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

Abstract

Over the past decades, functional near-infrared spectroscopy (fNIRS) has become a valuable tool in the online assessment of brain function in psychological and neuropsychiatric research. Recently, fNIRS has also been employed in the context of neurofeedback (NF), with pilot studies indicating that hemodynamic responses can be deliberately regulated and that neuroplastic changes occur over the course of several training sessions. This review article provides a comprehensive overview of the recent implementation and development of fNIRS as an NF tool; specifically, we will outline initial studies in healthy participants as well as children and adults with attention deficit hyperactivity disorder and describe new protocols aimed at reducing auditory verbal hallucinations (schizophrenic patients) and anxiety symptoms (patients with social anxiety disorder), respectively. Finally, we will discuss recent methodological developments and concerns as well as potential future perspectives. We conclude that fNIRS is a useful tool for conducting NF, especially in terms of multi-session training. However, methodological details need to be considered when designing fNIRS-based NF studies, and future protocols should aim at training broader network structures and implementing implicit training protocols. Finally, future studies should focus not only on (clinical) effects of fNIRS-based NF, but also on the underlying mechanisms and activity changes in extended brain networks.

The potential of functional near-infrared spectroscopy-based neurofeedback – a systematic review and recommendations for best practice

“…They concluded that fNIRS-neurofeedback training can enable participants to regulate their hemodynamic responses deliberately and that this training may induce changes in brain functions over time. Further, Ehlis et al (2018) conclude that if future studies confirmed initial findings, fNIRS-neurofeedback may become a complementary or even alternative treatment option for neuropsychiatric disorders.…”

“…Given the advantages of fNIRS over other neuroimaging modalities, this technique has been increasingly used as a tool for neurofeedback (Ehlis et al, 2018). During neurofeedback training, participants are trained to self-regulate their brain activity, generally with the ultimate goal of changing behavior or cognitive/emotional functions (for reviews see Paret et al, 2019;Sitaram et al, 2017;.…”

“…The available reviews are either not systematic or are selective (not covering all published fNIRSneurofeedback work). Some reviews focus more on general aspects of fNIRS-based brain-computer interfacing (e.g., Ehlis et al, 2018;Naseer and Hong, 2015;. For example, a recent review by Ehlis et al (2018) reviewed several of their own studies alongside a few other experiments.…”

“…Some reviews focus more on general aspects of fNIRS-based brain-computer interfacing (e.g., Ehlis et al, 2018;Naseer and Hong, 2015;. For example, a recent review by Ehlis et al (2018) reviewed several of their own studies alongside a few other experiments. They concluded that fNIRS-neurofeedback training can enable participants to regulate their hemodynamic responses deliberately and that this training may induce changes in brain functions over time.…”

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.…”