title: High frequency repetitive sensory stimulation improves temporal discrimination in healthy subjects.
abstract: OBJECTIVE
  High frequency electrical stimulation of an area of skin on a finger improves two-point spatial discrimination in the stimulated area, likely depending on plastic changes in the somatosensory cortex. However, it is unknown whether improvement also applies to temporal discrimination.
  
  
  METHODS
  Twelve young and ten elderly volunteers underwent the stimulation protocol onto the palmar skin of the right index finger. Somatosensory temporal discrimination threshold (STDT) was evaluated before and immediately after stimulation as well as 2.5h and 24h later.
  
  
  RESULTS
  There was a significant reduction in somatosensory temporal threshold only on the stimulated finger. The effect was reversible, with STDT returning to the baseline values within 24h, and was smaller in the elderly than in the young participants.
  
  
  CONCLUSIONS
  High frequency stimulation of the skin focally improves temporal discrimination in the area of stimulation. Given previous suggestions that the perceptual effects rely on plastic changes in the somatosensory cortex, our results are consistent with the idea that the timing of sensory stimuli is, at least partially, encoded in the primary somatosensory cortex.
  
  
  CONCLUSIONS
  Such a protocol could potentially be used as a therapeutic intervention to ameliorate physiological decline in the elderly or in other disorders of sensorimotor integration.
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, United Kingdom; Dipartimento di Scienze Neurologiche e del Movimento, University of Verona, Verona, Italy. Electronic address: erro.roberto@gmail.com.
authors.forename: Roberto
authors.initials: R
authors.lastname: Erro
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, United Kingdom; Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Rocchi
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, United Kingdom; Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum, University of Bologna, Bologna, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Antelmi
authors.affiliation: Department of Primary Care and Public Health, Imperial College London, United Kingdom.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Palladino
authors.affiliation: Dipartimento di Scienze Neurologiche e del Movimento, University of Verona, Verona, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Tinazzi
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Rothwell
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, United Kingdom.
authors.forename: Kailash P
authors.initials: KP
authors.lastname: Bhatia
mesh_terms: D000328:Adult; D000368:Aged; D004192:Discrimination, Psychological / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D013003:Somatosensory Cortex / Q000502:physiology*; D013998:Time Perception / Q000502:physiology*
keywords: Coactivation; Dystonia; Plasticity; Repetitive sensory stimulation; Somatosensory temporal discrimination