Boström Kim Joris, Warzecha Anne-Kathrin
Psych. Inst. II, Universität Münster, 48149 Münster, Germany.
Vision Res. 2010 Apr 21;50(9):870-82. doi: 10.1016/j.visres.2010.02.010. Epub 2010 Feb 20.
So far, it remains largely unresolved to what extent neuronal noise affects behavioral responses. Here, we investigate, where in the human visual motion pathway noise originates that limits the performance of the entire system. In particular, we ask whether perception and eye movements are limited by a common noise source, or whether processing stages after the separation into different streams limit their performance. We use the ocular following response of human subjects and a simultaneously performed psychophysical paradigm to directly compare perceptual and oculomotor system with respect to their speed discrimination ability. Our results show that on the open-loop condition the perceptual system is superior to the oculomotor system and that the responses of both systems are not correlated. Two alternative conclusions can be drawn from these findings. Either the perceptual and oculomotor pathway are effectively separate, or the amount of post-sensory (motor) noise is not negligible in comparison to the amount of sensory noise. In view of well-established experimental findings and due to plausibility considerations, we favor the latter conclusion.
到目前为止，神经元噪声在多大程度上影响行为反应在很大程度上仍未得到解决。在这里，我们研究在人类视觉运动通路中，限制整个系统性能的噪声起源于何处。具体而言，我们要问感知和眼动是否受共同噪声源的限制，或者在分离成不同信息流后的处理阶段是否会限制它们的性能。我们利用人类受试者的眼球跟随反应和同时进行的心理物理学范式，直接比较感知系统和动眼系统在速度辨别能力方面的表现。我们的结果表明，在开环条件下，感知系统优于动眼系统，且两个系统的反应不相关。从这些发现中可以得出两个备选结论。要么感知通路和动眼通路是有效分离的，要么与感觉噪声量相比，感觉后（运动）噪声量不可忽略。鉴于已确立的实验结果并出于合理性考虑，我们倾向于后一个结论。
