Asynchronous involvement of VLPFC and DLPFC during negative emotion processing: An online transcranial magnetic stimulation study

The ventrolateral prefrontal cortex (VLPFC) and dorsolateral prefrontal cortex (DLPFC) have been found to play important roles in negative emotion processing. However, the specific time window of their involvement remains unknown. This study addressed this issue in three experiments using single-pulse transcranial magnetic stimulation (TMS). We found that TMS applied over the VLPFC at 400 ms after negative emotional exposure significantly enhanced negative feelings compared to the vertex condition. Furthermore, TMS applied over the DLPFC at both 0 ms and 600 ms after negative emotional exposure also resulted in deteriorated negative feelings. These findings provide potential evidence for the VLPFC-dependent semantic processing (∼400 ms) and the DLPFC-dependent attentional and cognitive control (∼0/600 ms) in negative emotion processing. The asynchronous involvement of these frontal cortices not only deepens our understanding of the neural mechanisms underlying negative emotion processing but also provides valuable temporal parameters for neurostimulation therapy targeting patients with mood disorders.