UC Santa Barbara

Functional imaging studies have revealed the default mode network (DMN) activates when people are at rest. However, generally only minimal instructions were provided among those studies. Our goal in this study was to demonstrate how resting state activity varies with the knowledge of being watched. In this study, we used two distinct manipulations to address this question: first, we described two separate scans as being either anatomical or functional (with little additional detail), when in fact both were functional; and second, in a putatively separate experiment, we informed participants we were able to observe their thoughts, and after a more thorough description, carried out three more functional scans, one of which was again described as anatomical. Our results demonstrate there are systematic differences across several networks as a function of instructional differences. Most strikingly, there was a significant increase in the orbitofrontal cortex (OFC) when comparing the first functional scan to the first sham anatomical scan, and a substantial increase in functional connectivity within the DMN when comparing the second sham anatomical scan to the second and third functional scans. These results suggest the mere awareness that one is being watched causes significant changes in the patterns of activity across functional networks, including the DMN. They also suggest the importance of using precise instructions in resting-state studies, because even slight variations in instruction can have substantial impacts on the brain's activity at rest.