Dissociating cognitive, behavioral and physiological stress-related responses through dorsolateral prefrontal cortex inhibition. (February 2021) - Era, Vanessa
Abstract: The left dorsolateral prefrontal cortex (dlPFC) has been implicated in the regulation of stress-related cognitive processes and physiological responses and is the principal target of noninvasive brain stimulation techniques applied to psychiatric conditions. However, existing studies are mostly correlational and causal evidence on the role of this region in mediating specific psychophysiological mechanisms underpinning stress-related responses are needed to make the application of such techniques more efficient. To fill this gap, this study used inhibitory continuous theta burst stimulation (cTBS) in healthy individuals to examine the extent to which activity of the left dlPFC is associated with cognitive (subjective focus on a tracking task), behavioral (reaction times and variability), and physiological responses (heart rate and its variability and cortisol level) following induction of perseverative cognition. Compared to sham and left ventral PreMotor area stimulation (as active control area), inhibition of left dlPFC determined sustained autonomic and neuroendocrine activation and increased the subjective perception of being task-focused, while not changing the behavioral and self-reported stress-related responses. Adopting a causative approach, we describe a role of left dlPFC in inhibitory control of the physiological stress-response associated to perseverative thinking. Highlights: The dorsolateral (dl) PFC is deputed to inhibitory control of the stress response. Transcranial magnetic stimulation (TMS) can inhibit the activity of the dlPFC. Inhibitory TMS over the left dlPFC increases levels of subjective focus on a tracking task. Inhibitory TMS over the left dlPFC leads to prolonged autonomic and cortisol activation. No concomitant changes at a behavioral and self-reported emotional level occurred.