Xu Yaoda
Department of Psychology, Yale University, New Haven, Connecticut 06510
eNeuro. 2025 Jul 9;12(7). doi: 10.1523/ENEURO.0162-25.2025. Print 2025 Jul.
Recent fMRI studies reported transformed representations between perception and visual working memory (VWM) in the human early visual cortex (EVC). This is inconsistent with the still widely cited original proposal of the sensory account of VWM, which argues for a shared perception-VWM representation based on successful cross-decoding of the two representations. Although cross-decoding was usually lower than within-VWM decoding and consistent with transformed VWM representations, this has been attributed to experimental differences between perceptual and VWM tasks: once they are equated, the same representation is expected to exist in both. Including human participants of both sexes, this study compared target and distractor representations during the same VWM delay period for the same objects, thereby equating experimental differences. Even with strong VWM representations present throughout the occipitotemporal cortex (OTC, including EVC) and posterior parietal cortex (PPC), fMRI cross-decoding revealed significant representational differences between distractors (perception) and targets (VWM) in both regions. Similar differences existed between target encoding (perception) and delay (VWM), being greater in OTC than PPC, indicating more invariant target representations in PPC than OTC. As only part of the sensory input is usually task-relevant, sustaining sensory input in VWM without selection/refinement/consolidation is both taxing and unnecessary. Transformed representations, mediated by task goals and associative areas coding task-relevant information (e.g., PPC), can easily account for these and other recent findings. A task-driven transformed account of VWM thus better captures the nature of VWM representation in the human brain (including EVC) than the sensory representations originally proposed by the sensory account of VWM.
近期的功能磁共振成像（fMRI）研究报告称，在人类早期视觉皮层（EVC）中，感知与视觉工作记忆（VWM）之间存在表征转换。这与VWM的感觉理论中仍被广泛引用的最初观点不一致，该理论主张基于两种表征的成功交叉解码而存在共享的感知-VWM表征。尽管交叉解码通常低于VWM内解码，且与转换后的VWM表征一致，但这被归因于感知任务和VWM任务之间的实验差异：一旦两者等同，预计在两者中会存在相同的表征。本研究纳入了男女参与者，在相同的VWM延迟期内，针对相同物体比较了目标和干扰物的表征，从而消除了实验差异。即使在整个枕颞叶皮层（OTC，包括EVC）和顶叶后皮层（PPC）中都存在强烈的VWM表征，fMRI交叉解码仍显示出这两个区域中干扰物（感知）和目标（VWM）之间存在显著的表征差异。目标编码（感知）和延迟（VWM）之间也存在类似差异，在OTC中比在PPC中更大，这表明PPC中的目标表征比OTC中的更具不变性。由于通常只有部分感觉输入与任务相关，在VWM中维持感觉输入而不进行选择/细化/巩固既费力又不必要。由任务目标和编码任务相关信息的联合区域（例如PPC）介导的转换表征可以轻松解释这些及其他近期发现。因此，与VWM的感觉理论最初提出的感觉表征相比，任务驱动的VWM转换理论能更好地捕捉人类大脑（包括EVC）中VWM表征的本质。
