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bioRxiv · 10.64898/2026.06.28.735051

EEG biomarkers of reinforcement learning and motivation: A multi-task battery

Qiu, Z.·Wang, M.·Lu, H.·Abir, Y.·Zharmakhan, R.·Singh, N.·Poppe, M.·Degni, L.·Huys, Q. J.
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Abstract

Serotonin and dopamine make dissociable contributions to reinforcement learning (RL) sub-components, yet we lack neural biomarkers capable of detecting their differential effects. Here, we report the development of a five-task EEG battery designed to probe these dissociable RL mechanisms. Using a model-free analytical approach in healthy volunteers, we identify distinct neural markers across probabilistic instrumental learning, motivational vigour, Pavlovian-instrumental transfer, reversal learning, and a working memory-RL task. A centroparietal P300 tracked incremental learning across three paradigms and showed cross-task convergent validity. Readiness potentials and beta suppression indexed value-based motor preparation, while frontal theta captured Pavlovian-instrumental conflict. The largely independent pattern across markers supports the batterys capacity to detect selective pharmacological effects on distinct neural systems.

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Qiu, Z., Wang, M., Lu, H., Abir, Y., Zharmakhan, R., Singh, N., Poppe, M., Degni, L., Huys, Q. J.. 2026-07-02. EEG biomarkers of reinforcement learning and motivation: A multi-task battery. https://doi.org/10.64898/2026.06.28.735051

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