Validating the wearable MUSE headset for EEG spectral analysis and Frontal Alpha Asymmetry

Abstract

EEG power spectral density (PSD), the individual alpha frequency (IAF) and the frontal alpha asymmetry (FAA) are all EEG spectral measures that have been widely used to evaluate cognitive and attentional processes in experimental and clinical settings, and that can be used for real-world applications (e.g., remote EEG monitoring, brain-computer interfaces, neurofeedback, neuromodulation, etc.). Potential applications remain limited by the high cost, low mobility, and long preparation times associated with high-density EEG recording systems. Low-density wearable systems address these issues and can increase access to larger and diversified samples. The present study tested whether a low-cost, 4-channel wearable EEG system (the MUSE) could be used to quickly measure continuous EEG data, yielding similar frequency components compared to research a grade EEG system (the 64-channel BIOSEMI Active Two). We compare the spectral measures from MUSE EEG data referenced to mastoids to those from BIOSEMI EEG data with two different references for validation. A minimal amount of data was deliberately collected to test the feasibility for real-world applications (EEG setup and data collection being completed in under 5 min). We show that the MUSE can be used to examine power spectral density (PSD) in all frequency bands, the individual alpha frequency (IAF; i.e., peak alpha frequency and alpha center of gravity), and frontal alpha asymmetry. Furthermore, we observed satisfying internal consistency reliability in alpha power and asymmetry measures recorded with the MUSE. Estimating asymmetry on PAF and CoG frequencies did not yield significant advantages relative to the traditional method (whole alpha band). These findings should advance human neurophysiological monitoring using wearable neurotechnologies in large participant samples and increase the feasibility of their implementation in real-world settings.

Wearable System Based on Ultra-Thin Parylene C Tattoo Electrodes for EEG Recording

“…In Figure 4 , we have reported the raincloud plots which show the underlying distributions of the relative power spectral density values for the two systems when contrasting the two conditions (namely, eyes-closed and eyes-open resting state). These results clearly show that the proposed system is reliable in capturing the differences between the two tested experimental conditions since it does not differ from the Muse headset, a commercial EEG system that was previously validated using a 64-channel research-grade EEG system [ 37 ]. The same results were obtained on two more healthy subjects as reported in the Supplementary Information (Figure S1) , thus showing good results in terms of reliability.…”

“…Since the reference channel for the MUSE is located in correspondence to the Fpz position (which is not far from the frontal channels) and it has been shown that this choice may lead to asymmetric estimates compared with those evaluated using conventional montages [ 37 ], the frontal channel AF7 and AF8 were re-referenced to the TP9/TP10 mastoid electrodes. In order to evaluate if the recorded neural activity and the derived spectral measures obtained with the proposed system are reliable and able to capture the differences between the two experimental conditions (namely, eyes-closed and eyes-open resting-state), we tested whether these differences were comparable to those derived with the MUSE headset.…”

“…With the aim to maximize the portability and the comfort of the wearable acquisition system, a low number of dry and unobtrusive tattoo electrodes placed according to the 10–10 standard was chosen. The system was validated in a standard resting-state experiment where eyes-closed and eyes-open conditions were contrasted, and the resulting performance was compared to that of the commercial wearable system MUSE headset (InteraXon Inc., Toronto, ON, Canada) [ 37 , 38 , 39 ]. To mimic the configuration of this commercial system, five electrodes were positioned on the forehead and on the mastoid, respectively, on AF7, Fpz, AF8, TP9 and TP10, as shown in Figure 2 a.…”

Day‐to‐day individual alpha frequency variability measured by a mobile EEG device relates to anxiety

“…These findings are consistent with the high spectral correlations for TP9 and TP10 and low spectral correlations for AF7 and AF8 observed in this study. Even without electrode gel, many studies have utilized this device and claim to have found meaningful results (Cannard et al, 2021; Hashemi et al, 2016; Hawley et al, 2021; Hunkin et al, 2021; Krigolson et al, 2017). We determined that although using electrode gel may decrease the generalizability of the device, the stark improvement in the signal quality makes this a worthwhile trade‐off.…”

Trait mindful awareness predicts inter-brain coupling but not individual brain responses during naturalistic face-to-face interactions

“…As a neurofeedback tool, Muse and its accompanying app have been reported to be effective in reducing stress in breastcancer patients (Millstine et al, 2019), and improving well-being and attention (Bhayee et al, 2016). The validity of Muse-collected data was demonstrated in a couple of studies: an ERP study showed the pooled average of TP9 and TP10 electrodes successfully captured the N200, P300 responses (Krigolson et al, 2017); EEG data signatures such as power spectral density (PSD), the individual alpha frequency (IAF) and the frontal alpha asymmetry (FAA) measures computed from Muse data were consistent with those from a research-grade EEG system (Cannard et al, 2021); researchers successfully classified perceived mental stress level using the theta-band PSD from Muse (Arsalan et al, 2019). However, mindfulness-related EEG research using the Muse headset has generated mixed results.…”