Guiding transcranial brain stimulation by EEG/MEG to interact with ongoing brain activity and associated functions: A position paper

Abstract

Non-invasive transcranial brain stimulation (NTBS) techniques have a wide range of applications but also suffer from a number of limitations mainly related to poor specificity of intervention and variable effect size. These limitations motivated recent efforts to focus on the temporal dimension of NTBS with respect to the ongoing brain activity. Temporal patterns of ongoing neuronal activity, in particular brain oscillations and their fluctuations, can be traced with electro- or magnetoencephalography (EEG/MEG), to guide the timing as well as the stimulation settings of NTBS. These novel, online and offline EEG/MEG-guided NTBS-approaches are tailored to specifically interact with the underlying brain activity. Online EEG/MEG has been used to guide the timing of NTBS (i.e., when to stimulate): by taking into account instantaneous phase or power of oscillatory brain activity, NTBS can be aligned to fluctuations in excitability states. Moreover, offline EEG/MEG recordings prior to interventions can inform researchers and clinicians how to stimulate: by frequency-tuning NTBS to the oscillation of interest, intrinsic brain oscillations can be up- or down-regulated. In this paper, we provide an overview of existing approaches and ideas of EEG/MEG-guided interventions, and their promises and caveats. We point out potential future lines of research to address challenges.

Prefrontal gamma oscillations reflect ongoing pain intensity in chronic back pain patients

“…Future studies need to take potential muscle confounds into account, but might investigate the potential of prefrontal gamma activity as a marker of ongoing pain for the diagnosis and treatment of chronic pain (Davis et al, 2017), especially in the context of neurofeedback and neurostimulation treatment approaches (Jensen et al, 2014;Sitaram et al, 2017;Thut et al, 2017). Thus, they reveal a potential neurophysiological marker of ongoing pain, which could be measured relatively easily using EEG as a noninvasive and broadly available clinical tool.…”

“…Such brain markers of ongoing pain intensity are of particular interest as they constitute potential targets for pain treatment using approaches such as neurofeedback and neurostimulation (Jensen, Day, & Miro, 2014;Sitaram et al, 2017;Thut et al, 2017). Such brain markers of ongoing pain intensity are of particular interest as they constitute potential targets for pain treatment using approaches such as neurofeedback and neurostimulation (Jensen, Day, & Miro, 2014;Sitaram et al, 2017;Thut et al, 2017).…”

Driving working memory with frequency‐tuned noninvasive brain stimulation

“…Several studies have demonstrated an immediate behavioral effect, in addition to functional changes as revealed by concurrent MEG/EEG, caused by stimulation frequencies that match those of endogenously generated brain rhythms (see Refs. and ). Using otTCS/tACS, such effects have been reported in multiple cognitive domains such as memory/cognition (e.g., Refs.…”

“…However, as mentioned above, the results from HD‐tACS (or dual‐site tACS) studies need to be replicated with validated electrode montages to control the spatiotemporal properties of the stimulation (see Refs. and ). Notably, in a recent study, Kleinert et al .…”

“…This is suggested by recent studies that employed rhythmic transcranial stimulation protocols (such as otDCS, tACS, or rhythmic TMS) and identified the more functionally relevant frequencies of stimulation that aim to modulate cognitive functions (see Refs. for reviews). Rhythmic TMS and otDCS/tACS are complementary tools for influencing oscillatory brain activity.…”