The role of DLPFC and trait anxiety in emotional memory retrieval. A rTMS study

Several studies agree to assign to the Prefrontal Cortex (PFC) a crucial role in integrating different aspects of the mind functioning. The PFC seems to be involved in cognition and memory and, secondly, in emotional regulation by managing the cognitive control over emotional stimuli and emotional behavior. Specifically, neuroimaging and Transcranial Magnetic Stimulation (TMS) studies showed an involvement of the DLPFC during Working Memory (WM), with a specific role in manipulation tasks, and possible consequences on long term memory (LTM) formation. Recent studies showed a further implication of the PFC in emotional memories on the Dorsolateral Prefrontal Cortex (DLPFC). Finally, the PFC seems to be also crucial to explain the relationship between some personality trait (such as anxiety) and the cognitive/emotive performance. The present rTMS study aims to investigate the interaction between memory, emotion and anxiety, focusing on the contribution of rTMS to increase performance in high anxious subjects. Subjects, were divided in two different groups depending on their anxiety level (high/low, STAI), were required to perform a task consisting in two experimental phases: an encoding phase, where some lists composed by emotional and non-emotional words were presented to the subjects; a retrieval phase, where the old stimuli and new stimuli were presented for a recognition performance. A rTMS stimulation was provided during the retrieval phase over the left DLPFC. We found that the rTMS stimulation over this area affects the memory retrieval of emotional material as a function of anxiety state condition. This result suggested that left DLPFC may be specifically involved in the memory retrieval of emotional information.