From ear to eye? No effect of transcutaneous vagus nerve stimulation on human pupil dilation: A report of three studies.

Transcutaneous stimulation of the auricular branch of the vagus nerve (tVNS) has been proposed as a treatment for a spectrum of physical and psychological disorders. One of the proposed working mechanisms of tVNS is a modulatory effect on the locus coeruleus - noradrenaline (LC-NA) network. We tested this hypothesis in humans in a series of three studies: one focusing on high trait worriers, and two in healthy populations.

Transcutaneous vagus nerve stimulation does not affect attention to fearful faces in high worriers.

People suffering from chronic worries pay excessive attention to emotional information. In this study we examined whether a reduced ability to inhibit attention from fearful faces (i.e.

The default response to uncertainty and the importance of perceived safety in anxiety and stress: An evolution-theoretical perspective.

From a combined neurobiological and evolution-theoretical perspective, the stress response is a subcortically subserved response to uncertainty that is not 'generated' but 'default': the stress response is 'always there' but as long as safety is perceived, the stress response is under tonic prefrontal inhibition, reflected by high vagally mediated heart rate variability. Uncertainty of safety leads to disinhibiting the default stress response, even in the absence of threat. Due to the stress response's survival value, this 'erring on the side of caution' is passed to us via our genes.

The effects of transcutaneous vagus nerve stimulation on conditioned fear extinction in humans.

A critical component of the treatment for anxiety disorders is the extinction of fear via repeated exposure to the feared stimulus. This process is strongly dependent on successful memory formation and consolidation. Stimulation of the vagus nerve enhances memory formation in both animals and humans.

Cardiac reactivity to and recovery from acute stress: temporal associations with implicit anxiety.

Excessive cardiac responses to stressful events are a risk factor for morbidity and mortality. Adverse cardiac responses are usually attributed to conscious negative stress and emotions. Yet, cardiac responses might also be affected by emotions that are not consciously reported.