Keetch Katherine M, Glazebrook Cheryl M, Lyons James, Lam Melanie Y, Weeks Daniel J, Elliott Digby
McMaster University, Hamilton, Ont., L8S 4K1 Canada.
Neurosci Lett. 2006 Oct 2;406(1-2):117-21. doi: 10.1016/j.neulet.2006.07.025. Epub 2006 Aug 9.
When task requirements were known in advance, Glazebrook et al. [C.M. Glazebrook, V.P. Dhillon, K.M. Keetch, J. Lyons, E. Amazeen, D.J. Weeks, D. Elliott, Perception-action and the Müller-Lyer illusion: amplitude or endpoint bias?, Exp. Brain Res. 160 (2005) 71-78.] demonstrated that perceptual biases associated with the Müller-Lyer illusion resulted from a misperception of figure extent, while manual aiming biases resulted from a misperception of vertex position. In this study, we examined the degree to which prior knowledge of task requirements influenced how participants coded visual-spatial information associated with Müller-Lyer configurations. Specifically, we investigated how illusory biases are affected when uncertainty exists as to whether participants will be required to make a perceptual-cognitive decision about the length of a figure or complete a rapid aiming movement to a figure vertex. Although aiming movements were completed in a similar manner regardless of the prior knowledge condition, perceptual biases were associated with a misperception of extent when the task was known and a misperception of both extent and position when the task was unknown. These findings indicate that people are flexible in the manner in which they code visual-spatial information.
当任务要求提前已知时，格雷泽布鲁克等人[C.M. 格雷泽布鲁克、V.P. 迪隆、K.M. 基奇、J. 莱昂斯、E. 阿马津、D.J. 威克斯、D. 埃利奥特，知觉 - 动作与缪勒 - 莱尔错觉：幅度偏差还是端点偏差？，《实验脑研究》160 (2005) 71 - 78]证明，与缪勒 - 莱尔错觉相关的知觉偏差源于对图形范围的错误感知，而手动瞄准偏差则源于对顶点位置的错误感知。在本研究中，我们考察了任务要求的先验知识在多大程度上影响参与者对与缪勒 - 莱尔图形相关的视觉空间信息的编码方式。具体而言，我们研究了当参与者不确定是需要对图形长度做出知觉 - 认知决策还是对图形顶点完成快速瞄准动作时，错觉偏差会受到怎样的影响。尽管无论先验知识条件如何，瞄准动作都以相似的方式完成，但当任务已知时，知觉偏差与对范围的错误感知相关，而当任务未知时，知觉偏差与对范围和位置的错误感知都相关。这些发现表明，人们在编码视觉空间信息的方式上具有灵活性。
