Rohde Marieke, Greiner Leonie, Ernst Marc O
Department of Cognitive Neuroscience, University of Bielefeld, Universitätsstr. 25, W3-240, 33615 Bielefeld Germany; Cognitive Interaction Technology (CITEC) Centre of Excellence, University of Bielefeld, Universitätsstr. 25, W3-240, 33615 Bielefeld Germany.
Department of Cognitive Neuroscience, University of Bielefeld, Universitätsstr. 25, W3-240, 33615 Bielefeld Germany.
Acta Psychol (Amst). 2014 Mar;147:127-35. doi: 10.1016/j.actpsy.2013.07.011. Epub 2013 Aug 5.
The recalibration of perceived visuomotor simultaneity to vision-lead and movement-lead temporal discrepancies is marked by an underlying causal asymmetry, if the movement (button press) is voluntary and self-initiated; a visual stimulus lagging the button press may be interpreted as causally linked sensory feedback (intentional or causal binding), a leading visual stimulus not. Here, we test whether this underlying causal asymmetry leads to directional asymmetries in the temporal recalibration of visuomotor time perception, using an interval estimation paradigm. Participants were trained to the presence of one of three temporal discrepancies between a motor action (button press) and a visual stimulus (flashed disk): 100 ms vision-lead, simultaneity, and 100 ms movement-lead. By adjusting a point on a visual scale, participants then estimated the interval between the visual stimulus and the button press over a range of discrepancies. Comparing the results across conditions, we found that temporal recalibration appears to be implemented nearly exclusively on the movement-lead side of the range of discrepancies by a uni-lateral lengthening or shortening of the window of temporal integration. Interestingly, this marked asymmetry does not lead to a significantly asymmetrical recalibration of the point of subjective simultaneity or to significant differences in discriminability. This seeming contradiction (symmetrical recalibration of subjective simultaneity and asymmetrical recalibration of interval estimation) poses a challenge to common models of temporal order perception that assume an underlying time measurement process with Gaussian noise. Using a two-criterion model of the window of temporal integration, we illustrate that a compressive bias around perceived simultaneity (temporal integration) even prior to perceptual decisions about temporal order would be very hard to detect given the sensitivity of the psychophysical procedures commonly used.
如果运动（按键）是自愿且自我发起的，那么将视觉运动同时性重新校准为视觉领先和运动领先的时间差异时，存在一种潜在的因果不对称性；按键后出现的视觉刺激可能被解释为因果相关的感觉反馈（有意或因果绑定），而领先的视觉刺激则不然。在此，我们使用区间估计范式来测试这种潜在的因果不对称性是否会导致视觉运动时间感知的时间重新校准中出现方向不对称性。参与者接受训练，使其适应运动动作（按键）和视觉刺激（闪烁圆盘）之间三种时间差异之一的存在：100毫秒视觉领先、同时性以及100毫秒运动领先。然后，参与者通过调整视觉量表上的一个点，在一系列差异范围内估计视觉刺激和按键之间的时间间隔。比较不同条件下的结果，我们发现时间重新校准似乎几乎完全通过单侧延长或缩短时间整合窗口，在差异范围的运动领先一侧实现。有趣的是，这种明显的不对称性并不会导致主观同时性点的显著不对称重新校准，也不会导致可辨别性的显著差异。这种看似矛盾的情况（主观同时性的对称重新校准和区间估计的不对称重新校准）对假设存在带有高斯噪声的潜在时间测量过程的时间顺序感知通用模型构成了挑战。使用时间整合窗口的双标准模型，我们表明，鉴于常用心理物理学程序的敏感性，即使在对时间顺序进行感知决策之前，围绕感知到的同时性（时间整合）的压缩偏差也很难被检测到。
