Direction-specific cortical response immediately after moving tactile stimuli in female humans

This study looked for a direction-specific cortical response immediately after application of moving tactile stimuli in healthy female humans. Four pairs of stimulus electrodes were placed over the left index finger pulp on the distal-proximal axis. Four times, once in every 40 ms interval, an electrical stimulus to the finger pulp was delivered through one of the four pairs of electrodes; each time the stimulus site changed in order to induce a sensation of tactile motion. The slope of the electroencephalographic trace, as recorded from electrodes placed over the CP, P4 and right hMT+/V5 in the period 150-200 ms after the onset of stimuli delivered in sequence from the distal to proximal site, was significantly different from that after stimuli delivered in sequence from the proximal to distal site. The cortical response immediately after the proximally-directed moving tactile stimuli was different from that after the distally-directed moving tactile stimuli in the hemisphere contralateral to the stimulus side.