ABSTRACT

Object substitution masking (OSM) involves reduced perceptibility by a briefly lingering mask despite no spatial target-mask overlap. Two primary accounts for this phenomenon posit differences in object representation in visual short-term memory (VSTM). In the object substitution account a single representation resides in VSTM: a lone mask when attention is not focused on the target, and a lone target+mask when attention is focused on the target. The object updating account assumes individualization, with mask-alone and target+mask representations concurrently present in VSTM in correct delayed-offset OSM trials. We explored object individuation in OSM, focusing on the quantity of representations in VSTM in two OSM tasks with low (Easy Search) and high (Difficult Search) attentional demands, using event-related potentials (ERPs). Individuation was indicated in correct trials, with ERPs showing greater negativity in the sustained posterior contralateral negativity (SPCN) component for delayed compared to co-terminating offset conditions, consistent with greater VSTM load in delayed-offset. This effect, indicating target+mask and mask-alone as distinct memory representations, was found in Easy Search only. Additionally, no SPCN difference was found between correct and incorrect delayed trials in Difficult Search. We discuss our results in the context of individuation and perceptual load in OSM.

摘要

尽管没有空间目标蒙版重叠，但对象替换蒙版（OSM）会通过短暂停留的蒙版而降低可感知性。造成这种现象的两个主要原因是视觉短期记忆（VSTM）中对象表示形式的差异。在对象替换帐户中，单一表示形式驻留在VSTM中：当注意力未集中在目标上时是一个单独的掩码，而在注意力未集中在目标上时是一个单独的target +掩码。对象更新帐户假设是个性化的，在正确的延迟偏移OSM试验中，VSTM同时存在单独的掩码和目标+掩码表示。我们探索了OSM中的对象个体化，重点是使用事件相关电位（ERP）来关注注意力需求低（容易搜索）和高（困难搜索）的两个OSM任务中VSTM中的表示数量。在正确的试验中表明了个体化，ERP对延迟性持续对侧偏斜负性（SPCN）分量显示出更大的负向性，而与共终止偏移条件相比，与延迟性偏移中更大的VSTM负荷相符。仅在轻松搜索中发现了这种效果，表明目标+掩码和单独的掩码是不同的内存表示形式。此外，在“困难搜索”中，正确和不正确的延迟试验之间未发现SPCN差异。我们在OSM的个性化和感知负载的情况下讨论我们的结果。仅在Easy Search中找到指示target + mask和单独的mask作为不同的内存表示形式。此外，在“困难搜索”中，正确和不正确的延迟试验之间未发现SPCN差异。我们在OSM的个性化和感知负载的情况下讨论我们的结果。仅在Easy Search中找到指示target + mask和单独的mask作为不同的内存表示形式。此外，在“困难搜索”中，正确和不正确的延迟试验之间未发现SPCN差异。我们在OSM的个性化和感知负载的情况下讨论我们的结果。