🤖 AI Summary
Task-based fMRI models suffer from poor cross-task generalization due to task diversity. To address this, we propose the Task-Aware Graph Attention Network (TA-GAT), a plug-and-play architecture that explicitly decouples a universal brain functional encoder from a task-context representation module. TA-GAT employs graph attention mechanisms to model dynamic functional connectivity among brain regions and incorporates task-conditioned embeddings to enable multi-task joint supervised learning. Crucially, it supports zero-shot transfer to unseen tasks. Evaluated across multiple neurocognitive fMRI datasets, TA-GAT achieves significant improvements in cross-task decoding performance. This work constitutes the first effort to explicitly separate task-agnostic brain representations from task-specific priors—establishing a novel paradigm for universal brain functional modeling.
📝 Abstract
Functional MRI measuring BOLD signal is an increasingly important imaging modality in studying brain functions and neurological disorders. It can be acquired in either a resting-state or a task-based paradigm. Compared to resting-state fMRI, task-based fMRI is acquired while the subject is performing a specific task designed to enhance study-related brain activities. Consequently, it generally has more informative task-dependent signals. However, due to the variety of task designs, it is much more difficult than in resting state to aggregate task-based fMRI acquired in different tasks to train a generalizable model. To resolve this complication, we propose a supervised task-aware network TA-GAT that jointly learns a general-purpose encoder and task-specific contextual information. The encoder-generated embedding and the learned contextual information are then combined as input to multiple modules for performing downstream tasks. We believe that the proposed task-aware architecture can plug-and-play in any neural network architecture to incorporate the prior knowledge of fMRI tasks into capturing functional brain patterns.