Using optically-pumped magnetometers to measure magnetoencephalographic signals in the human cerebellum
AbstractWe test the feasibility of an optically pumped magnetometer-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 OPMs. As a proof of principle, we use an air-puff stimulus to the eyeball in order to elicit cerebellar activity that is well characterised in non-human models. In three subjects, we observe an evoked component at approx. 50ms post-stimulus, followed by a second component at approx. 85-115 ms post-stimulus. Source inversion localises both components in the cerebellum, while control experiments exclude potential sources elsewhere. We also assess the induced oscillations, with time-frequency decompositions, and identify the source in the occipital lobe, a region expected to be active in our paradigm. We conclude that the OP-MEG technology offers a promising way to advance the understanding of the information processing mechanisms in the human cerebellum.