2026年PNPL競賽：LibriBrain100中的詞彙分類與高效跨受試者泛化

摘要

2025年PNPL競賽（Landau et al., 2025）的目標，是啟動一項為期多年的非侵入性語音解碼課程。該課程旨在由基礎任務逐步進展至實用腦機介面（BCI）所需的語言複雜度，並以語音偵測與音素分類任務揭開序幕。獲勝提交在各自任務上達到了95.6%和73.6%的F1-macro分數（Elvers et al., 2026），是極為重大的進展。這項成功建基於LibriBrain資料集（Özdogan et al., 2025）；該資料集是當時最大的受試者內MEG資料集，內含單一受試者約50小時的資料。然而，儘管受試者內的資料規模能驅動強勁的解碼表現，一個實用的BCI必須能從數分鐘而非數小時的資料，泛化至新使用者。 2026年PNPL競賽以LibriBrain100（Mantegna et al., 2026）回應此挑戰；這是擴充版的LibriBrain資料集，增加了32名受試者（每人約40分鐘），並納入更多受試者內資料（約80小時）。本屆競賽進一步將任務課程推進至詞彙分類，並設有兩個相輔相成的賽道：Deep賽道以規模化的受試者內詞彙分類為目標，追求最佳效能；Broad賽道則以跨受試者泛化為目標，逐步將受試者特定的微調資料量從約40分鐘降至約20分鐘，再降至約10分鐘——這個時長落在臨床可行的範圍內，也讓我們朝一個能夠為重度癱瘓患者恢復溝通能力的非侵入性BCI邁進了一步。

English

The ambition of the 2025 PNPL competition (Landau et al., 2025) was to launch a multi-year curriculum for non-invasive speech decoding. Designed to progress from foundational tasks toward the linguistic complexity required for a practical brain-computer interface (BCI), it set the stage with speech detection and phoneme classification tasks. Winning submissions reached F1-macro scores of 95.6% and 73.6% on the respective tasks (Elvers et al., 2026), highly significant advances. This success was built on the LibriBrain dataset (Özdogan et al., 2025), the largest within-subject MEG dataset recorded at the time with {sim}50 hours of data for one subject. However, while within-subject scale drives strong decoding performance, a practical BCI must generalise to new users from minutes of data, not hours. The 2026 PNPL competition responds to this challenge with LibriBrain100 (Mantegna et al., 2026), an extended LibriBrain dataset with 32 additional subjects ({sim}40 minutes each) plus even more within-subject data ({sim}80 hours). Advancing the curriculum of tasks to focus on word classification, two complementary tracks are presented in this competition: the Deep track targets within-subject word classification at scale, aiming at the best possible performance; the Broad track targets cross-subject generalisation, progressively reducing the amount of subject-specific fine-tuning data from {sim}40 to {sim}20 to {sim}10 minutes, a duration that falls within a clinically feasible range and brings us a step closer to a non-invasive BCI capable of restoring communication to people living with profound paralysis.