State-dependent effects of prefrontal repetitive transcranial magnetic stimulation on emotional working memory.

BACKGROUND

A growing body of findings illustrates the importance of state-dependency in studies using brain stimulation.

OBJECTIVE

We aimed to investigate the effects of tDCS priming followed by rTMS applied over the right dorsolateral prefrontal cortex (DLPFC) on emotional working memory.

METHODS

In a randomized single-blind within-subjects design, participants performed an emotional 3-back task at baseline and after tDCS priming (anodal, cathodal) and subsequent low-frequency rTMS (active, sham) of the right DLPFC. Stimuli consisted of words related to the distinct emotion categories fear and anger as well as neutral words.

RESULTS

Task accuracy increased for fear-related words and decreased for neutral words across stimulation conditions. No general state-dependent effects of prefrontal rTMS on working memory were found. We further showed a detrimental effect of negative emotional content on working memory performance.

CONCLUSIONS

Our findings support a hemispheric lateralization of emotion processing by demonstrating that the withdrawal-related emotion fear is associated with the right DLPFC and contribute to clarifying the interaction between working memory and emotion.