BCIwiki (bciwiki.com) — Mobile EEG is not a single, well-defined label. A participant might walk on a treadmill while the recording equipment stays in one place, carry a recording computer in a backpack, or wear a small head-mounted amplifier that logs directly to internal memory without a nearby phone or computer, according to Mentalab. All three setups can reasonably be called mobile EEG, but they allow different levels of freedom. That ambiguity led Bateson and colleagues to develop the Categorisation of Mobile EEG (CoME) framework in 2017.
The framework was built by examining 30 published EEG studies: 29 described as mobile or ambulatory, or involving movement during recording, plus one static EEG study as a reference point. The studies covered sitting, finger movements, treadmill walking, outdoor walking, cycling, stair climbing, carrying objects and treadmill running. Equipment varied too. Some systems stayed entirely off the body, others were carried at the waist or in a backpack, and some were mounted on the head and connected wirelessly to a computer or smartphone.
CoME describes a mobile EEG study with four parameters, summarized in a format such as (2D, 4P, 17S, 32C). Device mobility (D) describes where the EEG equipment sits and whether additional recording equipment is required, scored from 0 to 5: 0D means all equipment is off the body with the participant connected by cables; 2D means all equipment is carried at the waist; 4D means the system is head-mounted but requires a smartphone or tablet; 5D means the system is head-mounted and requires no additional recording equipment. None of the reviewed studies used a 5D setup, which represented what future systems might achieve.
Participant mobility (P) is also scored from 0 to 5 and describes what the person actually does: 0P means lying, sitting or standing still; 2P means constrained walking or cycling; 4P covers stair climbing, carrying objects while walking or constrained running; 5P means unconstrained running, vigorous exercise or sport. Keeping device and participant mobility separate is one of the framework's most useful ideas: a wearable EEG system can still be used in a resting-state experiment, producing a high D score and a 0P score.
System specification (S) combines four technical features, each scored 1 to 5, for a total of 4S to 20S. Channel count (C) is reported separately rather than converted into another ranked score, because more channels can help analyses such as spatial filtering and source reconstruction, but the right number depends on the research question and electrode placement. A focused study using 8 channels is not automatically weaker than one using 64 or more. Across the reviewed studies, device mobility ranged from 0D to 4D, participant mobility from 0P to 4P, and system specification from 6S to 17S. No study reached the theoretical maximum of (5D, 5P, 20S).
The authors stressed that CoME is not a product ranking, and a higher score does not necessarily mean a better system or a better study. A researcher may use an off-body computer for stimulus presentation and synchronization, or choose fewer channels to reduce preparation time or improve comfort. The framework reflects the technology and research priorities of 2017, and its specification score does not include features that matter today, such as integrated motion sensors, event synchronization, input range and impedance, access to raw data, and participant comfort. CoME is therefore best used to describe a study rather than as a current standard or a complete measure of EEG quality.
According to Mentalab, its Explore Pro fits the framework's 5D device-mobility category when the amplifier is head-mounted and records offline to internal memory without a connected phone or computer, a setup that was only a future possibility in 2017. The score changes with the workflow: using a smartphone for monitoring or recording brings it closer to 4D, and streaming to an off-body computer fits 3D. Participant mobility must still be assessed separately, so the same device used for resting-state recording scores 0P. The device offers 24-bit resolution, internal memory, wireless and offline recording, integrated motion sensing, and battery life of up to 10 hours depending on recording conditions, but those features do not mean it reaches CoME's complete (5D, 5P, 20S) maximum.
Published research shows how the framework applies. A 2025 study by Ledwidge and colleagues used a 16-channel Mentalab Explore+ system while 21 participants completed a cognitive task involving controlled overground jogging and directional sidesteps, comparing methods for removing motion artifacts and testing whether meaningful EEG components could be recovered during movement. In CoME terms, the participants performed substantial but controlled movement, fitting the logic of 4P rather than 5P, and the system streamed data to an off-body computer for recording and synchronization, making the setup closer to 3D than 5D. The researchers reported that Artifact Subspace Reconstruction and iCanClean improved the recovery of dipolar brain components under the conditions they tested, with iCanClean performing somewhat better, and the expected P300 congruency effect was identified after iCanClean processing. A separate 2023 study compared selected resting-state EEG spectral features recorded with Mentalab Explore and a clinical-grade EEG system in 23 participants, and tested whether the Mentalab measurements were similar across two sessions.