Meeting the expectations from brain-computer interfaces

Brain-computer interfaces (BCIs) are often evaluated in terms of performance and seldom for usability. However in some application domains, such as entertainment computing, user experience evaluation is vital. User experience evaluation in BCI systems, especially in entertainment applications such as games, can be biased due to the novelty of the interface. However, as the novelty will eventually vanish, what matters is the user experience related to the unique features offered by BCI. Therefore it is a viable approach to compare BCI to other novel modalities, such as a speech or motion recognizer, rather than the traditional mouse and keyboard. In the study that we present in this article, our participants played a computer game with a BCI and an automatic speech recognizer (ASR), and they rated their expectations and experiences for both modalities. Our analysis on subjective ratings revealed that both ASR and BCI were successful in satisfying participants' expectations in general. Participants found speech control easier to learn than BCI control. They indicated that BCI control induced more fatigue than they expected.