Posture Affects How Robots and Infants Map Words to Objects

For infants, the first problem in learning a word is to map the word to its referent; a second problem is to remember that mapping when the word and/or referent are again encountered. Recent infant studies suggest that spatial location plays a key role in how infants solve both problems. Here we provide a new theoretical model and new empirical evidence on how the body – and its momentary posture – may be central to these processes. The present study uses a name-object mapping task in which names are either encountered in the absence of their target (experiments 1–3, 6 & 7), or when their target is present but in a location previously associated with a foil (experiments 4, 5, 8 & 9). A humanoid robot model (experiments 1–5) is used to instantiate and test the hypothesis that body-centric spatial location, and thus the bodies’ momentary posture, is used to centrally bind the multimodal features of heard names and visual objects. The robot model is shown to replicate existing infant data and then to generate novel predictions, which are tested in new infant studies (experiments 6–9). Despite spatial location being task-irrelevant in this second set of experiments, infants use body-centric spatial contingency over temporal contingency to map the name to object. Both infants and the robot remember the name-object mapping even in new spatial locations. However, the robot model shows how this memory can emerge –not from separating bodily information from the word-object mapping as proposed in previous models of the role of space in word-object mapping – but through the body’s momentary disposition in space.对于婴儿而言，词汇学习的首要难题在于将词汇与其指称对象建立映射关系；其次，当词汇或指称对象再次出现时，婴儿需要牢记这一映射关系。近期的婴儿研究表明，空间位置在婴儿解决这两类难题的过程中发挥着关键作用。本研究提出了一套全新的理论模型与实证证据，用以阐释身体及其瞬时姿势如何成为上述认知过程的核心支撑。本研究采用词汇-客体映射任务，该任务中，词汇要么在目标客体未出现时呈现（实验1-3、6与7），要么在目标客体出现但处于先前与干扰刺激绑定的位置时呈现（实验4、5、8与9）。本研究使用人形机器人（humanoid robot）模型（实验1-5）来具象化并验证这一假说：以身体为中心的空间位置（即身体的瞬时姿势）是绑定听觉词汇与视觉客体多模态特征的核心机制。该机器人模型不仅能够复现已有的婴儿实验数据，还能生成全新的预测假设，并通过新的婴儿实验（实验6-9）对这些假设进行验证。尽管在第二组实验中空间位置属于任务无关变量，但婴儿仍优先采用以身体为中心的空间关联性而非时间关联性来建立词汇与客体的映射关系。无论是婴儿还是机器人模型，即便在全新的空间位置中，都能牢记词汇-客体的映射关系。不过，机器人模型揭示了这种记忆的产生机制：并非如以往关于空间在词汇-客体映射中作用的模型所提出的那样，将身体信息与词汇-客体映射相分离，而是源自身体在空间中的瞬时姿态状态。