Sometimes noise is the signal“What happened is that we began putting people in scanners that can measure their brain activity,” Buckner recalls now, “and Mother Nature shouted back at us.” When people were told to sit and do nothing, the PET scans showed a distinct surge of mental energy in some regions. The resting state turned out to be more active than the active state. The odd blast of activity during the resting state would be observed in dozens of other studies using a similar control structure during this period. To this first generation of scientists using PET scans, the active rest state was viewed, in Buckner’s words, as “a confound, as troublesome.” A confound is an errant variable that prevents a scientist from doing a proper control study. It’s noise, mere interference getting in the way of the signal that science is looking for. Buckner and his colleagues noted the strange activity in a paper submitted in 1993, but almost as an afterthought, or an apology.