  In this paper we introduce the concept of Brain-Computer Interface (BCI)
inhibitor, which is meant to standby the BCI until the user is ready, in order
to improve the overall performance and usability of the system. BCI inhibitor
can be defined as a system that monitors user's state and inhibits BCI
interaction until specific requirements (e.g. brain activity pattern, user
attention level) are met. In this pilot study, a hybrid BCI is designed and
composed of a classic synchronous BCI system based on motor imagery and a BCI
inhibitor. The BCI inhibitor initiates the control period of the BCI when
requirements in terms of brain activity are reached (i.e. stability in the beta
band). Preliminary results with four participants suggest that BCI inhibitor
system can improve BCI performance.
