Agentic Feature Selection via LLM for Epileptic Seizure Detection

Aizierjiang Aiersilan, Xiaodong Qu


Abstract
Automated epileptic seizure detection from electroencephalography (EEG) signals is a clinically important task in which feature selection is typically performed using purely statistical criteria. We investigate whether a small instruction-tuned large language model (LLM) can guide iterative feature selection for binary seizure detection on the Epileptic Seizure Recognition dataset (11{,}500 samples, 178 features). The LLM agent (Qwen2.5-1.5B-Instruct) receives five complementary statistical summaries and selects a feature subset through multi-round reasoning. The agent achieves 96.5\% accuracy and 0.911 F1 with 40 features, compared to 97.9\% accuracy and 0.946 F1 for the best full-feature baseline (SVM-RBF on 178 features). Critically, 39 of the agent’s 40 features coincide with the top-39 mutual-information features, and a deterministic Top-39 MI filter, evaluated by the same Random Forest classifier, attains the same 96.5\% accuracy and 0.911 F1. We therefore present this work as an empirical baseline: at the 1.5B-parameter scale, the LLM behaves close to a univariate MI ranker. We situate the result against the recent LLM-based feature selection literature and enumerate the ablations and multi-dataset extensions required to determine whether larger or domain-specialized LLMs add value beyond statistical filtering.
Anthology ID:
2026.bionlp-1.6
Volume:
BioNLP 2026
Month:
July
Year:
2026
Address:
San Diego, California
Editors:
Dina Demner-Fushman, Sophia Ananiadou, Kirk Roberts, Junichi Tsujii
Venues:
BioNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
64–74
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-1.6/
DOI:
Bibkey:
Cite (ACL):
Aizierjiang Aiersilan and Xiaodong Qu. 2026. Agentic Feature Selection via LLM for Epileptic Seizure Detection. In BioNLP 2026, pages 64–74, San Diego, California. Association for Computational Linguistics.
Cite (Informal):
Agentic Feature Selection via LLM for Epileptic Seizure Detection (Aiersilan & Qu, BioNLP 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-1.6.pdf