Verbaarschot Ceci, Karapetyan Vahagn, Greenspon Charles M, Boninger Michael L, Bensmaia Sliman J, Sorger Bettina, Gaunt Robert A
Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA, USA.
Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands.
Nat Commun. 2025 May 1;16(1):4017. doi: 10.1038/s41467-025-58616-6.
Microstimulation of the somatosensory cortex can evoke tactile percepts in people with spinal cord injury, providing a means to restore touch. While location and intensity can be reliably conveyed, two issues that prevent creating more complex naturalistic sensations are a lack of methods to effectively scan the large stimulus parameter space and difficulties with assessing percept quality. Here, we address both challenges with an experimental paradigm that enables three male individuals with tetraplegia to control their stimulation parameters in a blinded fashion to create sensations for different virtual objects. Using this method, participants can reliably create object-specific sensations and report vivid object-appropriate characteristics. Moreover, both linear classifiers and participants can match stimulus profiles with their respective objects significantly above chance without any visual cues. Confusion between two sensations increases as the associated objects share more tactile characteristics. We conclude that while visual information contributes to the experience of the artificially evoked sensations, microstimulation in the somatosensory cortex itself can evoke intuitive percepts with a variety of tactile properties. This self-guided stimulation approach may be used to effectively characterize percepts from future stimulation paradigms.
对体感皮层进行微刺激可在脊髓损伤患者中诱发触觉感知，为恢复触觉提供了一种方法。虽然刺激的位置和强度能够可靠地传达，但阻碍产生更复杂自然感觉的两个问题是缺乏有效扫描大刺激参数空间的方法以及评估感知质量的困难。在此，我们通过一种实验范式应对这两个挑战，该范式使三名四肢瘫痪男性能够以盲法控制其刺激参数，从而为不同虚拟物体创造感觉。使用这种方法，参与者能够可靠地创造出特定物体的感觉，并报告生动且与物体相符的特征。此外，线性分类器和参与者在没有任何视觉线索的情况下，都能显著高于随机水平地将刺激特征与各自的物体相匹配。随着相关物体共享更多触觉特征，两种感觉之间的混淆会增加。我们得出结论，虽然视觉信息有助于人工诱发感觉的体验，但体感皮层自身的微刺激能够诱发具有多种触觉属性的直观感知。这种自我引导的刺激方法可用于有效表征未来刺激范式产生的感知。
