Source-Learned Reliance for Selective Test-Time Adaptation of Multimodal Time Series (CARAT)

Payal Mohapatra, Yueyuan Sui (equal), Haodong Yang, Benjamin Lundell, Stephen Xia, Qi Zhu (Arm Inc. / Northwestern)

Summary

Test-time adaptation for multimodal wearables when individual streams (wrist BVP/PPG, ACC, EDA, temp, chest ECG…) become noisy or drop out. During source training an asymmetric modality-dropout curriculum drops each modality in proportion to its windowed input-projection gradient norm; the terminal per-modality dropout rate is frozen as a reliance profile. At deployment a lightweight one-class detector (FITS reconstruction residuals + log-spectral distance vs.