Influence of Non-invasive Neurostimulation (Transcutaneous Vagus Nerve Stimulation) on 1. the Noradrenergic Release in the Brain and 2. a Neuropsychological Memory Task

The goal of this study is to investigate the influence of transcutaneous vagus nerve stimulation 1. on the noradrenergic system in the brain and 2. on memory, in healthy volunteers. Preclinical and clinical studies indicate that noradrenaline plays a role in the working mechanism of vagus nerve stimulation. This study will investigate if the effects of invasive vagus nerve stimulation can be replicated with transcutaneous vagus nerve stimulation. The release of noradrenaline in the brain will be measured non-invasively by the P300 component of event-related potentials in the electro-encephalogram (EEG) via an auditory oddball paradigm. Research to elucidate the working mechanism of non-invasive neurostimulation can help to identify subpopulations who will respond well to a treatment and can provide insights that could contribute to the optimalisation of the stimulation parameters, with as possible consequence a better clinical outcome. Some studies indicate that stimulation of the vagus nerve can optimally influence memory, possibly via the noradrenergic system. This study will investigate if the effects of invasive vagus nerve stimulation on memory can be replicated with transcutaneous vagus nerve stimulation. The influence of transcutaneous vagus nerve stimulation on memory will be measured via a neuropsychological memory task that investigates the ability to focus attention. The correlation between the performance on the memory task and the signal analysis of the auditory oddball task could give an indication about the underlying working mechanism of transcutaneous vagus nerve stimulation on memory. This will be the first step to investigate whether transcutaneous vagus nerve stimulation can be used as innovative intervention for cognitive decline.