title: Microsaccade control signals in the cerebellum.
abstract: Microsaccades, the small saccades made when we try to keep the eyes still, were once believed to be inconsequential for vision, but recent studies suggest that they can precisely relocate gaze to tiny visual targets. Because the cerebellum is necessary for motor precision, we investigated whether microsaccades may exploit this neural machinery in monkeys. Almost all vermal Purkinje cells, which provide the eye-related output of the cerebellar cortex, were found to increase or decrease their simple spike firing rate during microsaccades. At both the single-cell and population level, microsaccade-related activity was highly similar to macrosaccade-related activity and we observed a continuous representation of saccade amplitude that spanned both the macrosaccade and microsaccade domains. Our results suggest that the cerebellum's role in fine-tuning eye movements extends even to the oculomotor system's smallest saccades and add to a growing list of observations that call into question the classical categorical distinction between microsaccades and macrosaccades.
authors.affiliation: Department of Cognitive Neurology, Hertie Institute for Clinical Brain Research, Tübingen 72076, Germany; and Graduate School of Neural and Behavioural Sciences, University of Tübingen, Tübingen 72074, Germany.
authors.forename: Daniel
authors.identifier: http://orcid.org/0000-0002-6042-2817
authors.initials: D
authors.lastname: Arnstein
authors.affiliation: Department of Cognitive Neurology, Hertie Institute for Clinical Brain Research, Tübingen 72076, Germany; and Graduate School of Neural and Behavioural Sciences, University of Tübingen, Tübingen 72074, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Junker
authors.affiliation: Department of Cognitive Neurology, Hertie Institute for Clinical Brain Research, Tübingen 72076, Germany; and Graduate School of Neural and Behavioural Sciences, University of Tübingen, Tübingen 72074, Germany.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Smilgin
authors.affiliation: Department of Cognitive Neurology, Hertie Institute for Clinical Brain Research, Tübingen 72076, Germany; and.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Dicke
authors.affiliation: Department of Cognitive Neurology, Hertie Institute for Clinical Brain Research, Tübingen 72076, Germany; and thier@uni-tuebingen.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Thier
mesh_terms: D000818:Animals; D008253:Macaca mulatta; D008297:Male; D011689:Purkinje Cells / Q000502:physiology*; D012438:Saccades
keywords: Purkinje cells; cerebellum; fixational eye movements; microsaccades; oculomotor