Department of Psychology, Stanford University, Stanford CA 94305
Department of Psychology, Stanford University, Stanford CA 94305.
Proc Natl Acad Sci U S A. 2020 Dec 29;117(52):32970-32981. doi: 10.1073/pnas.2008852117. Epub 2020 Dec 10.
An important aspect of intelligence is the ability to adapt to a novel task without any direct experience (zero shot), based on its relationship to previous tasks. Humans can exhibit this cognitive flexibility. By contrast, models that achieve superhuman performance in specific tasks often fail to adapt to even slight task alterations. To address this, we propose a general computational framework for adapting to novel tasks based on their relationship to prior tasks. We begin by learning vector representations of tasks. To adapt to new tasks, we propose metamappings, higher-order tasks that transform basic task representations. We demonstrate the effectiveness of this framework across a wide variety of tasks and computational paradigms, ranging from regression to image classification and reinforcement learning. We compare to both human adaptability and language-based approaches to zero-shot learning. Across these domains, metamapping is successful, often achieving 80 to 90% performance, without any data, on a novel task, even when the new task directly contradicts prior experience. We further show that metamapping can not only generalize to new tasks via learned relationships, but can also generalize using novel relationships unseen during training. Finally, using metamapping as a starting point can dramatically accelerate later learning on a new task and reduce learning time and cumulative error substantially. Our results provide insight into a possible computational basis of intelligent adaptability and offer a possible framework for modeling cognitive flexibility and building more flexible artificial intelligence systems.
智能的一个重要方面是能够在没有任何直接经验(零样本)的情况下,根据与先前任务的关系,适应新任务。人类可以表现出这种认知灵活性。相比之下,在特定任务中表现出超人性能的模型往往无法适应甚至是稍微改变的任务。为了解决这个问题,我们提出了一种基于先前任务与新任务关系的通用适应新任务的计算框架。我们首先学习任务的向量表示。为了适应新任务,我们提出了元映射,即转换基本任务表示的高阶任务。我们在广泛的任务和计算范例中展示了这个框架的有效性,包括回归、图像分类和强化学习。我们将其与人类的适应性和基于语言的零样本学习方法进行了比较。在这些领域中,元映射是成功的,即使在新任务与先前经验直接矛盾的情况下,也可以在没有任何数据的情况下,在新任务上达到 80%到 90%的性能。我们进一步表明,元映射不仅可以通过学习到的关系进行泛化到新任务,还可以使用训练中未见过的新关系进行泛化。最后,使用元映射作为起点可以显著加速新任务上的后续学习,并大大减少学习时间和累积误差。我们的结果为智能适应性的可能计算基础提供了深入了解,并为建模认知灵活性和构建更灵活的人工智能系统提供了一个可能的框架。