ABSTRACT

In visual crowding, an item representation is degraded by adjacent flanker items. Recently, the related phenomenon of visual working memory (VWM) crowding has been used to evaluate shared mechanisms between memory and perception. However, some previous studies that investigated VWM crowding suggested that it stemmed from encoding, rather than memory maintenance. In the current study, we evaluated two measures in simultaneously-presented arrays: anisotropy for radially vs. tangentially configured arrays, and effect of target to array proximity (array middle vs. edge targets). Simultaneously presented arrays evoked effects in both measures. We then compared the data from the current study to that from our previous study that used sequential presentation, and thus avoided encoding-based explanations for crowding. We predicted that we would observe greater crowding for simultaneous than sequential presentation because simultaneous arrays allow for two opportunities for crowding—encoding and maintenance—while sequential arrays only allow for maintenance-based crowding. Surprisingly, we observed that both measures were similar across simultaneous and sequential arrays. These results indicate that VWM crowding does not have an additive error mechanism across encoding and maintenance. Moreover, the anisotropy result suggests that both simultaneous and sequential array VWM crowding is influenced by retinotopy in the early visual cortex.

摘要

在视觉拥挤中，项目表示会被相邻的侧翼项目降级。最近，视觉工作记忆（VWM）拥挤的相关现象已被用于评估记忆和感知之间的共享机制。然而，之前一些调查 VWM 拥挤的研究表明它源于编码，而不是记忆维护。在当前的研究中，我们评估了同时呈现的阵列中的两个测量值：径向与切向配置阵列的各向异性，以及目标与阵列邻近度的影响（阵列中间与边缘目标）。同时呈现的阵列在两种测量中都引起了影响。然后，我们将当前研究的数据与我们之前使用顺序呈现的研究的数据进行了比较，从而避免了基于编码的拥挤解释。我们预测，我们将观察到同步呈现比顺序呈现更大的拥挤，因为同步阵列允许两种拥挤的机会——编码和维护——而顺序阵列只允许基于维护的拥挤。令人惊讶的是，我们观察到这两种测量在同时和顺序阵列中是相似的。这些结果表明，VWM 拥挤在编码和维护之间没有附加错误机制。此外，各向异性结果表明，同时和顺序阵列 VWM 拥挤都受到早期视觉皮层视网膜拓扑的影响。令人惊讶的是，我们观察到这两种测量在同时和顺序阵列中是相似的。这些结果表明，VWM 拥挤在编码和维护之间没有附加错误机制。此外，各向异性结果表明，同时和顺序阵列 VWM 拥挤都受到早期视觉皮层视网膜拓扑的影响。令人惊讶的是，我们观察到这两种测量在同时和顺序阵列中是相似的。这些结果表明，VWM 拥挤在编码和维护之间没有附加错误机制。此外，各向异性结果表明，同时和顺序阵列 VWM 拥挤都受到早期视觉皮层视网膜拓扑的影响。