The Influence of Decoding Accuracy on Perceived Control: A Simulated BCI Study

Understanding the relationship between the decoding accuracy of a brain-computer in-terface (BCI) and a subject’s subjective feeling of control is important for determining a lower limit on decoding accuracy for a BCI that is to be deployed outside a laboratory en-vironment. We investigated this relationship by systematically varying the level of control in a simulated BCI task. We find that a binary decoding accuracy of 65 % is required for users to report more often than not that they are feeling in control of the system. Decoding accuracies above 75%, on the other hand, added little in terms of the level of perceived control. We further find that the probability of perceived control does not only depend on the actual decoding accuracy, but is also in influenced by whether subjects successfully complete the given task in the allotted time frame.