In everyday life, recognition decisions often have to be made for multiple objects simultaneously. In contrast, research on recognition memory has predominantly relied on single-item recognition paradigms. We present a first systematic investigation into the cognitive processes that differ between single-word and paired-word tests of recognition memory. In a single-word test, participants categorize previously presented words and new words as having been studied before (old) or not (new). In a paired-word test, however, the test words are randomly paired, and participants provide joint old–new categorizations of both words for each pair. Across two experiments (N = 170), we found better memory performance for words tested singly rather than in pairs and, more importantly, dependencies between the two single-word decisions implied by the paired-word test. We extended two popular model classes of single-item recognition to paired-word recognition, a discrete-state model and a continuous model. Both models attribute performance differences between single-word and paired-word recognition to differences in memory-evidence strength. Discrete-state models account for the dependencies in paired-word decisions in terms of dependencies in guessing. In contrast, continuous models map the dependencies on mnemonic (Experiment 1 & 2) as well as on decisional processes (Experiment 2). However, in both experiments, model comparison favored the discrete-state model, indicating that memory decisions for word pairs seem to be mediated by discrete states. Our work suggests that individuals tackle multiple-item recognition fundamentally differently from single-item recognition, and it provides both a behavioral and model-based paradigm for studying multiple-item recognition.

在日常生活中，通常必须同时对多个对象做出识别决策。相比之下，识别记忆的研究主要依赖于单项识别范式。我们对识别记忆的单个单词和配对单词测试之间的认知过程进行了首次系统研究。在单个单词测试中，参与者将之前出现的单词和新单词分类为以前学过的（旧的）或未学过的（新的）。然而，在配对单词测试中，测试单词是随机配对的，参与者为每对单词提供新旧联合分类。在两个实验中（ N = 170），我们发现单独测试的单词比成对测试的单词具有更好的记忆性能，更重要的是，配对单词测试暗示的两个单单词决策之间的依赖关系。我们将两个流行的单项识别模型类别扩展到配对词识别，即离散状态模型和连续模型。两种模型都将单词和配对词识别之间的性能差异归因于记忆证据强度的差异。离散状态模型根据猜测的依赖性来解释配对词决策中的依赖性。相比之下，连续模型映射了对助记符（实验 1 和 2）以及决策过程（实验 2）的依赖关系。然而，在这两个实验中，模型比较都倾向于离散状态模型，这表明单词对的记忆决策似乎是由离散状态调节的。我们的工作表明，个人处理多项目识别与单项目识别根本不同，并且它为研究多项目识别提供了基于行为和模型的范例。