P218 Cerebellar involvement in facial emotion discrimination: A TMS study

Abstracts / Clinical Neurophysiology 128 (2017) e1–e163

Two components concur in such capacity: an imitative pattern of behavior, based on parieto-frontal circuitry, and a non-imitative modality. Objective: In this experiment we investigate the neural substrates of the capacity to override imitative tendencies and perform nonimitative behavior. Materials and methods: In a first, localizer experiment, We challenged healthy human participants in an imitative (i.e. stimulus dependent) and a non-imitative (i.e. rule-dependent) task while undergoing functional magnetic resonance imaging (fMRI). A complex cortical network comprising the ventral prefrontal, the premotor, parietal, superior temporal and lateral occipital cortices showed increased activation during non-imitative, compared to imitative behavior. In a second experiment we applied 20 min of 1 Hz repetitive transcranial magnetic stimulation (rTMS) to the left ventral prefrontal cortex as indicated by experiment 1, and immediately after underwent fMRI while performing the imitative and the nonimitative tasks. Results: We observed that differences in blood-oxygen-leveldependent (BOLD) signal between the two tasks were significantly modulated by the prior application of rTMS to the prefrontal cortex. Sites showing such rTMS*task interactions in BOLD signal included the ventral and anterior prefrontal cortex, the parietal and premotor regions bilaterally, the pre-supplementary motor area, the posterior superior temporal cortex. Conclusion: Local modulation of neural activity in the prefrontal cortex by rTMS generated a cascade of events in a cortical network that is likely to support our capacity to perform flexible nonimitative behavior. doi:10.1016/j.clinph.2016.10.332

P216 Do repetitive spinal motor neuron discharges underlie the facilitation and inhibition in paired-pulse paradigm?—E.T. Batzianouli *, N.A. Nguepnjo Nguissi, B. Miaz, D. Benninger (Centre Hospitalier Universitaire Vaud (CHUV), Clinical Neurosciences, Lausanne, Switzerland) ⇑

Corresponding author.

Objective: To explore whether repetitive Motorneuron Discharges (repMDs) contribute to intracortical facilitation (ICF) and short intracortical inhibition (SICI). Background: Transcranial magnetic stimulation (TMS) leads to repetitive spinal motor neuron discharges (repMNDs). The pairedpulse TMS (PP-TMS) paradigm allows the exploration of the motor cortex physiology, but the precise mechanisms remain undetermined. The triple stimulation technique (TST) and an extended TST-technique including a 4th and 5th stimulation, Quadruple (QuadS) and Quintuple (QuintS) stimulation, respectively, allow a more precise exploration of the central motor conduction and of repMNDs. Design/methods: We explored the PP TMS paradigms of short intracortical inhibition (SICI) with an inter-stimulus interval (ISI) of 2 ms and intracortical facilitation (ICF) with an ISI of 10 ms in the conventional way (TMS), combined with the TST, the QuadS and QuintS in a randomized design in 20 healthy volunteers. Results: TMS and TST paradigms confirm the ICF and SICI and they appear to be associated with more repMNDs in ICF than in SICI. About half of the subjects have repMND following a single pulse TMS in the QuadS and QuintS condition (60% and 40%, respectively) and generally more in the QuadS than in the QuintS condition. There

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appear more repMNDs in the PP-TMS paradigm of ICF than with a single pulse TMS and less than latter in SICI. Conclusions: Our preliminary results suggest a possible contribution of repetitive spinal motor neuron discharges in the conditioned responses of PP-TMS, but there is an inter- and intra-individual variability which needs to be further explored. doi:10.1016/j.clinph.2016.10.333

P217 Disrupting cognitive control in dual-task situations by transcranial magnetic stimulation of the lateral prefrontal cortex—S. Kübler a, T. Schubert a,b (a Humboldt Universität zu Berlin, Institut für Psychologie, Berlin, Germany, b Martin-Luther-Universität Halle-Wittenberg, Halle, Germany) Introduction: Performance in dual-task situations is usually impaired compared to performance in single-task situations, which is reflected in prolonged reaction times as well as increased error rates. These dual-task costs can be explained by the requirement to recruit additional task-order control processes that are crucial for scheduling, monitoring and regulating the processing order of two temporally overlapping tasks. Recent neuroimaging studies with functional magnetic resonance imagery (fMRI) could show that the lateral prefrontal cortex (lPFC) may play an essential role for implementing these control processes. However, the association between prefrontal activity and task-order control remains only correlational due to the nature of the fMRI method. Objectives: The aim of this study was to provide evidence for the causal involvement of prefrontal activity in dual-task processing by applying transcranial magnetic stimulation (TMS). Methods: 16 Participants performed a dual-task consisting of two simple choice reaction tasks. Demands on task-order control processes were manipulated by introducing dual-task blocks with either fixed or random order of both tasks. We compared the effects of TMS over the lPFC to two control conditions. Results: As a result, we could show that in the stimulation condition dual-task performance decreased compared to control conditions only if demands on task-order control processes where high. Conclusion: This pattern of results supports the conclusion that the lPFC plays a causal role for the implementation of task-order control processes in situations with temporally overlapping tasks. More specifically, we argue that the lPFC is recruited for activating an internal order representation into working memory. doi:10.1016/j.clinph.2016.10.334

P218 Cerebellar involvement in facial emotion discrimination: A TMS study—V. Oldrati a,*, C. Ferrari b, Z. Cattaneo b, T. Vecchi a (a University of Pavia, Brain and Behavioral Sciences, Pavia, Italy, b University of Milano-Bicocca, Psychology, Milano, Italy) ⇑

Corresponding author.

The contribution of cerebellum to affective processing has been neglected for a long time. Recently, an increasing number of studies on both healthy participants and patients with cerebellar abnormalities pointed to a possible role of the cerebellum in the emotions regulation and perception. In this study, we aimed to investigate the involvement of the cerebellum in emotion discrimination by means of transcranial

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Abstracts / Clinical Neurophysiology 128 (2017) e1–e163

magnetic stimulation (TMS). We presented participants with pairs of faces with different emotional expressions (happy or angry) and we asked them to indicate whether the two faces showed the same or a different emotion. Triple-pulse TMS (20 Hz) was delivered between the first and the second face presentation over the left cerebellum, the primary visual cortex and the vertex (control site). Analyses suggest that cerebellar TMS impaired participants’ performance in emotion discrimination, in line with previous evidence on the link between cerebellum and emotional processing. doi:10.1016/j.clinph.2016.10.335

P219 The variability of targets for repetitive transcranial magnetic stimulation based on navigated TMS mapping and intrinsic connectivity measures—A. Poydasheva a,*, E. Zmeykina a, b a a A. Chernyavskiy , A. Chervyakov , N. Suponeva , M. Piradov a (a Research Center of Neurology, Neurorehabilitation and Physiotherapy, Moscow, Russian Federation, b Institute of Physics and Technology, Moscow, Russian Federation) ⇑

Corresponding author.

Introduction: Despite the quasi high effectiveness of the repetitive transcranial magnetic stimulation (rTMS) of left dorsolateral prefrontal cortex (lDLPFC) in treatment of major depression, the high effect size variability is noticed (Herbsman et al., 2009). One of the reasons for this variability is the imperfect targeting of stimulation point. Resting state functional MRI (rsfMRI) has become a very popular tool to measure an intrinsic connectivity. Seed-based connectivity analysis is the method to evaluate functional connectivity between a chosen region and the whole brain. This analysis could be used for rTMS point targeting (Fox et al., 2012). Objectives: Our aim was to evaluate the possibilities of seed-based connectivity analysis in TMS stimulation point targeting and to measure the variability of these points compared to navigated transcranial magnetic stimulation (nTMS)-guided targeting.

Materials and Methods: Five patients (all females, mean age = 36.6, SD = 8.7) suffering major depression were enrolled in this study. They were clinically evaluated with Beck Depression Inventory (mean value = 28.5, SD = 12). Resting-state fMRI data was acquired on 3T MR-scanner. nTMS with Abductor pollicis brevis muscle mapping was also performed with NBS eXimia Nexstim device. Maps of functional connectivity were built using CONNtoolbox for MATLAB. Subgenual cingulated cortex area (10 mm radius sphere at MNI coordinates (6,16,-10) was taken as a seed region. Then points in lDLPFC with maximum value of negative correlation were found individually in seed maps. The second pool of points was determined as5 cmanterior to individual APB muscle hotspot. The coordinates of two pools of points were compared inter- and intraindividually. Results: Maximal distance between nTMS-guided points was 13.27 mmvs.53.62 mm between rsfMRI-guided points. Mean distance to the center of points in nTMS-guided group was 5.45 mmvs 38.83 mmin rsfMRI-guided group. Mean distance between intraindividual nTMS- and rsfMRI-guided points was 40.02 mm (Fig. 1). Conclusion: The interindividual variability of rsfMRI-based points’ coordinates was much higher than in nTMS-based points. High intraindividual variability was also shown. We are starting a clinical trial comparing the effects of rTMS targeting with these two methods in major depression. doi:10.1016/j.clinph.2016.10.336

P220 Cortical time course of reading processing by navigated transcranial magnetic stimulation—M. Rogic´ Vidakovic´ a,*, A. ˇ ovic´ c, M. Zmajevic´ Schönwald d, Z. Dogaš a Jerkovic´ b, M. Perkušic´ C (a Laboratory for Human and Experimental Neurophysiology (LAHEN), Department of Neuroscience, School of Medicine, Split, Croatia , b University of Zagreb, Postgraduate Doctoral Studies of Psychology, Faculty of Philosophy, Zagreb, Croatia, c Translational Research in Biomedicine and Health TRIBE, Split, Croatia, d Clinical Medical Centre ‘‘Sisters of Mercy”, Department of Neurosurgery, Clinical Unit for Intraoperative Neurophysiologic Monitoring, Zagreb, Croatia) ⇑

Figure 1.

Corresponding author.

Introduction: The time scale at which reading processes operate is matter of intense debate. Chronometric TMS studies can be used to understand the global reading as well as temporal coordinates of sub processes involved in word reading. Objectives: The aim of our TMS study was to investigate timing of cortical areas involvement in process of reading words in healthy subjects. The study was designed to provide timing of activity in predefined cortical areas involved in reading aloud as a global process. Materials and Methods: Twelve healthy and right-handed volunteers (6 men, mean age 29.67 ± 9.82 years, and 6 females, mean age 28 5.8 years) underwent patterned protocol of rTMS over the specific brain areas related to reading process identified intraoperatiely, namely to: posterior part of superior temporal gyrus (PSTG), posterior part of middle temporal gyrus (PMTG), left supramarginal gyrus (SMG), angular gyrus (AnG), and posterior part of inferior frontal gyrus (opercular part of Broca’s area) (OpIFG), while participants were reading words (overt reading of presented words). Modified patterned rTMS stimulation protocol consisted of 4 bursts of 4 stimuli each, with an interstimulus interval of 6 ms, and a burst