The primary somatosensory cortex largely contributes to the early part of the cortical response elicited by nociceptive stimuli

► We used 64-channel EEG in 35 subjects to investigate the earliest LEP sources. ► The earliest hand-LEP topography is maximal over contralateral central electrodes. ► The earliest foot-LEP topography is maximal over the midline central electrodes. ► These topographies are compatible with a generator in S1. ► Hand and foot areas of S1 generate the largest part of the earliest LEP response.