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P226 Effects of transcranial static magnetic field stimulation of the visual cortex on experimental photophobia
Abstracts / Clinical Neurophysiology 128 (2017) e1–e163
United States, b Oakland University, William Beaumont School of Medicine, Rochester, MI, United States, c University of Florida, Gainesville, FL, United States, d INSERM, U1127, Paris, France) ⇑
Corresponding author.
Introduction: Voluntary actions are characterized by a feeling that the self is the cause of action (sense of agency, SoA). SoA is created from efferent indicators (action prediction, body scheme) and afferent indicators (visual feedback, proprioception). In case of congruency between indicators, experience of SoA develops; in case of incongruence, the action is experienced as strange and non-self. Several areas have been identified by meta-analyses (Syfnozik et al., 2008; Sperduti et al, 2011) as potentially important for the generation of SoA. Objectives: Here we tested to what extent the pre-supplementary motor area (pSMA) and the right and left angular gyri (RAG, LAG) are involved in the SoA as assessed by ‘‘temporal binding” (TB1) (Haggard et al., 2002). Patients and methods: Nineteen healthy, right-handed volunteers were enrolled, and randomly distributed in 3 groups of 10 subjects each. Each group had to estimate the time delay between a movement and a subsequent sound in a test battery before and after 20 min of 1 Hz rTMS (targeting 1 area/group). The test battery consisted of 2 conditions: (VOL) the movement was a self-paced wrist extension and (EXP) the movement was a passive extension of the wrist, pulled up by the experimenter. Each movement triggered a sound via an accelerometer taped to the moving hand. Unknown to the subject, each movement-sound delay was randomly chosen delay of 100, 400, 700, or 1000 ms; however, the subjects were instructed to give their best guess on a continuous time-scale. The rTMS was applied over one of the 3 areas of interest under individualized MRI-guided neuronavigation for 1200 pulses at 110% resting motor threshold. Results: At baseline, we found TB at shorter delays, i.e., delays were estimated 50 ms shorter in VOL than in EXP for 100 and 400 ms. TB was eliminated by rTMS of pSMA. Conclusion: Pre-SMA and LAG are involved in agency, but in different ways: pSMA when incongruence between indicators is maximal and LAG when congruence is maximal. It might be that pSMA is more involved in SoA perception, while LAG is more related to SoA buid-up by matching the feedforward and feedback.
e125
References Haggard et al. Nat Neurosci 2002. Syfnozik et al. Coscious Cogn 2008. Sperduti et al. Brain Struct Funct 2011. doi:10.1016/j.clinph.2016.10.342
P226 Effects of transcranial static magnetic field stimulation of the visual cortex on experimental photophobia—V. Soto-Leon, E. Lozano Soto, S. Sabbarese, B.A. Strange, G. Foffani, A. Oliviero * (Hospital Nacional de Parapléjicos, FENNSI Group, Toledo, Spain) ⇑
Corresponding author.
Transcranial static magnetic field stimulation (tSMS) in humans reduces cortical excitability. The objective of this study was to determine if tSMS was effective in reducing experimental photophobia. We performed a sham-controlled crossover study. tSMS (or sham) was applied for 10 min with a cylindric magnet on the occiput of 20 healthy subjects. We assessed subjective discomfort induced by a blue-light with two different intensity presented in a dark room. Discomfort was rated from 0 to 10. After few minutes of applications the tSMS reduced the discomfort induced by a blue-light with high intensity. Our data indicate that the application of tSMS can be used to reduce the discomfort caused by experimental photophobia. doi:10.1016/j.clinph.2016.10.343
P227 TMS-induced modulation of Default-Mode Network regional neurochemistry relates to functional connectivity, brain structure and cognition in healthy aging—K. Abellaneda-Pérez a, E. Solana b, D. Vidal-Piñeiro c, N. Bargalló d,e, S. Domènech f, A. Salvà f, J. Valls-Solé g, M.- F. Kuo h,i,j, M.A. Nitsche h,i,j, A. Pascual-Leone k,l, D. Bartrés-Faz a,b,* (a University of Barcelona, Department of Medicine, Barcelona, Spain , b Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Spain, c University of Oslo, Department of Psychology, Oslo, Norway , d Hospital Clínic
United States, b Oakland University, William Beaumont School of Medicine, Rochester, MI, United States, c University of Florida, Gainesville, FL, United States, d INSERM, U1127, Paris, France) ⇑
Corresponding author.
Introduction: Voluntary actions are characterized by a feeling that the self is the cause of action (sense of agency, SoA). SoA is created from efferent indicators (action prediction, body scheme) and afferent indicators (visual feedback, proprioception). In case of congruency between indicators, experience of SoA develops; in case of incongruence, the action is experienced as strange and non-self. Several areas have been identified by meta-analyses (Syfnozik et al., 2008; Sperduti et al, 2011) as potentially important for the generation of SoA. Objectives: Here we tested to what extent the pre-supplementary motor area (pSMA) and the right and left angular gyri (RAG, LAG) are involved in the SoA as assessed by ‘‘temporal binding” (TB1) (Haggard et al., 2002). Patients and methods: Nineteen healthy, right-handed volunteers were enrolled, and randomly distributed in 3 groups of 10 subjects each. Each group had to estimate the time delay between a movement and a subsequent sound in a test battery before and after 20 min of 1 Hz rTMS (targeting 1 area/group). The test battery consisted of 2 conditions: (VOL) the movement was a self-paced wrist extension and (EXP) the movement was a passive extension of the wrist, pulled up by the experimenter. Each movement triggered a sound via an accelerometer taped to the moving hand. Unknown to the subject, each movement-sound delay was randomly chosen delay of 100, 400, 700, or 1000 ms; however, the subjects were instructed to give their best guess on a continuous time-scale. The rTMS was applied over one of the 3 areas of interest under individualized MRI-guided neuronavigation for 1200 pulses at 110% resting motor threshold. Results: At baseline, we found TB at shorter delays, i.e., delays were estimated 50 ms shorter in VOL than in EXP for 100 and 400 ms. TB was eliminated by rTMS of pSMA. Conclusion: Pre-SMA and LAG are involved in agency, but in different ways: pSMA when incongruence between indicators is maximal and LAG when congruence is maximal. It might be that pSMA is more involved in SoA perception, while LAG is more related to SoA buid-up by matching the feedforward and feedback.
e125
References Haggard et al. Nat Neurosci 2002. Syfnozik et al. Coscious Cogn 2008. Sperduti et al. Brain Struct Funct 2011. doi:10.1016/j.clinph.2016.10.342
P226 Effects of transcranial static magnetic field stimulation of the visual cortex on experimental photophobia—V. Soto-Leon, E. Lozano Soto, S. Sabbarese, B.A. Strange, G. Foffani, A. Oliviero * (Hospital Nacional de Parapléjicos, FENNSI Group, Toledo, Spain) ⇑
Corresponding author.
Transcranial static magnetic field stimulation (tSMS) in humans reduces cortical excitability. The objective of this study was to determine if tSMS was effective in reducing experimental photophobia. We performed a sham-controlled crossover study. tSMS (or sham) was applied for 10 min with a cylindric magnet on the occiput of 20 healthy subjects. We assessed subjective discomfort induced by a blue-light with two different intensity presented in a dark room. Discomfort was rated from 0 to 10. After few minutes of applications the tSMS reduced the discomfort induced by a blue-light with high intensity. Our data indicate that the application of tSMS can be used to reduce the discomfort caused by experimental photophobia. doi:10.1016/j.clinph.2016.10.343
P227 TMS-induced modulation of Default-Mode Network regional neurochemistry relates to functional connectivity, brain structure and cognition in healthy aging—K. Abellaneda-Pérez a, E. Solana b, D. Vidal-Piñeiro c, N. Bargalló d,e, S. Domènech f, A. Salvà f, J. Valls-Solé g, M.- F. Kuo h,i,j, M.A. Nitsche h,i,j, A. Pascual-Leone k,l, D. Bartrés-Faz a,b,* (a University of Barcelona, Department of Medicine, Barcelona, Spain , b Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Spain, c University of Oslo, Department of Psychology, Oslo, Norway , d Hospital Clínic