Salahub Christine M, Emrich Stephen M
Department of Psychology, Brock University, L2S 3A1, St. Catharines, Ontario, Canada.
Atten Percept Psychophys. 2018 Feb;80(2):387-401. doi: 10.3758/s13414-017-1459-6.
To keep track of dynamically changing objects in one's environment, it is necessary to individuate them from other objects, both temporally and spatially. Spatially, objects can be selected from nearby distractors using selective attention. Temporally, object updating processes incorporate new information into existing representations over time. Both of these processes have been implicated in a type of visual masking called object-substitution masking (OSM). Previous studies have found that the number of distractors (impacting selective attention) interacts with the strength of OSM. However, it has been suggested that this interaction is an artifact of ceiling performance at low set sizes, rather than necessitating a failure of attention during masking. Using event-related potentials (ERPs), we examined whether set size and masking interact as measured by markers of selective attention (N2pc) and visual working memory consolidation/maintenance (SPCN). Set size was found to affect the N2pc (200-350 ms) and late SPCN (500-650 ms), reflecting increased demands on selective attention and unnecessary storage respectively. An early window of the SPCN (350-500 ms) was affected by masking, suggesting that OSM influences object consolidation processes in this window, independent of the number of distractors. Overall, it was found that selective attention and visual awareness are dissociable neural processes in OSM, and that they are independently affected by set size and masking manipulations. Moreover, we found that the early SPCN may reflect disruptions to object consolidation, potentially revealing a neural mechanism supporting an object individuation-through-updating account of OSM.
为了追踪人所处环境中动态变化的物体，有必要在时间和空间上把它们与其他物体区分开来。在空间上，可以通过选择性注意从附近的干扰物中挑选出物体。在时间上，物体更新过程会随着时间的推移将新信息纳入现有的表征中。这两个过程都与一种称为物体替代掩蔽（OSM）的视觉掩蔽类型有关。先前的研究发现，干扰物的数量（影响选择性注意）与OSM的强度相互作用。然而，有人认为这种相互作用是低集合大小时天花板效应的假象，而不是在掩蔽期间注意力必然失败。我们使用事件相关电位（ERP）来研究集合大小和掩蔽是否如通过选择性注意标记（N2pc）和视觉工作记忆巩固/维持（SPCN）所测量的那样相互作用。发现集合大小会影响N2pc（200 - 350毫秒）和晚期SPCN（500 - 650毫秒），分别反映出对选择性注意和不必要存储的需求增加。SPCN的早期窗口（350 - 500毫秒）受掩蔽影响，这表明OSM在这个窗口中影响物体巩固过程，与干扰物的数量无关。总体而言，发现在OSM中选择性注意和视觉意识是可分离的神经过程，并且它们分别受到集合大小和掩蔽操作的独立影响。此外，我们发现早期SPCN可能反映了物体巩固的中断，这可能揭示了一种支持通过更新进行物体个体化的OSM解释的神经机制。
