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

Abstract

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 eyeblink 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.

Implementing Performance Accommodation Mechanisms in Online BCI for Stroke Rehabilitation: A Study on Perceived Control and Frustration

“…The BCI in this study was based on kinesthetic MI of a palmar grasp of the right hand and implemented using the “Motor Imagery BCI” scenario in OpenViBE [ 47 ]. A similar setup was used previously (see, e.g., [ 15 , 35 , 48 ]). Continuous EEG was recorded using a cap with sintered Ag/AgCl electrodes (OpenBCI, USA) and amplified using a Cyton Biosensing Board (OpenBCI, USA).…”

“…In accordance with previous BCI-related studies, we focused on the user experience [ 34 , 35 , 36 , 37 ], and the dependent variables we measured were frustration and perceived control. After each condition, participants rated on a Likert scale their perceived control (“ I felt I was in control of the fisherman reeling in the fish.…”

“…The BCI performance may be enhanced in various ways by selecting the optimal pre-processing techniques [ 24 , 25 , 26 ], features [ 25 , 27 , 28 , 29 , 30 ], classifiers [ 29 , 31 ], or by focusing on user instructions and training [ 23 , 32 , 33 ]. By improving the BCI performance, the patients’ perceived control and frustration improve as well [ 34 , 35 , 36 , 37 , 38 , 39 , 40 ], which may help them maintain interest in the training. Moreover, frustration has a detrimental effect on BCI performance with increasing frustration leading to worse BCI performance [ 39 ].…”

“…Despite the use of optimal signal processing techniques or learning principles, the BCI performance may still be poor for some users, or other factors may impede the BCI performance, such as incompetence or fear [ 41 ]. A way to tackle this is by injecting concealed, artificial, positive feedback and in this way improve the perceived BCI performance [ 34 , 35 ]. This approach can only be implemented in a meaningful way in synchronous BCIs with binary input (MI vs. idle activity) [ 35 ].…”

“…A way to tackle this is by injecting concealed, artificial, positive feedback and in this way improve the perceived BCI performance [ 34 , 35 ]. This approach can only be implemented in a meaningful way in synchronous BCIs with binary input (MI vs. idle activity) [ 35 ]. Alternatively, game mechanics can be used to assist users, such that they maintain interest in the training, and the mechanics conceal the actual BCI performance.…”