Abstract
Normal functioning of the autonomic nervous system (ANS) is essential for daily life and many clinical populations present with the characteristic of cardiovascular dysregulation. A recent study by our laboratory group used a novel non-invasive treatment of infraslow neurofeedback (ISF-NF) targeting the posterior cingulate cortex (PCC), a key hub of the default mode network (DMN), which is known to regulate parasympathetic activity. They showed reduced feelings of craving, increased well-being and altered sleep patterns in women with food addiction, which all have known links to ANS functioning. It was hypothesised that ISF-NF in a healthy male cohort would modulate the cardiovascular ANS system via the increase of infraslow frequency (ISF) activity in the PCC. We tested this using a randomised, double-blind, placebo-controlled parallel study to test a battery of cardiovascular ANS measures. Participants received six sessions of either ISF-NF (n = 13) or placebo (n = 11) over a three-week period. There were no reported serious adverse effects. Additionally, no significant ISF activity changes over the whole brain or in current density the PCC after the last session or a week later; however, a trend in reduction of variation in the ISF activity of the ISF-NF group directly after the last training session (p = 0.063) was found. This study showed an increase in the ISF-NF group’s systolic blood pressure after the first session (p = 0.037) but not at the final session. The heart rate variance at the final session tended to be reduced in the ISF-NF group versus higher in the placebo group. This was the first study to compare the effects of ISF-NF in a healthy population and to study the effects of any neurofeedback treatment on the cardiovascular ANS system.