tailieunhanh - Báo cáo khoa hoc:" Biased feedback in brain-computer interfaces"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Biased feedback in brain-computer interfaces | Barbero and Grosse-Wentrup Journal of NeuroEngineering and Rehabilitation 2010 7 34 ll Hl JOURNAL OF NEUROENGINEERING http content 7 1 34 AND REHABILITATION SHORT REPORT Open Access Biased feedback in brain-computer interfaces Álvaro Barbero1 2 Moritz Grosse-Wentrup2 Abstract Even though feedback is considered to play an important role in learning how to operate a brain-computer interface BCI to date no significant influence of feedback design on BCI-performance has been reported in literature. In this work we adapt a standard motor-imagery BCI-paradigm to study how BCI-performance is affected by biasing the belief subjects have on their level of control over the BCI system. Our findings indicate that subjects already capable of operating a BCI are impeded by inaccurate feedback while subjects normally performing on or close to chance level may actually benefit from an incorrect belief on their performance level. Our results imply that optimal feedback design in BCIs should take into account a subject s current skill level. Findings Brain-computer interfaces BCIs enable subjects to communicate without using the peripheral nervous system by recording brain signals and translating these into control commands 1 . To operate a BCI subjects need to learn how to intentionally modulate certain characteristics of their brain signals in order to express their intention. For example in motor imagery one of the most frequently used experimental paradigms in BCIs 2 subjects are instructed to haptically imagine movements of either the left or right hand which typically induces a decrease in power of the electromagnetic field of the brain over contralateral sensorimotor cortex in the - and b-frequency ranges roughly 10-14 Hz and 20-30 Hz respectively 3 . The observed lateralization of this sensorimotor-rhythm SMR can then be used to infer a subject s intention. As in any form of skill acquisition subjects require feedback on their performance in order to .