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bioRxiv · 10.1101/2025.10.08.681181

Cortical Microstructural Variations Explain Individual Differences in Gamified Exploration-Exploitation Behaviours

Tyrer, A.·Nikolova, N.·Dubois, M.·Banellis, L.·Vejlo, M.·Hauser, T. U.·Allen, M. G.
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Abstract

The exploration-exploitation trade-off is ubiquitous in our everyday lives, and individuals display considerable variability in their preferred decision-making strategies. Most previous work pertaining to neural signatures of exploration is restricted to functional pathways. However, the specific contributions of cortical microarchitectures to high-level cognitive processes such as decision-making are as yet unknown. Here, we investigated the neuroanatomical foundations of inter-individual variability in decision-making strategies. To this end, 122 healthy participants completed a gamified multi-armed bandit paradigm aimed at teasing apart distinct exploration-exploitation decision strategies. We also collected whole-brain quantitative MRI maps indexing microstructural features of cortical myelination and iron content. Through computational modelling, we disentangled individual-specific exploration strategies, including value-free random exploration. Whole-brain regression analyses identified significant associations between value-free exploration and increased cortical myelination in right frontal brain areas with reported links to impulsivity. By elucidating the brain microstructural correlates of distinct exploration-exploitation strategies, we aimed to further our understanding of why individuals differ in their decision-making capabilities, and how decision-making may become aberrant in mental health conditions.

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Tyrer, A., Nikolova, N., Dubois, M., Banellis, L., Vejlo, M., Hauser, T. U., Allen, M. G.. 2025-10-09. Cortical Microstructural Variations Explain Individual Differences in Gamified Exploration-Exploitation Behaviours. https://doi.org/10.1101/2025.10.08.681181

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