Are attention and cognitive control altered by fMRI scanner environment? Evidence from Go/No-go tasks in ADHD.

It is widely assumed that cognitive processes studied in fMRI are equivalent to cognitive processes engaged in the same experimental paradigms in typical behavioral lab settings. Yet very few studies examined this common assumption, and the results have been equivocal. In the current study we directly tested the effects of fMRI environment on sustained attention and response inhibition, using a Go/No-go task, among participants with (n = 42) and without (n = 21) attention deficit/hyperactivity disorder (ADHD). Participants with ADHD are characterized by deficits in these cognitive functions and may be particularly susceptible to environmental effects on attention. We found a substantial slowing of reaction time in the scanner for all participants, and a trend for enhanced sustained attention, particularly in ADHD participants with poor performance. We also report limited stability of individual differences in scores obtained in the lab and in the scanner. These findings call for cautious interpretation of neuroimaging task-related results, especially those obtained in clinical populations.