Low-frequency rTMS stimulation over superior parietal cortex medially improves time reproduction and increases the right dorsolateral prefrontal cortex predominance.

Aim Of The Study: Previous studies have shown that several cortical regions are involved in temporal tasks in multiple timescales. However, the hemispheric predominance of the dorsolateral prefrontal cortex (DLPFC) during time reproduction after repetitive low-frequency transcranial magnetic stimulation (rTMS) is relatively unexplored. Here, we study the effects of 1 Hz rTMS and sham stimulation applied medially over the superior parietal cortex (SPC) on the DLPFC alpha and beta band asymmetry and on time reproduction.

Materials And Methods: For this purpose, we have combined rTMS with electroencephalography in 20 healthy subjects who performed the time reproduction task in two conditions (sham and 1 Hz).

Results: The worst performance was observed in sham and 1Hz conditions for longer time intervals (p < .05), with the 1Hz condition subjects sub-reproducing the time interval, closer to the target interval (p < .05). The right DLPFC hemispheric predominance was found in both conditions, but after low-frequency rTMS, the right hemisphere predominance increased in the 1Hz condition (p < .05).

Conclusions: Results of this study suggest that rTMS applied over the SPC influences time interval interpretation and the DLPFC functions. Future studies would explore the effects of the rTMS application to other cortical areas, and study how it influences time interval interpretation.