Near-Infrared Spectroscopy-Based Frontal Lobe Neurofeedback Integrated in Virtual Reality Modulates Brain and Behavior in Highly Impulsive Adults

Abstract

Based on neurofeedback (NF) training as a neurocognitive treatment in attention-deficit/hyperactivity disorder (ADHD), we designed a randomized, controlled functional near-infrared spectroscopy (fNIRS) NF intervention embedded in an immersive virtual reality classroom in which participants learned to control overhead lighting with their dorsolateral prefrontal brain activation. We tested the efficacy of the intervention on healthy adults displaying high impulsivity as a sub-clinical population sharing common features with ADHD. Twenty participants, 10 in an experimental and 10 in a shoulder muscle-based electromyography control group, underwent eight training sessions across 2 weeks. Training was bookended by a pre- and post-test including go/no-go, n-back, and stop-signal tasks (SST). Results indicated a significant reduction in commission errors on the no-go task with a simultaneous increase in prefrontal oxygenated hemoglobin concentration for the experimental group, but not for the control group. Furthermore, the ability of the subjects to gain control over the feedback parameter correlated strongly with the reduction in commission errors for the experimental, but not for the control group, indicating the potential importance of learning feedback control in moderating behavioral outcomes. In addition, participants of the fNIRS group showed a reduction in reaction time variability on the SST. Results indicate a clear effect of our NF intervention in reducing impulsive behavior possibly via a strengthening of frontal lobe functioning. Virtual reality additions to conventional NF may be one way to improve the ecological validity and symptom-relevance of the training situation, hence positively affecting transfer of acquired skills to real life.

Near‐Infrared Spectroscopy as a New Tool for Neurofeedback Training: Applications in Psychiatry and Methodological Considerations

“…Specifically, we next implemented the above‐described prefrontal NF training in a virtual classroom environment, in order to allow children (and also young adults) to practice self‐regulation skills under more naturalistic conditions (i.e., with higher ecological validity) and facilitate the transfer of the training effects into everyday life (Blume et al, ). In a corresponding pilot study in a group of highly impulsive young adults, we focused on neurocognitive effects of the training and found a significant improvement in inhibitory function (reduced number of commission errors on a Go/NoGo task) as well as an increase in prefrontal oxygenation during response inhibition in the fNIRS training group; interestingly, similar effects were not observed in a control group that underwent an EMG‐based biofeedback training in the same virtual classroom (Hudak et al, ). In the same study, the obtained ability to self‐regulate (i.e., voluntarily control the feedback parameter reflecting prefrontal oxygenation) correlated with improvements in inhibitory control, suggesting a specific effect of prefrontal self‐regulation on the neurocognitive outcome.…”

Functionally disconnected: A look at how study design influences neurofeedback data and mechanisms in attention-deficit/hyperactivity disorder

“…With a CAR, distal effects due to volume conduction will necessarily taint the true nature of the local signal, although the global artifacts will be reduced, resulting in a higher signal to noise ratio [ 49 ]. In the realm of NIRS, many studies have used or use a CAR to reduce system-wide influences, such as respiration, heartbeat and motion artifacts, on the brain signal [ 8 , 9 , 34 , 50 ]. Three of these studies are NIRS-based NF studies dealing with ADHD or impulsivity.…”

“…These are all studies in which the CAR punished potentially helpful network activity. Nevertheless, Hudak et al [ 34 ] and Marx et al [ 9 ] realized beneficial results for highly impulsive and ADHD populations, respectively. It is therefore unlikely that the CAR diminished all network activity, but instead forced the network to operate differently.…”

“…The CAR is traditionally used in fNIRS experiments to remove global probeset artifacts such as head motion or arousal-related blood flow [ 33 ]. Furthermore, fNIRS and EEG NF experiments commonly employ the CAR to control such artifacts, as it is a computationally efficient method [ 8 , 9 , 34 – 37 ]. For each data point during the regulation phase, mean changes in O2Hb of four frontal channels per probeset were calculated.…”

Subject-independent decoding of affective states using functional near-infrared spectroscopy

“…fNIRS-based affective neurofeedback protocols were recently applied to healthy (Sakatani et al, 2013, Trambaiolli et al, 2018a and psychiatric populations (Ehlis et al, 2018), including patients with schizophrenia (Storchak et al, 2019), autism disorder (Liu et al, 2016), and attention-deficit/hyperactivity disorder (ADHD) (Marx et al, 2015, Hudak et al, 2017. However, all these protocols have subject-specific designs which require training blocks or calibration trials for every experimental session.…”