2012). iv.The temporal component of the functional specificity of the cerebellar lobules for emotional processing has not been studied. This component is critical for the adequate understanding of the nature of emotional processing (Davidson, 1998). Hypothesis: We hypothesized that different levels of arousal and valence activate distinct cerebellar lobules within specific time windows in a sequence determined by the arousal and valence content of the affective experience. Difference between high and low arousal. Conclusions References Sliding window analysis for a time window of 1000 ms with a step of 10 ms Difference between high and low arousal. MEG sensor space Group-averaged time frequency of induced activity of arousal after onset on representative sensors that cover the cerebellum in CTF151 layout. Changes significant at p<0.05 level (cluster correction) are indicated within dotted lines. MEG virtual sensor space Group-averaged time frequency of induced activity of arousal after onset for Left Crus II (-16, -86, -35). Changes significant at p<0.05 level (cluster correction) are indicated within dotted lines. Results High ArousalHigh Arousal and Pleasant ValenceUnpleasant Valence Static window analysis. Group analysis activation (red-yellow blobs, p<0.001 uncorrected) High Arousal High Arousal and Pleasant Valence The novel spatiotemporal evolution of cerebellar activations highlights that: (i)arousal, valence, and their interaction are functionally represented on anatomically distinct cerebellar lobules (ii)the encodings of arousal, valence, and their interaction unfold at well- defined latencies relative to stimulus onset and evolve in parallel within the cerebellum (iii)emotion-related cerebellar responses are hierarchically organized into an early prioritization of high arousal, followed by an unpleasant valence effect and later a pleasant valence by high arousal interaction effect. Baumann, O., & Mattingley, J. B. (2012). Functional topography of primary emotion processing in the human cerebellum. Neuroimage, vol. 61, no. 4, pp. 805-811. 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Subjects: 10 healthy adults (5 females; age range, 21 to 40 years; mean age, 28.5; S.D., 5.94) Stimuli: 160 stimuli from International Affective Picture System (IAPS). 4 groups manipulating the level of arousal within pleasant and unpleasant pictures: (i) pleasant with high arousal (PHA, (ii) pleasant with low arousal (PLA), (iii) unpleasant with high arousal (UHA) and (iv) unpleasant with low arousal (ULA). Balanced for gender differences and perceptual features. Synthetic Aperture Magnetometry (SAM), Normalization, Group Analysis, Virtual Sensors Funded by the Operational Program “Education and Lifelong Learning” of the Greek Ministry of Education and Religious Affairs, Culture and Sports (ref. number 2012ΣΕ24580284). Contact:styliadis@hotmail.com Stimuli rating Experimental Design Sliding Window Analysis Static Window Analysis MEG recordings: 151-channel CTF whole head system (VSM MedTech Ltd, B.C., Canada) at a sampling rate of 1250 Hz. Time frequency Analysis: Wavelet analysis (factor 3) applied on single trials for revealing induced activity. Source reconstruction: Dual state Synthetic Aperture Magnetometry (SAM) for an active time window of 0-1000 ms after stimulus onset at the gamma frequency band (30-100 Hz). Statistical analysis: 2x2 repeated measures of ANOVA using SPM with a statistical threshold of p<0.001 uncorrected. Virtual Sensors: Virtual sensors on significant cerebellar lobules