Scholes Chris, McGraw Paul V, Roach Neil W
Visual Neuroscience Group, School of Psychology, University of Nottingham, Nottingham NG7 2RD, United Kingdom
Visual Neuroscience Group, School of Psychology, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
Proc Natl Acad Sci U S A. 2021 Feb 9;118(6). doi: 10.1073/pnas.2012937118.
Perceptual stability is facilitated by a decrease in visual sensitivity during rapid eye movements, called saccadic suppression. While a large body of evidence demonstrates that saccadic programming is plastic, little is known about whether the perceptual consequences of saccades can be modified. Here, we demonstrate that saccadic suppression is attenuated during learning on a standard visual detection-in-noise task, to the point that it is effectively silenced. Across a period of 7 days, 44 participants were trained to detect brief, low-contrast stimuli embedded within dynamic noise, while eye position was tracked. Although instructed to fixate, participants regularly made small fixational saccades. Data were accumulated over a large number of trials, allowing us to assess changes in performance as a function of the temporal proximity of stimuli and saccades. This analysis revealed that improvements in sensitivity over the training period were accompanied by a systematic change in the impact of saccades on performance-robust saccadic suppression on day 1 declined gradually over subsequent days until its magnitude became indistinguishable from zero. This silencing of suppression was not explained by learning-related changes in saccade characteristics and generalized to an untrained retinal location and stimulus orientation. Suppression was restored when learned stimulus timing was perturbed, consistent with the operation of a mechanism that temporarily reduces or eliminates saccadic suppression, but only when it is behaviorally advantageous to do so. Our results indicate that learning can circumvent saccadic suppression to improve performance, without compromising its functional benefits in other viewing contexts.
在快速眼动期间视觉敏感度降低有助于感知稳定性,这被称为扫视抑制。虽然大量证据表明扫视编程具有可塑性,但对于扫视的感知后果是否可以改变却知之甚少。在此,我们证明在一项标准的视觉噪声检测任务学习过程中,扫视抑制会减弱,甚至有效消失。在7天的时间里,44名参与者接受训练,在跟踪眼睛位置的同时检测动态噪声中嵌入的短暂、低对比度刺激。尽管被要求注视,但参与者仍会定期进行小幅度的注视性扫视。数据在大量试验中积累,使我们能够评估作为刺激和扫视时间接近度函数的性能变化。该分析表明,在训练期间敏感度的提高伴随着扫视对性能影响的系统性变化——第1天强大的扫视抑制在随后几天逐渐下降,直到其幅度变得与零难以区分。这种抑制的消失不能用扫视特征中与学习相关的变化来解释,并且可以推广到未训练的视网膜位置和刺激方向。当学习到的刺激时间受到干扰时,抑制恢复,这与一种机制的运作一致,该机制会暂时减少或消除扫视抑制,但只有在这样做在行为上有利时才会如此。我们的结果表明,学习可以规避扫视抑制以提高性能,同时不损害其在其他观看情境中的功能益处。