Fig 4. Example trial from Experiment 2.

From the participant’s perspective, each trial began with the “alertness” signal of the white circle for 800ms. This was followed by a verb for 800ms, then a blank interval of 3500ms. The “go” signal of an exclamation mark was then presented for 1500ms. This was then followed by a blank screen for 2200ms, for a total trial length of 8800ms. Participants spoke the prefix+verb utterance when the “go” signal was presented. One TMS pulse would fire during each trial. This experiment had eight pulse timings– 400ms, 4100ms, 5180ms, 5260ms, 5340ms, 5420ms, 5500ms, 5580ms (each represented by the stimulation symbol)–as well as a null pulse condition.