Brain Topography

, Volume 22, Issue 1, pp 18–23

Saccade Related Gamma-Band Activity in Intracerebral EEG: Dissociating Neural from Ocular Muscle Activity

  • Karim Jerbi
  • Samson Freyermuth
  • Sarang Dalal
  • Philippe Kahane
  • Olivier Bertrand
  • Alain Berthoz
  • Jean-Philippe Lachaux
Original Paper

DOI: 10.1007/s10548-009-0078-5

Cite this article as:
Jerbi, K., Freyermuth, S., Dalal, S. et al. Brain Topogr (2009) 22: 18. doi:10.1007/s10548-009-0078-5

Abstract

Recent evidence suggests that transient increases in scalp electroencephalography (EEG) gamma band power (above 30 Hz) can be due to miniature eye movements. Although, these findings do not raise doubts about the widely established role of gamma range neural synchrony, it does call for caution when it comes to interpreting high frequency scalp EEG data. By contrast, gamma-band activity detected with intracerebral EEG (iEEG) is assumed to be immune to such miniature saccade artefacts. Here, we show for the first time, that while this is indeed largely the case, intracerebral recordings in the temporal pole of implanted patients can be contaminated by saccadic eye muscle artefacts resulting in typical high gamma-band power increases. By analyzing data from multiple depth electrodes, we show that this artefact is confined to the pole of the temporal lobe because of its immediate vicinity to extraocular muscles (rectus lateralis). For other brain structures, our analysis shows that the use of stereotactic EEG with a bipolar montage provides a robust and convenient tool to explore the functional role of gamma synchronization in humans with high anatomical accuracy during a wide range of cognitive processes, including oculomotor behaviour.

Keywords

Intracerebral EEG Presaccadic spike potential Gamma band activity Reading Temporal pole Artefact Saccades Scalp EEG Stereotactic EEG Eye movements 

Supplementary material

10548_2009_78_MOESM1_ESM.doc (43 kb)
Supplementary material 1 (DOC 43 kb)
10548_2009_78_MOESM2_ESM.tif (33.7 mb)
Supplementary material 2 (TIFF 34458 kb)

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Karim Jerbi
    • 1
    • 2
    • 3
  • Samson Freyermuth
    • 3
  • Sarang Dalal
    • 1
    • 2
  • Philippe Kahane
    • 4
    • 5
  • Olivier Bertrand
    • 1
    • 2
  • Alain Berthoz
    • 3
  • Jean-Philippe Lachaux
    • 1
    • 2
  1. 1.Brain Dynamics and CognitionINSERM U821LyonFrance
  2. 2.Université Claude Bernard Lyon 1LyonFrance
  3. 3.Laboratoire de Physiologie de la Perception et de l’ActionParisFrance
  4. 4.Department of Neurology and GIN U836 INSERM-UJF-CEA Research UnitGrenoble HospitalGrenobleFrance
  5. 5.CTRS-IDEE, University HospitalLyonFrance

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