title: Understanding the link between somatosensory temporal discrimination and movement execution in healthy subjects.
abstract: The somatosensory temporal discrimination threshold (STDT) is the shortest interval at which an individual recognizes paired stimuli as separate in time. We investigated whether and how voluntary movement modulates STDT in healthy subjects. In 17 healthy participants, we tested STDT during voluntary index-finger abductions at several time-points after movement onset and during motor preparation. We then tested whether voluntary movement-induced STDT changes were specific for the body segment moved, depended on movement kinematics, on the type of movement or on the intensity for delivering paired electrical stimuli for STDT To understand the mechanisms underlying STDT modulation, we also tested STDT during motor imagery and after delivering repetitive transcranial magnetic stimulation to elicit excitability changes in the primary somatosensory cortex (S1). When tested on the moving hand at movement onset and up to 200 msec thereafter, STDT values increased from baseline, but during motor preparation remained unchanged. STDT values changed significantly during fast and slow index-finger movements and also, though less, during passive index-finger abductions, whereas during tonic index-finger abductions they remained unchanged. STDT also remained unchanged when tested in body parts other than those engaged in movement and during imagined movement. Nor did testing STDT at increased intensity influence movement-induced STDT changes. The cTBS-induced S1 cortical changes left movement-induced STDT changes unaffected. Our findings suggest that movement execution in healthy subjects may alter STDT processing.
authors.affiliation: IRCCS Neuromed, Pozzilli (IS), Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Conte
authors.affiliation: IRCCS Neuromed, Pozzilli (IS), Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Belvisi
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University Rome, Rome, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Manzo
authors.affiliation: IRCCS Neuromed, Pozzilli (IS), Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bologna
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University Rome, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Barone
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University Rome, Rome, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Tartaglia
authors.affiliation: Department of Neurology and Psychiatry, Sapienza University Rome, Rome, Italy.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Upadhyay
authors.affiliation: IRCCS Neuromed, Pozzilli (IS), Italy Department of Neurology and Psychiatry, Sapienza University Rome, Rome, Italy alfredo.berardelli@uniroma1.it.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Berardelli
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006225:Hand / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D009068:Movement; D013003:Somatosensory Cortex / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
keywords: Movement execution; sensory gating; sensory temporal discrimination