Modulation of Intrinsic Brain Connectivity by Implicit Electroencephalographic Neurofeedback

Abstract

Despite the increasing popularity of neurofeedback, its mechanisms of action are still poorly understood. This study aims to describe the processes underlying implicit electroencephalographic neurofeedback. Fifty-two healthy volunteers were randomly assigned to a single session of infra-low frequency neurofeedback or sham neurofeedback, with electrodes over the right middle temporal gyrus and the right inferior parietal lobule. They observed a moving rocket, the speed of which was modulated by the waveform derived from a band-limited infra-low frequency filter. Immediately before and after the session, the participants underwent a resting-state fMRI. Networkbased statistical analysis was applied, comparing post-vs. pre-session and real vs. sham neurofeedback conditions. As a result, two phenomena were observed. First, we described a brain circuit related to the implicit neurofeedback process itself, consisting of the lateral occipital cortex, right dorsolateral prefrontal cortex, left orbitofrontal cortex, right ventral striatum, and bilateral dorsal striatum. Second, we found increased connectivity between key regions of the salience, language, and visual networks, which is indicative of integration in sensory processing. Thus, it appears that a single session of implicit infra-low frequency electroencephalographic neurofeedback leads to significant changes in intrinsic brain connectivity.

Training the Conductor of the Brainwave Symphony: In Search of a Common Mechanism of Action for All Methods of Neurofeedback

“…Non-directive methods of neurofeedback, which have also been called implicit neurofeedback, do not rely on directions from a clinician to the subject, nor do they rely on the subject to consciously regulate their brain activity [84,85]. In fact, the subject does not need to do anything to receive the benefits of these methods of neurofeedback as they are entirely passive processes.…”

“…ILF), in which the target signal is continuous and the goal is not necessarily to modulate its activity [65]. Two general categories of methods have emerged in the field of neurofeedback, those that employ a directive, operant conditioning approach, which require explicit awareness and learning by the subject, and those that are non-directive in nature, employing a passive approach, which only require implicit learning of self-regulation of which the subject is likely unaware [84,85]. The directive methods are the most abundant and commonly used neurofeedback methods, and the theories behind them are the easiest to understand and explain.…”

“…Acquiring the neurofeedback, itself, requires dynamic shifts between taskpositive networks and the DMN, thus strengthening this shifting ability or network dynamics. These effects can be seen in emergent subnetworks that are present immediately after neurofeedback training that combine hubs from the SN, basal ganglia/reward network, and the visual network (presumably due to visual feedback) [85]. Furthermore, the specific brain location or brainwave that is the substrate for the feedback strengthens and stabilizes that brain activity or microstate [5,123].…”

Infra-Low Frequency Neurofeedback in Tension-Type Headache: A Cross-Over Sham-Controlled Study

“…Neurofeedback is a type of biofeedback utilizing brain signals and, at the same time, is it the least interventional type of neuromodulation, that relies on brain training rather than on direct stimulation. Neurofeedback targets the therapeutic modulation of a dysfunctional brain state, such as an imbalance in electroencephalographic (EEG) activity or altered intrinsic connectivity patterns ( Ros et al, 2013 ; Marzbani et al, 2016 ; Nicholson et al, 2016 ; Dobrushina et al, 2020 ). Despite the increasing number of studies examining neurofeedback in chronic pain ( Roy et al, 2020 ), only a few have focused on patients with headache.…”

Therapeutic Effect of Infra-Low-Frequency Neurofeedback Training on Children and Adolescents with ADHD

“…The general increase in spectral power of the ILF component of the EEG indicates that ILF neurofeedback training induces a modified baseline brain state. Another study using functional magnetic resonance imaging (fMRI) shows that even a single session of ILF neurofeedback leads to significant changes in connectivity in the brain [53].…”