Inhibitory repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex modulates early affective processing

• Published in: NeuroImage (Orlando, Fla.) Vol. 101; pp. 193 - 203
• Main Authors: Zwanzger, Peter, Steinberg, Christian, Rehbein, Maimu Alissa, Bröckelmann, Ann-Kathrin, Dobel, Christian, Zavorotnyy, Maxim, Domschke, Katharina, Junghöfer, Markus
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-11-2014; Elsevier Limited
• Subjects: Adult; Amygdala; Anxiety; Cortico-limbic control; Facial Expression; Fear & phobias; Fear - physiology; Female; Humans; Inhibition (Psychology); Magnetoencephalography - methods; Male; Medical imaging; MEG; Neural networks; Pattern Recognition, Visual - physiology; Prefrontal Cortex - physiology; Studies; Time Factors; TMS; Transcranial Magnetic Stimulation - methods; Young Adult; Anxiety; TMS; Amygdala; Cortico-limbic control; MEG
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2014.07.003

The dorsolateral prefrontal cortex (dlPFC) has often been suggested as a key modulator of emotional stimulus appraisal and regulation. Therefore, in clinical trials, it is one of the most frequently targeted regions for non-invasive brain stimulation such as repetitive transcranial magnetic stimulation (rTMS). In spite of various encouraging reports that demonstrate beneficial effects of rTMS in anxiety disorders, psychophysiological studies exploring the underlying neural mechanisms are sparse. Here we investigated how inhibitory rTMS influences early affective processing when applied over the right dlPFC. Before and after rTMS or sham stimulation, subjects viewed faces with fearful or neutral expressions while whole-head magnetoencephalography (MEG) was recorded. Due to the disrupted functioning of the right dlPFC, visual processing in bilateral parietal, temporal, and occipital areas was amplified starting at around 90ms after stimulus onset. Moreover, increased fear-specific activation was found in the right TPJ area in a time-interval between 110 and 170ms. These neurophysiological effects were reflected in slowed reaction times for fearful, but not for neutral faces in a facial expression identification task while there was no such effect on a gender discrimination control task. Our study confirms the specific and important role of the dlPFC in regulation of early emotional attention and encourages future clinical research to use minimal invasive methods such as transcranial magnetic (TMS) or direct current stimulation (tDCS).
•We applied inhibitory rTMS brain stimulation to the right dlPFC in healthy controls.•Processing of emotional faces after real or sham stimulation was measured with MEG.•Brain stimulation led to amplified general and fear-specific face processing.•Cortical processing between 90 and 170ms after stimulus onset was affected.•Reduced inhibitory control resulted in slowed behavioral affect discrimination.