Department of General Psychology, University of Padova, Padova, Italy.
PLoS One. 2023 Oct 5;18(10):e0291275. doi: 10.1371/journal.pone.0291275. eCollection 2023.
Visual object recognition was traditionally believed to rely on a hierarchical feedforward process. However, recent evidence challenges this notion by demonstrating the crucial role of foveal retinotopic cortex and feedback signals from higher-level visual areas in processing peripheral visual information. The nature of the information conveyed through foveal feedback remains a topic of debate. To address this, we conducted a study employing a foveal mask paradigm with varying stimulus-mask onset asynchronies in a peripheral same/different task, where peripheral objects exhibited different degrees of similarity. Our hypothesis posited that simultaneous arrival of feedback and mask information in the foveal cortex would lead to neural contamination, biasing perception. Notably, when the two peripheral objects were identical, we observed a significant increase in the number of "different" responses, peaking at approximately 100 ms. Similar effect was found when the objects were dissimilar, but with an overall later timing (around 150 ms). No significant difference was found when comparing easy (dissimilar objects) and difficult trials (similar objects). The findings challenge the hypothesis that foveation planning alone accounts for the observed effects. Instead, these and previous observations support the notion that the foveal cortex serves as a visual sketchpad for maintaining and manipulating task-relevant information.
传统上认为，视觉对象识别依赖于分层前馈过程。然而，最近的证据挑战了这一观点，表明中央凹视网膜拓扑皮层和来自更高视觉区域的反馈信号在处理外围视觉信息方面起着至关重要的作用。通过中央凹反馈传递的信息的性质仍然是一个争论的话题。为了解决这个问题，我们进行了一项研究，在一个外围相同/不同任务中使用中央凹掩蔽范式，其中外围物体表现出不同程度的相似性，并改变了刺激-掩蔽起始的异步性。我们的假设是，反馈和掩蔽信息在中央凹皮层中的同时到达会导致神经污染，从而产生感知偏差。值得注意的是，当两个外围物体相同时，我们观察到“不同”反应的数量显著增加，在大约 100 毫秒时达到峰值。当物体不同时，也发现了类似的效应，但总体上延迟了（约 150 毫秒）。当比较简单（不同的物体）和困难的试验（相似的物体）时，没有发现显著差异。这些发现挑战了仅靠中央凹注视计划就能解释观察到的效应的假设。相反，这些和以前的观察结果支持了这样的观点，即中央凹皮层充当了一个视觉速写本，用于维持和操作与任务相关的信息。
