The neurotransmitter dopamine plays a crucial role in human creative behaviour. Specifically, striatal dopamine seems to be associated with specific dimensions of divergent thinking performance, especially with categorical diversity (flexibility) of ideas. In experimental contexts, spontaneous Eye Blink Rate (sEBR) has been used as a proxy for striatal dopamine, and an inverted U-shape relationship between sEBR and flexibility has been demonstrated, such that a medium sEBR level pre- dicts highest flexibility levels. The present study aimed at carrying out further investigations about the relationship between sEBR and idea generation through divergent thinking, specifically focusing on the relationship between idea originality and dopamine level, since originality is a key element for creativity. We asked 80 participants, whose sEBR at rest was meas- ured, to perform an Alternative Uses Task (AUT) to measure their divergent thinking performance. Results revealed that the relationship between sEBR and originality, as measured through subjective ratings of external raters, followed an inverted U-shape function with medium sEBR being associated with highest originality scores. Moreover, and most importantly, we demonstrated that sEBR predicted originality through the mediation of flexibility. Our results provide further insights on the possible role of dopamine on divergent thinking performance, demonstrating that an adequate dopamine level may facilitate the generation of original ideas through the exploration of diverse conceptual categories (higher flexibility).
