Arima Yasuaki, Nakamura Kae, Mori Kimihiko, Hashimoto Shingo, Wakida Masanori, Ishii Hironori, Hase Kimitaka
Department of Rehabilitation Medicine, Kansai Medical University Hospital, Hirakata, Osaka 573-1191, Japan.
Department of Physiology, Kansai Medical University, Hirakata, Osaka 573-1010, Japan.
eNeuro. 2025 Jan 17;12(1). doi: 10.1523/ENEURO.0279-24.2024. Print 2025 Jan.
The subjective visual vertical (VV), the visually estimated direction of gravity, is essential for assessing vestibular function and visuospatial cognition. In this study, we aimed to investigate the mechanisms underlying altered VV perception in stroke participants with unilateral spatial neglect (USN), specifically by examining their eye movement patterns during VV judgment tasks. Participants with USN demonstrated limited eye movement scanning along a rotating bar, often fixating on prominent ends, such as the top or bottom. This suggests a reflexive response to visually salient areas, potentially interfering with accurate VV perception. In contrast, participants without USN showed broader scanning around the center of the bar. Notably, participants with USN without frontal lobe lesions occasionally exhibited extended scanning that included the bar's center, which was associated with accurate VV judgments. These findings suggest that (1) a tendency to fixate on peripheral, prominent areas and (2) frontal lobe involvement in disengaging and redirecting spatial attention may influence VV perception in USN. Based on these results, targeted rehabilitation strategies that encourage individuals with USN to extend their visual scanning beyond prominent endpoints and include central areas could improve VV accuracy. This study highlights the specific eye movement behaviors contributing to VV misperception, emphasizing the importance of training that broadens scanning to improve VV perception effectively.
主观垂直视觉（VV），即视觉上对重力方向的估计，对于评估前庭功能和视觉空间认知至关重要。在本研究中，我们旨在探究单侧空间忽视（USN）的中风参与者中VV感知改变的潜在机制，具体方法是检查他们在VV判断任务期间的眼动模式。患有USN的参与者在沿着旋转杆进行眼动扫描时表现出受限情况，经常固定在突出的端点上，例如顶部或底部。这表明对视觉上显著区域的一种反射性反应，可能会干扰准确的VV感知。相比之下，没有USN的参与者在杆的中心周围进行了更广泛的扫描。值得注意的是，没有额叶病变的USN参与者偶尔会表现出包括杆中心在内的扩展扫描，这与准确的VV判断相关。这些发现表明：（1）倾向于固定在周边突出区域，以及（2）额叶参与解除和重新引导空间注意力，可能会影响USN中的VV感知。基于这些结果，鼓励患有USN的个体将其视觉扫描扩展到突出端点之外并包括中心区域的针对性康复策略，可以提高VV的准确性。这项研究突出了导致VV感知错误的特定眼动行为，强调了拓宽扫描以有效改善VV感知的训练的重要性。
