Visual and vestibular impacts on tactile remapping: an exploration of reference frames and response demands.

感知被触摸物体的位置似乎是一项自动伴随触觉而来的简单任务；然而，需要整合多种信息源。手指末端的感觉必须与手臂的姿势、身体的位置和眼睛的信息融为一体。将触觉从皮肤表面转换为身体外部空间中的位置称为触觉重新映射。在本项目中，我们使用触觉时间顺序判断(TOJ)任务来探索重映射过程。当双手放在身体中线上时，可以观察到严重的缺陷--缺陷大小的变化提供了有关大脑如何将触觉刺激的内部表征重新映射到外部表征的信息。 本研究的目的是研究前庭信号对这一重新映射过程的贡献。前庭器官向大脑发送关于头部相对于重力的方向的信号。以前关于重新映射的研究或暗示或明确地假设，视觉主导。我们实验室最近的工作证明了前庭输入的深远贡献。我们通过四个融合的项目来探索这些贡献。首先，我们改变了对参与者的反应要求，使他们偏向基于身体或基于空间的表征--这种操纵会影响赤字的大小。其次，我们使用约克大学的翻滚房间将参与者放置在相对于重力的不同角度，并独立操纵视觉世界的相对角度。这允许确定来自两个感官来源的相对贡献。第三，我们电刺激前庭系统引入噪音，这掩盖了它对我们直立感的贡献-这将提供一个衡量该系统如何对重新映射过程做出贡献的指标。最后，我们利用脑电(EEG)挖掘重新映射背后的神经过程。这四个项目集中在理解我们对外部空间的表征是如何构建的，以及触觉刺激是如何重新映射到那个表征中的。 对于专注于基础研究的科学家来说，这些数据将有助于整合来自多个研究领域的结果，这两个领域都与多感觉整合有关，以及特定于通道的领域。在应用上，这些发现将支持开发更高保真度的人机界面，这反过来将支持增强感知工具的开发。增强知觉可以帮助丧失知觉的人恢复功能，或者为没有失去知觉的人提供额外的信息。最后，这些发现将支持对人类如何在外层空间发挥作用的研究。所有这些影响将支持加拿大的研究，并在应用中支持加拿大公民的研究。

Perceiving the location of a touched object seems like a simple task that comes automatically with the tactile sensation; yet, integration of multiple sources of information is required. The sensation at the end of your finger must be integrated with the posture of your arm, the position of your body, and the information from your eyes. Transforming the tactile sense from the skin’s surface to provide a location in space external to the body is termed tactile remapping. In the present project we use the tactile temporal order judgment (TOJ) task to explore the remapping processes. When the hands are placed across the body midline a profound deficit is observed—changes in the size of deficit are informative about how the brain remaps internal representations of tactile stimuli to an external representation. The goal of the present proposal is to examine the contribution of vestibular signals to this remapping process. The vestibular organs send signals to the brain about orientation of the head relative to gravity. Previous research on remapping had assumed, either implicitly or explicitly, that vision dominated. Recent work from our lab demonstrates a profound contribution from vestibular inputs. We explore these contributions through four converging projects. First, we change the response demands on participants to bias them to a body-based or space-based representation—this manipulation affects the size of the deficit. Second, we use the Tumbling Room at York University to place participants at various angles relative to gravity and independently manipulate the relative angle of the visual world. This allows a determination of the relative contributions from the two sensory sources. Third, we electrically stimulate the vestibular system to introduce noise, which masks its contribution to our sense of upright—this will provide a measure of how this system contributes to the remapping process. Finally, we tap the neural processes underlying remapping use Electroencephalography (EEG). The four projects converge on the understanding of how our representation of external space is constructed, and how tactile stimuli are remapped into that representation. For scientists focused on basic research, these data will help integrate findings from multiple research domains, both related to multisensory integration, and for modality-specific domains. In application, these findings will support development of higher fidelity human-computer interfaces, which will, in turn, support the development of augmented perception tools. Augmented perception can help restore function for people who have lost a sense, or provide additional information for those who have not. Finally, these findings will support research into how humans can function in outer space. All of these impacts will support research in Canada, and, in application, its citizens.