PT  - JOURNAL ARTICLE
AU  - Robert Guggenberger
AU  - Maximilian Scherer
AU  - Alireza Gharabaghi
TI  - Risks in signal processing pipelines influencing the estimation of phase dependency for EEG-TMS
AID  - 10.1101/477166
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 477166
4099  - http://biorxiv.org/content/early/2018/11/30/477166.short
4100  - http://biorxiv.org/content/early/2018/11/30/477166.full
AB  - Phase-dependency of cortico-spinal excitability can be researched using TMS-EEG. Due to the large artifact, non-causal filters can smear the TMS artifact and distort the phase. However, causal filters can become biased by too high filter orders or uneven pass-bands. We explored the influence of different signal processing pipelines on the estimation of the optimal phase. This exploration involved performing two simulation studies. In the first, we simulated two different phase-dependencies (uni-versus bimodal) and sought to recover them with two distinct approaches that have previously been described. In the second, we specifically explored how filter parameters (e.g., order, pass-band) biased the phase estimation. On the basis of these findings, we propose using up-to-date toolboxes, re-running scripts after software updates and performing simulation studies in parallel to safeguard the analysis pipeline of empirical studies.M.S. was supported by the Graduate Training Centre of Neuroscience & International Max Planck Research School, Graduate School of Neural Information Processing, Tuebingen, Germany. A.G. was supported by grants from the German Federal Ministry of Education and Research [BMBF 13GW0119B, IMONAS; 13GW0214B, INSPIRATION; 13GW0270B, INAUDITAS] and the Baden-Wuerttemberg Foundation [NEU005, NemoPlast]. The authors declare no competing financial interests.