title: Sequential roles of primary somatosensory cortex and posterior parietal cortex in tactile-visual cross-modal working memory: a single-pulse transcranial magnetic stimulation (spTMS) study.
abstract: BACKGROUND
  Both monkey neurophysiological and human EEG studies have shown that association cortices, as well as primary sensory cortical areas, play an essential role in sequential neural processes underlying cross-modal working memory.
  
  
  OBJECTIVE
  The present study aims to further examine causal and sequential roles of the primary sensory cortex and association cortex in cross-modal working memory.
  
  
  METHODS
  Individual MRI-based single-pulse transcranial magnetic stimulation (spTMS) was applied to bilateral primary somatosensory cortices (SI) and the contralateral posterior parietal cortex (PPC), while participants were performing a tactile-visual cross-modal delayed matching-to-sample task. Time points of spTMS were 300 ms, 600 ms, 900 ms after the onset of the tactile sample stimulus in the task.
  
  
  RESULTS
  The accuracy of task performance and reaction time were significantly impaired when spTMS was applied to the contralateral SI at 300 ms. Significant impairment on performance accuracy was also observed when the contralateral PPC was stimulated at 600 ms.
  
  
  CONCLUSIONS
  SI and PPC play sequential and distinct roles in neural processes of cross-modal associations and working memory.
authors.affiliation: The Key Lab of Brain Functional Genomics, MOE & STCSM, Institute of Cognitive Neuroscience, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China. Electronic address: yixuanku@gmail.com.
authors.forename: Yixuan
authors.initials: Y
authors.lastname: Ku
authors.affiliation: The Key Lab of Brain Functional Genomics, MOE & STCSM, Institute of Cognitive Neuroscience, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China.
authors.forename: Di
authors.initials: D
authors.lastname: Zhao
authors.affiliation: The Key Lab of Brain Functional Genomics, MOE & STCSM, Institute of Cognitive Neuroscience, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Hao
authors.affiliation: The Key Lab of Brain Functional Genomics, MOE & STCSM, Institute of Cognitive Neuroscience, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Hu
authors.affiliation: MIND Research Institute, Irvine, CA, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Bodner
authors.affiliation: Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA; NYU-ECNU Institute of Brain and Cognitive Science, NYU Shanghai, Shanghai, China. Electronic address: yzhou12@jhmi.edu.
authors.forename: Yong-Di
authors.initials: YD
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*; D014110:Touch / Q000502:physiology; D055698:Touch Perception / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Cross-modal; Primary somatosensory cortex; Working memory; spTMS