Probing the involvement of the primary somatosensory cortex in pain perception using high-definition transcranial direct current stimulation (HD-tDCS)


Investigators have suggested that innocuous somatosensory input is processed serially from the thalamus to the primary somatosensory cortex (S1) and then to other brain regions; whereas nociceptive input would project in parallel from the thalamus to S1 and other brain regions. Here, we test this hypothesis by assessing the effect of High-definition transcranial direct current stimulation (HD-tDCS) applied to the left S1 on the perception and event-related potentials (ERPs) elicited by nociceptive and non-nociceptive stimuli delivered to the ipsilateral and contralateral hand. HD-tDCS was achieved using a cathode surrounded by four anodes (20 minutes; 1 mA). Nociceptive stimuli were pulses of radiant heat delivered to the hand dorsum. Non-nociceptive stimuli were short-lasting vibrations delivered to the index. Nociceptive and non-nociceptive ERPs were recorded immediately before and after HD-tDCS. After each stimulus, participants rated intensity of perception. Because HD-tDCS was expected to reduce the excitability of the left S1, we expected that the responses to non-nociceptive stimulation of the contralateral hand would be reduced as compared to the ipsilateral hand. Furthermore, we predicted that the responses to nociceptive stimulation of the contralateral hand would show a similar reduction if and only if S1 constitutes an obligatory relay for nociceptive input.

9th Pain in Europe (EFIC) Congress
Gan Huang
Gan Huang

My research interests include Neural Modulation, Brain Computer Interface and Neural Prosthetics.