Table 5.

Main differences between synchronous and asynchronous BCIs.

Approach	Advantages	Disadvantages
Synchronous BCI	– Simpler design and performance evaluation – The user can avoid generating artifacts since they can perform blinks and other eye movements when brain signals are not analyzed	– Does not offer a more natural mode of interaction
Asynchronous BCI	– No requirement to wait for external cues – Offers a more natural mode of interaction	– Much more complicate design – More difficult evaluation