Detection and Removal of Hyper-synchronous Artifacts in Massively Parallel Spike Recordings
- Jonas Oberste-Frielinghaus1,2,
- Aitor Morales-Gregorio1,3,
- Simon Essink1,2,
- Alexander Kleinjohann1,2,
- Cristiano A. Köhler1,2,
- Frederic Barthélemy1,
- Alexa Riehle4,
- Thomas Brochier4,
- Simon Musall5,6,7,
- Junji Ito1 and
- Sonja Grün1,8,9
- 1Institute for Advanced Simulation (IAS-6), Jülich Research Centre, Jülich 52425, Germany
- 2RWTH Aachen University, Aachen 52062, Germany
- 3Faculty of Mathematics and Physics, Charles University, Prague 12116, Czechia
- 4Institut de Neurosciences de la Timone (INT), Aix-Marseille Université, CNRS, Marseille 13005, France
- 5Institute of Biological Information Processing (IBI-3), Jülich Research Centre, Jülich 52425, Germany
- 6Institute of Biology 2, RWTH Aachen University, Aachen 52074, Germany
- 7Faculty of Medicine, Institute of Experimental Epileptology and Cognition Research, University of Bonn, Bonn 53127, Germany
- 8JARA Brain Institute I (INM-10), Jülich Research Centre, Jülich 52425, Germany
- 9Theoretical Systems Neurobiology, RWTH Aachen University, Aachen 52056, Germany
- Correspondence should be addressed to Jonas Oberste-Frielinghaus at j.oberste-frielinghaus{at}fz-juelich.de.
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Author Contributions: J.O.-F., J.I., and S.G. designed research; J.O.-F., A.M.-G., A.K., C.A.K., F.B., A.R., T.B., S.M., J.I., and S.G. performed research; J.O.-F., A.M.-G., S.E., A.K., F.B., and J.I. analyzed data; J.O.-F., A.M.-G., S.E., A.K., C.A.K., F.B., A.R., T.B., S.M., J.I., and S.G. wrote the first draft of the paper; J.O.-F., A.M.-G., S.E., A.K., C.A.K., F.B., A.R., T.B., S.M., J.I., and S.G. edited the paper; J.O.-F., A.M.-G., S.E., A.K., C.A.K., F.B., A.R., T.B., S.M., J.I., and S.G. wrote the paper.
Abstract
Contemporary electrophysiology experiments often involve massively parallel recordings of neuronal activity using multi-electrode arrays. While researchers have been aware of artifacts arising from electric cross-talk between channels in setups for such recordings, systematic and quantitative assessment of the effects of those artifacts on the data quality has never been reported. Here we present, based on examination of electrophysiology recordings from multiple laboratories, that multi-electrode recordings of spiking activity commonly contain extremely precise (at the data sampling resolution) spike coincidences far above the chance level. The recordings analyzed here were obtained from two rhesus macaques (Macaca mulatta; one male, one female) and one male mouse (C57BL/6J). We derive, through modeling of the electric cross-talk, a systematic relation between the amount of such hyper-synchronous events (HSEs) in channel pairs and the correlation between the raw signals of those channels in the multi-unit activity frequency range (500–7,500 Hz). We show that whitening the band-pass filtered raw signals removes the above chance HSEs; strongly suggesting they originate from linear mixing of signals. Whitening should therefore be performed prior to spike sorting and any further analysis of precise spike correlation, otherwise analysis results may be considerably affected.
Footnotes
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We thank Julia Sprenger, Vahid Rostami and Emiliano Torre for previous work on artifacts. This project has received funding partly from the European Union’s Horizon 2020 Framework Programme for Research and Innovation under Specific Grant Agreement No. 945539 (Human Brain Project SGA3), the NRW-network “iBehave” (grant number: NW21-049), and by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—368482240/GRK2416, the DFG Priority Program (SPP 2041 “Computational Connectomics”) [S.J. van Albada: AL 2041/1-1] and International Research Project (IRP) “Vision-For-Action” between CNRS, Aix-Marseille University and Forschungszentrum Jülich. This work received funding from the Programme Johannes Amos Comenius (OP JAK) under the project “MSCA Fellowships CZ - UK3” (registration number CZ.02.01.01/00/22 010/0008220).
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The authors declare no competing financial interests.
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This paper contains supplemental material available at: https://doi.org/10.1523/JNEUROSCI.0295-26.2026
- Received February 18, 2026.
- Revision received June 19, 2026.
- Accepted July 13, 2026.
- Copyright © 2026 Oberste-Frielinghaus et al.
This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license, which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
