Flexibly weighted integration of tactile reference frames
Flexibly weighted integration of tactile reference frames
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DOI：
10.1016/j.neuropsychologia.2014.10.001
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发表时间：
2015-04-01
期刊：
影响因子：
2.6
通讯作者：
Heed, Tobias
中科院分区：
文献类型：
--
作者：
Badde, Stephanie;Roeder, Brigitte;Heed, Tobias
为了估计触觉刺激的位置，大脑似乎整合了不同类型的空间信息，例如基于皮肤的解剖坐标和外部空间坐标。本研究的目的是测试这些坐标的使用是否是固定的，或者它们是否根据任务上下文进行加权。参与者对两种具有不同振动特性的触觉刺激进行判断，每只手一个。首先，他们总是进行时间顺序判断（TOJ）的触觉刺激相对于刺激的手，无论是交叉或uncrossed。所产生的交叉效应，即与未交叉条件相比，交叉条件下的性能受损，被用作参考帧加权的度量，并在不同条件下进行比较。第二，在双重判断条件下，参与者随后作出判断的刺激振动特性，无论是相对于空间位置或相对于时间顺序。反应在空间二级任务重音解剖（实验1）或外部（实验2）编码。TOJ交叉效应出现在所有条件下，和次要任务没有影响主要任务的表现在非交叉的姿势。然而，空间的次要任务导致改善交叉手的性能在主要任务，但只有当次要的判断强调解剖参考框架（实验1），而不是外部参考框架（实验2）。像解剖学编码的空间次要任务，时间次要任务提高了交叉手的主要任务的性能。不同次要任务的差异影响意味着分配给解剖参考系和外部参考系的积分权重不是固定的。相反，它们是根据上下文灵活调整的，大概是通过自上而下的调节。(C)2014爱思唯尔有限公司版权所有。
To estimate the location of a tactile stimulus, the brain seems to integrate different types of spatial information such as skin-based, anatomical coordinates and external, spatiotopic coordinates. The aim of the present study was to test whether the use of these coordinates is fixed, or whether they are weighted according to the task context. Participants made judgments about two tactile stimuli with different vibration characteristics, one applied to each hand. First, they always performed temporal order judgments (TOJ) of the tactile stimuli with respect to the stimulated hands that were either crossed or uncrossed. The resulting crossing effect, that is, impaired performance in crossed compared to uncrossed conditions, was used as a measure of reference frame weighting and was compared across conditions. Second, in dual judgment conditions participants subsequently made judgments about the stimulus vibration characteristics, either with respect to spatial location or with respect to temporal order. Responses in the spatial secondary task either accented anatomical (Experiment 1) or external (Experiment 2) coding. A TOJ crossing effect emerged in all conditions, and secondary tasks did not affect primary task performance in the uncrossed posture. Yet, the spatial secondary task resulted in improved crossed hands performance in the primary task, but only if the secondary judgment stressed the anatomical reference frame (Experiment 1), rather than the external reference frames (Experiment 2). Like the anatomically coded spatial secondary task, the temporal secondary task improved crossed hand performance of the primary task. The differential influence of the varying secondary tasks implies that integration weights assigned to the anatomical and external reference frames are not fixed. Rather, they are flexibly adjusted to the context, presumably through top-down modulation. (C) 2014 Elsevier Ltd. All rights reserved.