Modulating Frustration and Agency Using Fabricated Input for Motor Imagery BCIs in Stroke Rehabilitation

Brain-computer interfaces (BCIs) can serve as a means for stroke rehabilitation, but low BCI performance can decrease agency (users’ perceived control), frustrate users and thereby hamper rehabilitation. In such rehabilitative tasks BCIs can implement fabricated input (preprogrammed positive feedback) that improve agency and frustration. Two substudies with healthy subjects and stroke patients investigated this potential through completion of a game and a simple task with: 1) 16 healthy subjects using motor imagery-based online BCI and 2) 13 stroke patients using a surrogate BCI system based on eye-blink detection through an eye-tracker to have a highly reliable input signal. Substudy 1 measured perceived control and frustration in four conditions: 1) unaltered BCI control, 2) 30% guaranteed positive feedback from fabricated input 3) 50% guaranteed negative feedback, and 4) 50% guaranteed negative feedback and 30% guaranteed positive feedback. In substudy 2, stroke patients had 50% control over outcomes and four conditions added from 0% to 50% positive feedback. In both substudies, positive feedback improved participants’ perceived control and reduced frustration with increasing improvements when the amount of positive fabricated input increased. The stroke patients did not react as much to the fabricated input as the healthy participants. Fabricated input can be concealed in both online and surrogate BCIs which can be used to improve perceived control and frustration in a game-based interaction and simple task. This suggests that BCI designers can exercise artistic freedom to create engaging motor imagery-based interactions of narrative-based games or simpler gamified interactions to facilitate improved training efforts.