title: Comparison between SI and SII responses as a function of stimulus intensity.
abstract: In this MEG study we investigated the differences in responses to somatosensory electrical stimuli between primary (SI) and secondary (SII) sensory cortices using 10 different levels of stimulus intensity, starting from below the sensory threshold up to a weak painful level. SI dipole source linearly increased in amplitude as the stimulus intensity raised up to a strong motor level and then saturated at higher stimulation levels. The contralateral and ipsilateral SII dipole source strengths followed the stimulus intensity growing up to the motor threshold, but showed a decrease at the strong motor level, followed by an increase as the stimulus intensity raised towards the weak painful threshold. These results suggest different responses of SI and SII cortices as the intensity of stimulation rises from non-painful to painful values.
authors: Institute of Advanced Biomedical Technologies, Department of Clinical Sciences, University of Chieti, via dei Vestini 33-66013, Chieti, Italy.
authors: Kathya
authors: K
authors: Torquati
authors: Vittorio
authors: V
authors: Pizzella
authors: Stefania
authors: S
authors: Della Penna
authors: Raffaella
authors: R
authors: Franciotti
authors: Claudio
authors: C
authors: Babiloni
authors: Paolo Maria
authors: PM
authors: Rossini
authors: Gian Luca
authors: GL
authors: Romani
mesh_terms: D000328:Adult; D000344:Afferent Pathways / Q000502:physiology*; D001931:Brain Mapping; D004558:Electric Stimulation; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008475:Median Nerve / Q000502:physiology*; D009431:Neural Conduction / Q000502:physiology; D009619:Nociceptors / Q000502:physiology; D010146:Pain / Q000473:pathology / Q000503:physiopathology*; D017288:Pain Threshold / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology*; D014110:Touch / Q000502:physiology*