title: Early contingent negative variation (CNV) shows a small symmetrical negativity in a somatosensory paradigm.
abstract: The influence of sensory modulation on the early stage of information processing was investigated with a somatosensory contingent negative variation (CNV) paradigm. Whether or not even a somatosensory input as well as auditory or visual stimulus to one hemisphere elicits the symmetrical "early CNV" was also examined. Eleven normal individuals (3 males, 8 females) performed a conventional CNV paradigm with a click sound as the warning stimulus (WS) and a red light flash as the imperative stimulus (IS). Nine individuals (5 males, 4 females) did the somatosensory CNV paradigm with paired electrical stimuli as WS and IS. The subjects were instructed to press a button in response to IS as fast as possible. The early CNV amplitude was smaller and P300 latency was longer in somatosensory paradigm than conventional paradigm. In addition, the latency of P100 in a somatosensory paradigm was longer than that of N100 in a conventional paradigm. These findings suggest that the initiation of early detection, reflected by P100, the initiation of cognition, reflected by P300, and orienting response, reflected by early CNV, are delayed in a somatosensory CNV paradigm. Furthermore, all event-related potentials (ERPs) evoked by somatosensory stimuli showed a bilateral symmetry.
authors.affiliation: Department of Neuropsychiatry, Hirosaki University School of Medicine, Hirosaki, Japan. y-sato-m@oodate.or.jp
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Sato
authors.forename: Hirooki
authors.initials: H
authors.lastname: Yabe
authors.forename: Tomiharu
authors.initials: T
authors.lastname: Hiruma
authors.forename: Takeyuki
authors.initials: T
authors.lastname: Sutoh
authors.forename: Naoko
authors.initials: N
authors.lastname: Shinozaki
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Nashida
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsuoka
authors.forename: Sunao
authors.initials: S
authors.lastname: Kaneko
mesh_terms: D000328:Adult; D003071:Cognition / Q000502:physiology*; D003265:Contingent Negative Variation / Q000502:physiology*; D004558:Electric Stimulation; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity