Institute of Psychology, University of Würzburg, Würzburg, Germany.
Sci Rep. 2022 Aug 17;12(1):14006. doi: 10.1038/s41598-022-18088-w.
Brain-computer interfaces (BCI) often rely on visual stimulation and feedback. Potential end-users with impaired vision, however, cannot use these BCIs efficiently and require a non-visual alternative. Both auditory and tactile paradigms have been developed but are often not sufficiently fast or accurate. Thus, it is particularly relevant to investigate if and how users can train and improve performance. We report data from 29 healthy participants who trained with a 4-choice tactile P300-BCI during five sessions. To identify potential training factors, we pre-post assessed the robustness of the BCI performance against increased workload in a dual task condition and determined the participants' somatosensory sensitivity thresholds with a forced-choice intensity discrimination task. Accuracy (M = 79.2% to 92.0%) and tactually evoked P300 amplitudes increased significantly, confirming successful training. Pre-post somatosensory sensitivity increased, and workload decreased significantly, but results of the dual task condition remained inconclusive. The present study confirmed the previously reported feasibility and trainability of our tactile BCI paradigm within a multi-session design. Importantly, we provide first evidence of improvement in the somatosensory system as a potential mediator for the observed training effects.
脑机接口（BCI）通常依赖于视觉刺激和反馈。然而，视力受损的潜在终端用户无法有效地使用这些 BCI，需要一种非视觉替代方案。已经开发了听觉和触觉范式，但它们通常不够快或不够准确。因此，研究用户是否可以以及如何进行训练和提高性能是非常重要的。我们报告了 29 名健康参与者的数据，他们在五个会话中使用 4 选择触觉 P300-BCI 进行了训练。为了确定潜在的训练因素，我们在双重任务条件下预先评估了 BCI 性能对增加工作量的稳健性，并使用强制选择强度辨别任务确定了参与者的体感敏感性阈值。准确性（M=79.2%至 92.0%）和触觉 P300 幅度显着增加，证实了成功的训练。预先评估的体感敏感性增加，工作量显着减少，但双重任务条件的结果仍不确定。本研究在多会话设计中证实了我们的触觉 BCI 范式以前报道的可行性和可训练性。重要的是，我们提供了第一个证据，证明体感系统的改善是观察到的训练效果的潜在介导因素。
