  This paper addresses both the various EEG applications and the current EEG
market ecosystem propelled by machine learning. Increasingly available open
medical and health datasets using EEG encourage data-driven research with a
promise of improving neurology for patient care through knowledge discovery and
machine learning data science algorithm development. This effort leads to
various kinds of EEG developments and currently forms a new EEG market. This
paper attempts to do a comprehensive survey on the EEG market and covers the
six significant applications of EEG, including diagnosis/screening, drug
development, neuromarketing, daily health, metaverse, and age/disability
assistance. The highlight of this survey is on the compare and contrast between
the research field and the business market. Our survey points out the current
limitations of EEG and indicates the future direction of research and business
opportunity for every EEG application listed above. Based on our survey, more
research on machine learning-based EEG applications will lead to a more robust
EEG-related market. More companies will use the research technology and apply
it to real-life settings. As the EEG-related market grows, the EEG-related
devices will collect more EEG data, and there will be more EEG data available
for researchers to use in their study, coming back as a virtuous cycle. Our
market analysis indicates that research related to the use of EEG data and
machine learning in the six applications listed above points toward a clear
trend in the growth and development of the EEG ecosystem and machine learning
world.
