The FDA’s device center has a mantra of sorts when it comes to the details, or lack thereof, in guidance, which is “talk to us early and often.” For device makers eyeing the brain-computer interface (BCI) device space, this mantra has been applied to the question of pivotal study enrollment numbers, suggesting that some sponsors will find their pivotal studies come with a case of sticker shock sufficient to force them to rethink their research and developmental plans.