Human multimodal language understanding (MLU) is an indispensable component of expression analysis (e.g., sentiment or humor) from heterogeneous modalities, including visual postures, linguistic contents, and acoustic behaviours. Existing works invariably focus on designing sophisticated structures or fusion strategies to achieve impressive improvements. Unfortunately, they all suffer from the subject variation problem due to data distribution discrepancies among subjects. Concretely, MLU models are easily misled by distinct subjects with different expression customs and characteristics in the training data to learn subject-specific spurious correlations, limiting performance and generalizability across new subjects. Motivated by this observation, we introduce a recapitulative causal graph to formulate the MLU procedure and analyze the confounding effect of subjects. Then, we propose SuCI, a simple yet effective causal intervention module to disentangle the impact of subjects acting as unobserved confounders and achieve model training via true causal effects. As a plug-and-play component, SuCI can be widely applied to most methods that seek unbiased predictions. Comprehensive experiments on several MLU benchmarks clearly show the effectiveness of the proposed module.

Multidimensional Cockpit Perception (MCP) is an indispensable technology in assisted driving systems for modern vehicles, which requires joint recognition of the driver's emotional behaviors, traffic context, and vehicle condition. Despite promising progress in 2D to 3D neural networks, semantic discrepancies and intricate temporal dependencies among different signal streams still cause serious performance bottlenecks. To address these challenges, this paper proposes a Mutual Information-guided signal Graph fusion (MIG) framework for robust cockpit perception. MIG introduces an adaptive mutual information constraint to maximize the mutual information among different perceived signal streams, thus reinforcing the task-related feature semantic consistency. In addition, a signal graph fusion module is designed to capture intra- and inter-signal elemental correlations at a fine-grained level to learn joint multi-signal representations used for different downstream tasks. Systematic experiments on the MCP benchmark verify the effectiveness of the proposed framework and the necessity of our components.

As an emerging application in autonomous driving, multi-agent collaborative perception has recently received significant attention. Despite promising advances from previous efforts, several unavoidable challenges that cause performance bottlenecks remain, including the single-frame detection dilemma, communication redundancy, and defective collaboration process. To this end, we proposeSCOPE++, a versatile collaborative perception framework aggregating spatio-temporal information across on-road agents to tackle these issues. We introduce four components inSCOPE++for robust collaboration by seeking a reasonable trade-off between perception performance and communication bandwidth. First, we devise a context-aware information aggregation to capture valuable semantic cues in the temporal context and enhance the current local representation of the ego agent. Second, an exclusivity-aware sparse communication is introduced to filter perceptually unnecessary information from collaborators and transmit complementary features relative to the ego agent. Third, we present an importance-aware cross-agent collaboration to incorporate semantic representations of spatially critical locations across agents flexibly. Finally, a contribution-aware adaptive fusion is designed to integrate multi-source representations based on dynamic contributions. Our framework is evaluated on multiple LiDAR-based collaborative detection datasets in real-world and simulated scenarios, and comprehensive experiments show thatSCOPE++outperforms state-of-the-art methods on all datasets.

Driver distraction has become a significant cause of severe traffic accidents over the past decade. Despite the growing development of vision-driven driver monitoring systems, the lack of comprehensive perception datasets restricts road safety and traffic security. In this paper, we present an AssIstive Driving pErception dataset (AIDE) that considers context information both inside and outside the vehicle in naturalistic scenarios. AIDE facilitates holistic driver monitoring through three distinctive characteristics, including multi-view settings of driver and scene, multi-modal annotations of face, body, posture, and gesture, and four pragmatic task designs for driving understanding. To thoroughly explore AIDE, we provide experimental benchmarks on three kinds of baseline frameworks via extensive methods. Moreover, two fusion strategies are introduced to give new insights into learning effective multi-stream/modal representations. We also systematically investigate the importance and rationality of the key components in AIDE and benchmarks. The project link is https://github.com/ydk122024/AIDE.

Multi-agent collaborative perception has recently received widespread attention as an emerging application in driving scenarios. Despite the advancements in previous efforts, challenges remain due to various noises in the perception procedure, including communication redundancy, transmission delay, and collaboration heterogeneity. To tackle these issues, we propose \textit{How2comm}, a collaborative perception framework that seeks a trade-off between perception performance and communication bandwidth. Our novelties lie in three aspects. First, we devise a mutual information-aware communication mechanism to maximally sustain the informative features shared by collaborators. The spatial-channel filtering is adopted to perform effective feature sparsification for efficient communication. Second, we present a flow-guided delay compensation strategy to predict future characteristics from collaborators and eliminate feature misalignment due to temporal asynchrony. Ultimately, a pragmatic collaboration transformer is introduced to integrate holistic spatial semantics and temporal context clues among agents. Our framework is thoroughly evaluated on several LiDAR-based collaborative detection datasets in real-world and simulated scenarios. Comprehensive experiments demonstrate the superiority of How2comm and the effectiveness of all its vital components. The code will be released at https://github.com/ydk122024/How2comm.