Using optically-pumped magnetometers to measure magnetoencephalographic signals in the human cerebellum

Research output: Contribution to journalArticle

Authors

  • Tim M Tierney
  • Niall Holmes
  • Elena Boto
  • James Leggett
  • Sven Bestmann
  • Richard Bowtell
  • Matthew J Brookes
  • Gareth R Barnes

Colleges, School and Institutes

External organisations

  • Wellcome Centre for Human Neuroimaging, Queen Square Institute of Neurology, University College London, London, UK.
  • Department of Psychology, Peking University, Beijing, China ; School of Psychology, University of Birmingham, Birmingham, UK.
  • Sir Peter Mansfield Imaging Centre (SPMIC), School of Physics and Astronomy, University of Nottingham
  • Department of Clinical and Movement Neuroscience, Queen Square Institute of Neurology, University College London, London, UK.

Abstract

Key points: The application of conventional cryogenic magnetoencephalography (MEG) to the study of cerebellar functions is highly limited because typical cryogenic sensor arrays are far away from the cerebellum and naturalistic movement is not allowed in the recording. A new generation of MEG using optically pumped magnetometers (OPMs) that can be worn on the head during movement has opened up an opportunity to image the cerebellar electrophysiological activity non-invasively. We use OPMs to record human cerebellar MEG signals elicited by air-puff stimulation to the eye. We demonstrate robust responses in the cerebellum. OPMs pave the way for studying the neurophysiology of the human cerebellum. Abstract: We test the feasibility of an optically pumped magnetometer-based magnetoencephalographic (OP-MEG) system for the measurement of human cerebellar activity. This is to our knowledge the first study investigating the human cerebellar electrophysiology using optically pumped magnetometers. As a proof of principle, we use an air-puff stimulus to the eyeball in order to elicit cerebellar activity that is well characterized in non-human models. In three subjects, we observe an evoked component at approx. 50 ms post-stimulus, followed by a second component at approx. 85–115 ms post-stimulus. Source inversion localizes both components in the cerebellum, while control experiments exclude potential sources elsewhere. We also assess the induced oscillations, with time-frequency decompositions, and identify additional sources in the occipital lobe, a region expected to be active in our paradigm, and in the neck muscles. Neither of these contributes to the stimulus-evoked responses at 50–115 ms. We conclude that OP-MEG technology offers a promising way to advance the understanding of the information processing mechanisms in the human cerebellum.

Bibliographic note

© 2019 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Details

Original languageEnglish
Pages (from-to)4309-4324
Number of pages16
JournalThe Journal of Physiology
Volume597
Issue number16
Early online date25 Jun 2019
Publication statusPublished - 15 Aug 2019

Keywords

  • cerebellum, eyeblink conditioning, magnetoencephalography, optically pumped magnetometer

ASJC Scopus subject areas