Errors in the performance of repetitive or “boring” tasks—often attributed to a momentary lapse in concentration—can be serious in such activities as flying a passenger aircraft. Is there any method that would provide warning of such lapses—for example by monitoring brain activity? Researchers scanned the brains of volunteers performing a repetitive task. When the tasks were being performed correctly, the volunteers’ brains showed activity in cognitive-processing regions. However, these regions became less active several seconds before some errors were made, and another brain region, region X, became active. The researchers concluded that the monitoring of region X could provide warning of an impending error.

Which of the following, if true, most supports the researchers’ conclusion?