The additional fee must be paid to ACM. This text field is large enough to hold the appropriate release statement assuming it is single spaced in a sans-serif 7 point font. Every submission will be assigned their own unique DOI string to be included here. Abstract Brain-Computer Interfaces (BCIs) have brought new, exciting and promising perspectives of interaction. On the one hand, active BCIs enable users to control applications (such as assistive technologies or video games) using their brain activity alone. On the other hand, passive BCIs bring the possibility of adapting an application/interface based on users' mental states. In this course, we first aim at introducing BCIs to the HCI community and to discuss how BCI-based applications could benefit HCI. Then, in a practical session, we will propose all participants to implement their own BCI, in a very simple way, using the free Open-ViBE software. Finally, we will have discussions about what is possible or not with BCIs, what are their pros and cons.