The The Effect of Infraslow Frequency Neurofeedback on Autonomic Nervous System Function in Adults with Anxiety and Related Diseases


  • Karlien Balt, Msc Physiology Department of Human Physiology, Faculty of Health Sciences, University of Pretoria
  • Preet Du Toit, PhD Department of Human Physiology, Faculty of Health Sciences, University of Pretoria
  • Mark Llewellyn Smith, LCSW, BCN, QEEGD Neurofeedback Services
  • Charl Janse van Rensburg, MSc Mathematical Statistics Biostatics Unit, Medica Research Council Pretoria



neurofeedback, infraslow frequency, electroencephalogram, blood pressure, electromyogram, autonomic function


Peripheral body monitoring of autonomic nervous system (ANS) response has been routinely applied during infraslow fluctuation (ISF) neurofeedback training.  This study hypothesized that ISF training has a distinct physiological effect on an individual that can be revealed by measuring autonomic function with peripheral biofeedback metrics that included heart rate variability (HRV), muscle tension, skin temperature, skin conductance, heart rate, respiration rate, and blood pressure.  Methods.  Thirty adults between the ages of 18 and 55, primarily with anxiety, were randomized into two groups: 20 in the experimental group and 9 in the control group.  The experimental group completed 10 ISF neurofeedback training sessions while continuous monitoring of ANS changes was applied.  The same process was completed for a control group that received one-channel sensorimotor rhythm (SMR) neurofeedback training.  Results.  Significant changes were seen in the skin conductance (p < .0001), electromyography (p = .01), very low frequency (p = .004), low frequency of HRV (p = .05) and blood pressure (systolic change p = .049) in the experimental group.  No significant changes were seen in the control group.  Conclusion.  The study demonstrated that ISF neurofeedback training impacts the ANS as measured by peripheral biofeedback indicators.


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