Pilling Michael, Guest Duncan, Andrews Mark
Oxford Brookes University, UK.
Nottingham Trent University, UK.
Perception. 2019 Feb;48(2):138-161. doi: 10.1177/0301006619825782.
Two experiments examined the effect of object substitution masking (OSM) on the perceptual errors in reporting the orientation of a target. In Experiment 1, a four-dot trailing mask was compared with a simultaneous-noise mask. In Experiment 2, the four-dot and noise masks were factorially varied. Responses were modelled using a mixture regression model and Bayesian inference to deduce whether the relative impacts of OSM on guessing and precision were the same as those of a noise mask, and thus whether the mechanism underpinning OSM is based on increasing noise rather than a substitution process. Across both experiments, OSM was associated with an increased guessing rate when the mask trailed target offset and a reduction in the precision of the target representation (although the latter was less reliable across the two experiments). Importantly, the noise mask also influenced both guessing and precision, but in a different manner, suggesting that OSM is not simply caused by increasing noise. In Experiment 2, the effects of OSM and simultaneous-noise interacted, suggesting the two manipulations involve common mechanisms. Overall results suggest that OSM is often a consequence of a substitution process, but there is evidence that the mask increases noise levels on trials where substitution does not occur.
两项实验研究了客体替代掩蔽（OSM）对报告目标方向时感知错误的影响。在实验1中，将四点拖尾掩蔽与同步噪声掩蔽进行了比较。在实验2中，对四点掩蔽和噪声掩蔽进行了析因变化。使用混合回归模型和贝叶斯推理对反应进行建模，以推断OSM对猜测和精度的相对影响是否与噪声掩蔽相同，从而推断支撑OSM的机制是否基于增加噪声而非替代过程。在两个实验中，当掩蔽跟随目标偏移时，OSM与猜测率增加相关，并且目标表征的精度降低（尽管在两个实验中后者不太可靠）。重要的是，噪声掩蔽也影响猜测和精度，但方式不同，这表明OSM并非简单地由增加噪声引起。在实验2中，OSM和同步噪声的效应相互作用，表明这两种操作涉及共同机制。总体结果表明，OSM通常是替代过程的结果，但有证据表明，在未发生替代的试验中，掩蔽会增加噪声水平。
