EEGAgentBench

Benchmarking LLM Agents on Short- and Long-Horizon EEG Analysis

Huyu Wu1,2, Weining Weng1,2, Yuchen Liu1,2, Yiqiang Chen1,2, Yang Gu1,2,†
1Institute of Computing Technology, Chinese Academy of Sciences, 2University of Chinese Academy of Sciences
† Corresponding author
1,072
Instances
6
EEG Tasks
10
EEG Tools
29
LLM Agents
2s–23h
Signal Range
Model scale versus performance

Model scale versus Overall performance on EEGAgentBench. The benchmark reflects broad scaling trends while distinguishing frontier agents beyond raw parameter count and inference cost.

A Unified Benchmark for Agentic EEG Analysis

Electroencephalography (EEG) analysis is evolving from short-segment classification toward long-horizon interpretation that demands iterative evidence accumulation, multi-step reasoning, and coordinated use of specialized signal-processing tools. Although large language models (LLMs) have recently shown promise as autonomous agents for EEG analysis, existing EEG agentic evaluations remain fragmented, covering limited tasks over narrow temporal horizons with inconsistent protocols. To address this gap, we propose EEGAgentBench, a unified benchmark for systematically evaluating LLM agents on both short- and long-horizon EEG analysis. It spans six representative EEG applications ranging from knowledge question answering to sleep staging, with signal durations from 2 seconds to nearly 23 hours and prediction targets ranging from class labels to event intervals and epoch-level sequences. The benchmark provides 10 deterministic EEG analysis tools that expose only task-relevant measurements, so agents must select tools autonomously, accumulate evidence iteratively, and construct multi-step workflows. Benchmarking 29 frontier LLMs from 15 model families, we find that EEGAgentBench effectively distinguishes agent capabilities beyond model scale and inference cost, while revealing substantial limitations of current agents in long-horizon EEG analysis, particularly in sustained evidence accumulation and multi-step reasoning.

Six Tasks Across Three Capability Dimensions

Benchmark overview

Overview of the six EEGAgentBench tasks and the agent–environment interaction.

KnowledgeT1

EEG Knowledge QA

Four-choice medical questions on EEG & clinical neurophysiology.

Source: MedMCQA-EEG  ·  N: 38
Signal: No signal
Metrics: Accuracy

Short horizonT2

Artifact Identification

Decide clean vs. ocular (EOG) vs. muscle (EMG) contamination.

Source: EEGdenoiseNet  ·  N: 300
Signal: 2 s, 1 ch
Metrics: Accuracy, Macro-F1

Short horizonT3

Normal-vs-Epileptic

Screen a single-channel epoch as normal or epileptic.

Source: Bonn  ·  N: 188
Signal: 23.6 s, 1 ch
Metrics: Accuracy, Macro-F1

Short horizonT4

Dementia Cohort

Classify resting-state EEG as AD / FTD / HC cohort.

Source: ds004504  ·  N: 69
Signal: 5.1–21.5 min, 19 ch
Metrics: Accuracy, Macro-F1

Long horizonT5

Seizure Detection

Localize a variable number of seizure onset/offset intervals.

Source: CHB-MIT  ·  N: 280
Signal: 12.4 min–4.0 h, 18–32 ch
Metrics: Dice-S, Event-F1

Long horizonT6

Sleep Staging

Produce a full-night 30-s epoch AASM 5-class hypnogram.

Source: Sleep-EDFx  ·  N: 197
Signal: 5.7–23.0 h, 5–7 ch
Metrics: Macro-F1, Cohen's κ

Interactive, Tool-Based EEG Analysis

EEGAgentBench formulates EEG analysis as an interactive process between an agent and an EEG environment, following a ReAct-style multi-turn protocol. Instead of exposing raw waveforms, recordings are accessed exclusively through a unified tool interface. At each step, the agent may invoke an EEG analysis tool with user-defined arguments or terminate by submitting a final prediction. All tools perform deterministic analysis without task-specific classifiers or label information, so performance depends entirely on the agent's reasoning, evidence integration, and workflow construction.

The environment exposes 10 EEG analysis tools spanning recording metadata, signal-quality assessment, frequency- and time-domain analysis, windowed feature extraction, transient candidate detection, and cross-channel analysis. The same tool suite is shared across all signal tasks (T2–T6), letting agents build task-specific workflows without predefined pipelines.

Dataset construction

Two-stage benchmark construction: difficulty screening and deterministic class balancing (1,703 → 1,072 instances).

Tool use behavior

Tool-use behavior across the five signal tasks. Agents adapt tool choices to the task, and top models sustain far deeper analysis on long-horizon tasks.

Main Leaderboard

29 LLM agents evaluated on all 1,072 instances. Blue bold = best, italic = second best.

RankModelOverall ↑ T1T2 ArtifactT3 Screening T4 CohortT5 SeizureT6 Sleep
AccF1AccF1AccF1Acc Event-F1Dice-SF1κ
Proprietary models
1GPT-5.6-sol0.6310.8160.5990.6430.8980.8990.4290.4930.5490.4040.4920.488
4Grok-4.50.5180.7890.5630.6370.6200.6540.2390.3480.5220.3670.3720.277
13Claude-Opus-4.60.4630.8420.4980.5670.5430.6120.2940.3620.2890.3660.3120.204
7GPT-5.50.5000.7370.6510.6900.5430.6120.1940.3330.5300.4490.3470.263
21GPT-5.40.4380.6840.7300.7330.7900.7980.2050.3190.0690.0630.150-0.004
19Gemini-2.5-Pro0.4420.6840.5760.6100.4850.5690.2790.2900.2910.2990.3360.252
3Qwen3.7-Max0.5290.7630.7470.7700.9090.9100.2080.3190.3250.3050.2190.094
8Gemini-3.5-Flash0.4950.6840.5360.5900.7090.7230.3760.4640.3770.3780.2910.193
Open-weight models: above 1T parameters
18LongCat-20.4450.7370.5320.5570.7240.7390.2550.3480.2420.2500.1820.054
20DeepSeek-V4-Pro0.4390.6840.5600.6400.7260.7340.1940.3330.2750.2690.1940.081
10MiMo-V2.5-Pro0.4910.7630.7450.7470.6240.6600.2810.3910.3130.2610.2180.065
5Kimi-K2.60.5130.8420.6420.6700.7670.7770.2720.3190.3470.3410.2080.071
Open-weight models: 100B–1T parameters
17GLM-5.20.4550.8160.6290.7000.4900.5800.1630.3190.3290.3570.3040.205
12GLM-5.10.4670.7630.6360.6700.7040.7230.1980.3480.2650.3200.2360.114
14DeepSeek-V3.20.4600.7110.6310.6930.7760.7770.1630.3040.2710.2580.2070.075
2MiniMax-M30.5300.8160.6660.6830.7540.7550.3600.4200.3540.2700.2290.089
25ERNIE-4.5-VL-424B0.4020.7370.4510.4570.6540.6540.3910.4490.0340.0190.1460.037
6Qwen3.5-397B-A17B0.5010.7630.7860.7830.7110.7180.1930.3330.3700.3210.1850.037
9Hy30.4920.7630.7740.7770.6080.6490.3070.3910.2360.2430.2640.173
16DeepSeek-V4-Flash0.4590.7630.4950.5870.8050.8030.2220.3480.2840.3200.1850.047
24Mistral-Medium-3.50.4190.7370.5050.5800.5680.6280.2200.3480.2640.2740.2170.079
11Qwen3.5-122B-A10B0.4850.7110.7010.7100.6560.6760.3380.4200.2980.2500.2080.067
Open-weight models: 10–100B parameters
23Llama3.3-70B0.4290.8680.4520.4700.6530.6540.3240.4060.1040.0160.1730.023
15Qwen3.5-35B-A3B0.4590.7110.6220.6400.7020.7020.3130.3910.2480.2480.1610.035
22Qwen3.6-27B0.4330.6320.5420.6530.7130.7180.2320.3480.2940.3040.1840.059
29ERNIE-4.5-21B-A3B0.2280.5260.1670.3330.3010.3940.2200.2170.0000.0000.1510.010
Open-weight models: below 10B parameters
26Qwen3-8B0.3320.6320.2210.3470.4880.5210.2870.3620.1430.0360.2240.081
27Qwen3-4B0.2990.3950.4050.4170.5090.5480.2480.3040.0470.0140.1880.065
28Qwen3-1.7B0.2330.4210.2610.3470.3450.5050.2410.3190.0000.0000.131-0.040

Overall is the unweighted mean of T1 accuracy, Macro-F1 for T2–T4 and T6, and Event-F1 for T5.

Task score distributions

Task-level score distributions separate areas of model competition (T2, T3) from shared bottlenecks (T4, T6).

Cost versus performance

Estimated inference cost vs. Overall (19 models). Higher cost does not consistently yield better performance.

Long-horizon error analysis

Long-horizon error analysis: seizure miss vs. over-alarm trade-off (T5), representative hypnograms, and the decline of sleep-staging Macro-F1 as recordings lengthen (T6).

Agent Trajectories in Action

Real GPT-5.6 trajectories from EEGAgentBench. For every task we show a successful and a failed run; each turn is collapsed by default — click Expand to reveal the agent's full reasoning, tool call, and raw tool output.

BibTeX

@article{wu2025eegagentbench,
  title   = {EEGAgentBench: Benchmarking LLM Agents on Short- and Long-Horizon EEG Analysis},
  author  = {Wu, Huyu and Weng, Weining and Liu, Yuchen and Gu, Yang},
  journal = {arXiv preprint},
  year    = {2025}
}