title: MEG reveals different contributions of somatomotor cortex and cerebellum to simple reaction time after temporally structured cues.
abstract: Magnetoencephalography (MEG) was used to measure brain activity while participants performed a simple reaction to targets after either a random interval (uncued targets) or a series of isochronous warning stimuli with 200-ms intervals that acted as a countdown. Targets could arrive "on time" or "early" relative to the preceding warning stimuli. Cerebellar activity before any stimulus onset predicted uncued simple reaction time. Onset of activity in somatomotor cortex relative to the target predicted reaction time after two warning stimuli when the target arrived on time or early. After three warning stimuli, when the target arrived on time and was certain to occur, prestimulus cerebellar activity and somatomotor onset were significant predictors of reaction time. When the target arrived early after three warning stimuli, prestimulus cerebellar and cingulate activity were predictive. The cerebellar results may reflect a number of possible factors, including a role in timing, response readiness, prediction and attention.
authors.affiliation: Department of Psychology, University of New Mexico, Albuquerque, New Mexico 87131, USA. tma2010@yahoo.com
authors.forename: Tim
authors.initials: T
authors.lastname: Martin
authors.forename: Jon M
authors.initials: JM
authors.lastname: Houck
authors.forename: Joel Pearson
authors.initials: JP
authors.lastname: Bish
authors.forename: Dubravko
authors.initials: D
authors.lastname: Kicić
authors.forename: C Chad
authors.initials: CC
authors.lastname: Woodruff
authors.forename: Sandra N
authors.initials: SN
authors.lastname: Moses
authors.forename: Dustin C
authors.initials: DC
authors.lastname: Lee
authors.forename: Claudia D
authors.initials: CD
authors.lastname: Tesche
mesh_terms: D000161:Acoustic Stimulation; D001288:Attention / Q000502:physiology*; D001303:Auditory Cortex / Q000033:anatomy & histology / Q000502:physiology; D001307:Auditory Perception / Q000502:physiology; D001931:Brain Mapping; D002531:Cerebellum / Q000033:anatomy & histology / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003463:Cues; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009044:Motor Cortex / Q000033:anatomy & histology / Q000502:physiology*; D009415:Nerve Net / Q000033:anatomy & histology / Q000502:physiology; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology*; D013003:Somatosensory Cortex / Q000033:anatomy & histology / Q000502:physiology*; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology