Jiang Yanru, Dale Rick
Department of Communication, University of California, Los Angeles, Los Angeles, California, United States of America.
PLoS Comput Biol. 2025 Feb 10;21(2):e1012286. doi: 10.1371/journal.pcbi.1012286. eCollection 2025 Feb.
There is an important challenge in systematically interpreting the internal representations of deep neural networks (DNNs). Existing techniques are often less effective for non-tabular tasks, or they primarily focus on qualitative, ad-hoc interpretations of models. In response, this study introduces a cognitive science-inspired, multi-dimensional quantification and visualization approach that captures two temporal dimensions of model learning: the "information-processing trajectory" and the "developmental trajectory." The former represents the influence of incoming signals on an agent's decision-making, while the latter conceptualizes the gradual improvement in an agent's performance throughout its lifespan. Tracking the learning curves of DNNs enables researchers to explicitly identify the model appropriateness of a given task, examine the properties of the underlying input signals, and assess the model's alignment (or lack thereof) with human learning experiences. To illustrate this method, we conducted 750 runs of simulations on two temporal tasks: gesture detection and sentence classification, showcasing its applicability across different types of deep learning tasks. Using four descriptive metrics to quantify the mapped learning curves-start, end - start, max, tmax-, we identified significant differences in learning patterns based on data sources and class distinctions (all p's < .0001), the prominent role of spatial semantics in gesture learning, and larger information gains in language learning. We highlight three key insights gained from mapping learning curves: non-monotonic progress, pairwise comparisons, and domain distinctions. We reflect on the theoretical implications of this method for cognitive processing, language models and representations from multiple modalities.
在系统地解释深度神经网络(DNN)的内部表示方面存在一个重要挑战。现有技术对于非表格任务通常效果较差,或者它们主要侧重于对模型进行定性的、临时的解释。作为回应,本研究引入了一种受认知科学启发的多维度量化和可视化方法,该方法捕捉了模型学习的两个时间维度:“信息处理轨迹”和“发展轨迹”。前者表示传入信号对智能体决策的影响,而后者将智能体在其整个生命周期内性能的逐渐提升概念化。跟踪DNN的学习曲线使研究人员能够明确确定给定任务的模型适用性,检查底层输入信号的属性,并评估模型与人类学习经验的一致性(或不一致性)。为了说明这种方法,我们在两个时间任务上进行了750次模拟:手势检测和句子分类,展示了其在不同类型深度学习任务中的适用性。使用四个描述性指标来量化映射的学习曲线——起始点、终点 - 起始点、最大值、最大值对应的时间点——我们基于数据源和类别差异确定了学习模式的显著差异(所有p值 <.0001),空间语义在手势学习中的突出作用,以及语言学习中更大的信息增益。我们强调了从映射学习曲线中获得的三个关键见解:非单调进展、成对比较和领域差异。我们思考了这种方法对认知处理、语言模型和多模态表示的理论意义。