Grit and the brain: spontaneous activity of the dorsomedial prefrontal cortex mediates the relationship between the trait grit and academic performance.

As a personality trait, grit involves the tendency to strive to achieve long-term goals with continual passion and perseverance and plays an extremely crucial role in personal achievement. However, the neural mechanisms of grit remain largely unknown. In this study, we aimed to explore the association between grit and the fractional amplitude of low-frequency fluctuations (fALFF) in 217 healthy adolescent students using resting-state functional magnetic resonance imaging (RS-fMRI). We found that an individual's grit was negatively related to the regional fALFF in the right dorsomedial prefrontal cortex (DMPFC), which is involved in self-regulation, planning, goal setting and maintenance, and counterfactual thinking for reflecting on past failures. The results persisted even after the effects of general intelligence and the 'big five' personality traits were adjusted for. More importantly, the fALFF of the right DMPFC played a mediating role in the association between grit and academic performance. Overall, these findings reveal regional fALFF as a neural basis of grit and highlight the right DMPFC as a neural link between grit and academic performance.