EEG Foundation Models Fail to Capture Long-Range Temporal Correlations

A study published on arXiv tests whether EEG foundation models (FMs) retain long-range temporal correlations (LRTC) measured by the detrended-fluctuation-analysis (DFA) exponent of the alpha-band envelope. Five FMs (REVE, LaBraM, BENDR, CBraMod, BIOT) were probed on two out-of-distribution cohorts. None of the models represented LRTC in temporal order, revealing a spectral-temporal dissociation that undermines cross-population transfer. The findings challenge the assumption that embeddings from these models capture critical temporal dynamics.