Combining hierarchical drift-diffusion model and event-related potentials to reveal how do natural sounds nudge green product purchases

Sound is one of the important environmental factors that influence individuals' decision-making. However, it is still unclear whether and how natural sounds nudge green product purchases. This study proposes an extension of the Stimulus-Organism-Response (S-O-R) framework, suggesting that natural sounds increase early attentional congruency associated with green products, thereby promoting individuals' green product purchases. To test our theory, we conducted an experiment employing a hierarchical drift-diffusion model (HDDM) and utilized an event-related potentials (ERP) method. Results showed that natural sounds not only increased the purchase rate for green products but also enhanced drift rate in favor of purchasing green products. Additionally, consumers also exhibited a reduced frontal early P2 wave (150-230ms) in response to green products under natural sounds, indicating that natural sounds increased the early attentional congruency associated with green products. More importantly, neural correlates of early attentional congruency meditated the nudge effect of natural sounds on purchase rate and drift rate for green products. This study contributes to the neural understanding of how natural sounds influence green product purchases and provides actionable implications for market managers to design the green products sales environments.