Volcic Robert, Kappers Astrid M L
Helmholtz Institute, Utrecht University, Princetonplein 5, 3584 CC, Utrecht, The Netherlands.
Exp Brain Res. 2008 Jun;188(2):199-213. doi: 10.1007/s00221-008-1353-5. Epub 2008 Mar 27.
The main goal of our study is to gain insight into the reference frames involved in three-dimensional haptic spatial processing. Previous research has shown that two-dimensional haptic spatial processing is prone to large systematic deviations. A weighted average model that identifies the origin of the systematic error patterns in the biasing influence of an egocentric reference frame on the allocentric reference frame was proposed as an explanation of the results. The basis of the egocentric reference frame was linked either to the hand or to the body. In the present study participants had to construct a field of parallel bars that could be oriented in three dimensions. First, systematic error patterns were found also in this three-dimensional haptic parallelity task. Second, among the different models tested for their accuracy in explaining the error patterns, the Hand-centered weighted average model proved to most closely resemble the data. A participant-specific weighting factor determined the biasing influence of the hand-centered egocentric reference frame. A shift from the allocentric towards the egocentric frame of reference of approximately 20% was observed. These results support the hypothesis that haptic spatial processing is a product of the interplay of diverse, but synergistically operating frames of reference.
我们研究的主要目标是深入了解三维触觉空间处理中涉及的参考框架。先前的研究表明，二维触觉空间处理容易出现较大的系统偏差。有人提出了一个加权平均模型，该模型确定了以自我为中心的参考框架对不以自我为中心的参考框架的偏差影响中系统误差模式的起源，以此来解释研究结果。以自我为中心的参考框架的基础要么与手相关，要么与身体相关。在本研究中，参与者必须构建一个可以在三维空间中定向的平行杆场。首先，在这个三维触觉平行度任务中也发现了系统误差模式。其次，在为解释误差模式的准确性而测试的不同模型中，以手为中心的加权平均模型被证明与数据最为接近。一个特定于参与者的加权因子决定了以手为中心的自我中心参考框架的偏差影响。观察到参考框架从不以自我为中心向以自我为中心的转变约为20%。这些结果支持了这样一种假设，即触觉空间处理是多种但协同运作的参考框架相互作用的产物。
