We investigated indexical variation as a variable that promotes second language (L2) vocabulary learning across language modalities. In three experiments, we presented Catalan Sign Language signs (Experiments 1a and 1b), pseudowords (Experiment 2), and English words (Experiment 3) to participants in three conditions that varied in the number of people who introduced these stimuli (one, three, or six people). We evaluated learning outcomes in two recall tasks: a picture-to-L2 naming task and a L2-to-L1 translation task. For the sign modality, indexical variation benefitted the immediate recall of signs in the translation task (Experiment 1a) and delayed recall after two weeks in the picture naming task (Experiment 1b). For the oral modality, we observed no effect when participants learned pseudowords (Experiment 2), but variability benefited recall in the translation task when participants learned English words (Experiment 3). We discuss these contrastive results, considering the influence of indexical variation in adult L2 sign and oral vocabulary learning.

中文翻译：

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多多益善？论索引变异对二语词汇学习的影响

我们研究了索引变异作为促进跨语言模式的第二语言（L2）词汇学习的变量。在三个实验中，我们在三种条件下向参与者展示了加泰罗尼亚手语符号（实验 1a 和 1b）、伪词（实验 2）和英语单词（实验 3），引入这些刺激的人数各不相同（一个、三个） ，或六人）。我们评估了两项回忆任务的学习成果：图片到 L2 命名任务和 L2 到 L1 翻译任务。对于符号模态，索引变化有利于翻译任务中符号的立即回忆（实验1a），以及图片命名任务中两周后的延迟回忆（实验1b）。对于口头形式，我们观察到参与者学习伪词时没有效果（实验 2），但当参与者学习英语单词时，可变性有利于翻译任务的回忆（实验 3）。我们讨论这些对比结果，考虑索引变化对成人 L2 手语和口语词汇学习的影响。