Temporal window of integration in the somatosensory modality: An MEG study

Abstract

Objective We sought to clarify the presence of a temporal window of integration (TWI) in the somatosensory modality by manipulating the inter-stimulus interval (ISI). Methods We recorded cortical activity following the last of a train of electric pulses (stimulus offset) applied to the left hand in nine healthy volunteers using magnetoencephalography (MEG). Somatosensory evoked magnetic fields (SEFs) were elicited by the offset of a train of pulses 3 s in total duration with four ISIs (25, 50, 75, and 100 ms). Results Results show that (i) off-M100 was clearly elicited by the ISI-25 and 50 ms conditions but not ISI-75 and 100 ms conditions, and (ii) the generator for off-M100 was mainly located in the contralateral primary and secondary somatosensory cortex (SI and SII). Conclusion The upper limit of the TWI in the somatosensory modality is between 50 and 75 ms, and the contralateral SI and SII play an important role in integrating temporal information. Significance The present study clarifies the presence of the TWI in the somatosensory modality.