From moment to moment, the visual properties of objects in the world fluctuate because of external factors like ambient lighting, occlusion and eye movements, and internal (proximal) noise. Despite this variability in the incoming information, our perception is stable. Serial dependence, the behavioral attraction of current perceptual responses toward previously seen stimuli, may reveal a mechanism underlying stability: a spatiotemporally tuned operator that smooths over spurious fluctuations. The current study examined the neural underpinnings of serial dependence by recording the electroencephalographic (EEG) brain response of female and male human observers to prototypical objects (faces, cars, and houses) and morphs that mixed properties of two prototypes. Behavior was biased toward previously seen objects. Representational similarity analysis (RSA) revealed that responses evoked by visual objects contained information about the previous stimulus. The trace of previous representations in the response to the current object occurred immediately on object appearance, suggesting that serial dependence arises from a brain state or set that precedes processing of new input. However, the brain response to current visual objects was not representationally similar to the trace they leave on subsequent object representations. These results reveal that while past stimulus history influences current representations, this influence does not imply a shared neural code between the previous trial (memory) and the current trial (perception).

SIGNIFICANCE STATEMENT The perception of visual objects is pulled toward instances of that object seen in the recent past. The neural underpinnings of this serial dependence remain to be fully investigated. The present study examined electroencephalographic (EEG) responses to faces, cars, and houses, and ambiguous between-category morphs. With representational similarity analysis (RSA), we showed (1) object-specific neural patterns that differentiate the three categories; (2) that the response to the current object contains information about the previous object, mirroring behavioral serial dependence; (3) that the object-specific neural pattern about the past was different from that in the current response, revealing that while past stimulus history influences current representations, this does not imply a shared neural code between the previous trial (memory) and the current trial (perception).

由于环境照明、遮挡和眼球运动以及内部（近端）噪声等外部因素，世界上物体的视觉属性每时每刻都会发生波动。尽管传入的信息存在这种变化，但我们的感知是稳定的。序列依赖性，即当前感知反应对先前看到的刺激的行为吸引力，可能揭示稳定性的潜在机制：一个时空调谐的算子，可以平滑虚假波动。当前的研究通过记录女性和男性人类观察者对原型物体（面孔、汽车和房屋）以及混合两个原型属性的变形的脑电图（EEG）大脑反应，检查了序列依赖性的神经基础。行为偏向于以前见过的物体。表征相似性分析（RSA）显示，视觉对象引起的反应包含有关先前刺激的信息。对当前物体的反应中的先前表征的痕迹在物体出现时立即发生，这表明序列依赖性是由处理新输入之前的大脑状态或集合引起的。然而，大脑对当前视觉对象的反应与它们在后续对象表征中留下的痕迹并不相似。这些结果表明，虽然过去的刺激历史影响当前的表征，但这种影响并不意味着先前的试验（记忆）和当前的试验（感知）之间存在共享的神经代码。

意义陈述对视觉对象的感知被拉向最近看到的该对象的实例。这种序列依赖性的神经基础仍有待充分研究。本研究检查了对面孔、汽车和房屋的脑电图（EEG）反应，以及类别间模糊的变形。通过表征相似性分析（RSA），我们展示了（1）区分这三个类别的特定于对象的神经模式；(2) 对当前对象的响应包含有关前一个对象的信息，镜像行为串行依赖；（3）关于过去的特定于对象的神经模式与当前反应中的不同，这表明虽然过去的刺激历史影响当前的表征，但这并不意味着先前的尝试（记忆）和当前的尝试之间存在共享的神经代码试验（感知）。