How quickly we stop at a traffic light determines our survival. Similarly, how efficiently one can dodge a craving thought for a pint of beer could define one's relapse probability. Response inhibition, a form of impulsivity, measures one's ability to interrupt an ongoing action, and is central to neuropsychiatric disorders[1, 2]. Using cortico-cortical paired associative stimulation (cc-PAS) with transcranial magnetic (TMS) pulses, we targeted the right pre-supplementary motor area (preSMA) and right-inferior frontal cortex (rIFC). We previously showed an improvement in response inhibition as a function of age[3] using the stop-signal task[1]. Repeated pairs of pulses over two cortical regions induce changes in excitability and functional interaction due to spike time-dependent plasticity mechanisms[4]. Specifically, response inhibition improved in older individuals when the rIFC pulse preceded the preSMA pulse by 4milliseconds[3]. Here, we address the problem of reproducibility, a significant issue in TMS studies, by assessing the 4ms cc-PAS protocol in a different, larger group of healthy volunteers with a broader age range.