Ear-EEG Devices for the Assessment of Brain Activity: A Review

In-ear-centered electroencephalography (ear-EEG) has great potential for a possible transfer of brain monitoring technologies to real-life applications. Here, we conducted a systematic literature review of 96 studies published in the last few decades and found in several public databases (Pubmed, Scopus, Web of Science, Google Scholar, and Cochrane). These publications were further synthesized into six categories (sensor design and validation; event related potentials (ERPs); brain computer interface (BCI); sleep; epilepsy; computational modeling). Based on the current state-of-the-field in published literature, we demonstrated the versatility and wide variety of applications that ear-EEG technology enable, from detecting a user's physiological state in different conditions (drowsiness, sleep, or epilepsy) to a range of innovations in audiology and new BCIs.