BCIwiki (bciwiki.com) — Researchers report that FRED, a principled EEG-fNIRS fusion framework for imagined handwriting decoding, reaches 0.7952 overall accuracy, while a modality audit finds fNIRS-only decoding at chance, according to a preprint posted to arXiv on August 4, 2026 that has not yet undergone peer review.
Imagined handwriting offers a temporally rich paradigm for non-invasive neural decoding, and EEG-fNIRS fusion promises complementary neural information, but fusion is typically heuristic and lacks principled treatment of frequency-band redundancy. FRED builds frequency-decorrelated temporal ensembles for imagined handwriting decoding. The ensemble reaches 0.8076/0.7242/0.7492 accuracy on the public/private/overall test partitions without test-set adaptation or output constraints, and the complete system reaches 0.8498/0.7718/0.7952, ranking fourth on the private split. The modality audit finds fNIRS-only decoding at chance (0.2511 overall), while adding fNIRS to EEG changes accuracy by only +0.0025.