Effects of mental workload during operation of a visual P300 brain-computer interface I Käthner1, S Halder1, S C Wriessnegger2, G R Müller-Putz2, A Kübler1 |
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1Institute of Psychology, University of Würzburg, Germany |
| The study aimed at identifying electrophysiological markers of fatigue and mental workload (high vs. low) and their effects on visual P300 brain-computer interface (BCI) performance. Twenty participants performed two concurrent tasks. During the BCI task, they had to focus attention on predefined characters of a 6x6-matrix, while rows and columns of the matrix flashed randomly. Mental workload was manipulated by dichotic listening tasks. Participants spelled with an average accuracy of 80% correctly selected letters in the low and 65% in the high workload conditions. A smaller P300 amplitude at Pz was observed in the high as compared to the low workload condition. Performance with the BCI was lower for the last as compared to the first run of both conditions. Increased activity in the alpha band was found at frontal, central and parietal electrode sites in the last run along with a higher subjective level of fatigue. Further, the P300 was smaller as compared to the first run. The high average performance under additional workload is promising for the use of BCIs in a home environment, where distraction is unavoidable. The identified electrophysiological markers could be used for automatic detection of fatigue or workload. [Supported by the European ICT-Program FP7-288566] |
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