Decoding user satisfaction during reading of pre-defined question–answer pairs: BCI approach using delta and gamma EEG
- 1Engineering Division, New York University Abu Dhabi , ,
- 2Bionics Research Center, Korea Institute of Science and Technology (KIST) , ,
Abstract
Introduction: The rapid proliferation of large language models (LLMs) has intensified the need for robust evaluation frameworks to align artificial intelligence (AI) behavior with human expectations. While current reinforcement learning from human feedback (RLHF) strategies heavily rely on explicit, post-hoc self-reports, these metrics are fundamentally limited by subjective biases and user non-compliance.
Methods: To address this, the current study presents a novel brain-computer interface (BCI) framework that systematically characterizes the continuous, implicit neural correlates of user satisfaction and dissatisfaction during a reading-based evaluative task involving pre-validated LLM-generated question-answer pairs. Sixty-four-channel electroencephalography (EEG) data were recorded from 30 participants while they read and evaluated various LLM-generated responses. To capture genuine subjective experiences, individual trials were relabeled based on post-trial 5-point Likert scale ratings into five distinct evaluative states, and spatiotemporal spectral analyses were performed. A ShallowFBCSPNet architecture was further used to evaluate single-trial classification between the very satisfied and very dissatisfied conditions under a subject-mixed cross-validation scheme.
Results: Spatiotemporal spectral analyses revealed distinct neural oscillatory dynamics that temporally dissociate satisfaction and dissatisfaction. When reading highly satisfactory responses, a pronounced, sustained enhancement of low-frequency delta power was observed within the bilateral frontotemporal areas during the middle (4–8 s) and late (8–12 s) reading intervals, indexing high-order cognitive consolidation and reward processing. Conversely, processing highly dissatisfactory responses led to a localized suppression of high-frequency gamma power in the right frontotemporal region during the early interval (0–4 s), reflecting an immediate affective appraisal and expectation violation. Utilizing the ShallowFBCSPNet architecture, the system successfully discriminated between the “very satisfied” and “very dissatisfied” states, achieving an average accuracy of 81% under a subject-mixed cross-validation scheme.
Discussion: These findings demonstrate that user evaluative states are encoded via distinct frequency-specific cortical networks over differing temporal windows. By bridging cognitive neuroscience and artificial intelligence, this study establishes the conceptual and empirical foundation for passive BCI-driven implicit feedback channels, laying groundwork toward future real-time paradigms for next-generation LLM alignment; the classification result should be interpreted as a feasibility demonstration rather than an estimate of real-world decoding accuracy.
Related
- ‘(m6)A’ stands for ‘autoimmunity’: reading, writing, and erasing RNA modifications during inflammation
- Goals Drive Adaptive Analysis of Linguistic Features During Reading
- Functional decoding reveals a hidden regulatory layer of the Salmonella transcriptome during infection
- Processing at Phrase Boundaries During Self-Paced Reading
- Executive and language systems competitively shape predictive processing during reading
BibTeX
@article{park2026decoding,
title = {{Decoding user satisfaction during reading of pre-defined question–answer pairs: BCI approach using delta and gamma EEG}},
author = {Wanjoo Park and Salma Mansour and Laehyun Kim and Mohamad Eid},
journal = {Frontiers in neuroscience},
year = {2026},
month = sep,
doi = {10.3389/fnins.2026.1934150},
url = {https://europepmc.org/article/PMC/PMC13662127},
note = {CC BY},
}
RIS
TY - JOUR
TI - Decoding user satisfaction during reading of pre-defined question–answer pairs: BCI approach using delta and gamma EEG
AU - Wanjoo Park
AU - Salma Mansour
AU - Laehyun Kim
AU - Mohamad Eid
PY - 2026
DA - 2026/09/30
JO - Frontiers in neuroscience
DO - 10.3389/fnins.2026.1934150
UR - https://europepmc.org/article/PMC/PMC13662127
AB - Introduction: The rapid proliferation of large language models (LLMs) has intensified the need for robust evaluation frameworks to align artificial intelligence (AI) behavior with human expectations. While current reinforcement learning from human feedback (RLHF) strategies heavily rely on explicit, post-hoc self-reports, these metrics are fundamentally limited by subjective biases and user non-compliance. Methods: To address this, the current study presents a novel brain-computer interface (BCI) framework that systematically characterizes the continuous, implicit neural correlates of user satisfaction and dissatisfaction during a reading-based evaluative task involving pre-validated LLM-generated question-answer pairs. Sixty-four-channel electroencephalography (EEG) data were recorded from 30 participants while they read and evaluated various LLM-generated responses. To capture genuine subjective experiences, individual trials were relabeled based on post-trial 5-point Likert scale ratings into five distinct evaluative states, and spatiotemporal spectral analyses were performed. A ShallowFBCSPNet architecture was further used to evaluate single-trial classification between the very satisfied and very dissatisfied conditions under a subject-mixed cross-validation scheme. Results: Spatiotemporal spectral analyses revealed distinct neural oscillatory dynamics that temporally dissociate satisfaction and dissatisfaction. When reading highly satisfactory responses, a pronounced, sustained enhancement of low-frequency delta power was observed within the bilateral frontotemporal areas during the middle (4–8 s) and late (8–12 s) reading intervals, indexing high-order cognitive consolidation and reward processing. Conversely, processing highly dissatisfactory responses led to a localized suppression of high-frequency gamma power in the right frontotemporal region during the early interval (0–4 s), reflecting an immediate affective appraisal and expectation violation. Utilizing the ShallowFBCSPNet architecture, the system successfully discriminated between the “very satisfied” and “very dissatisfied” states, achieving an average accuracy of 81% under a subject-mixed cross-validation scheme. Discussion: These findings demonstrate that user evaluative states are encoded via distinct frequency-specific cortical networks over differing temporal windows. By bridging cognitive neuroscience and artificial intelligence, this study establishes the conceptual and empirical foundation for passive BCI-driven implicit feedback channels, laying groundwork toward future real-time paradigms for next-generation LLM alignment; the classification result should be interpreted as a feasibility demonstration rather than an estimate of real-world decoding accuracy.
SN - 1662-4548
SN - 1662-453X
ER -