# Integration Between Serious Games and EEG Signals:
## 1 Introduction
The raw brainwave data, represented as multi-channel EEG signals over time, is visualized to highlight the neural activity being recorded. After passing through a specialized signal processing module, these signals are sorted, filtered, and converted into commands or patterns that can be used. These patterns are converted into precise game commands, like movement or activities within the game environment, by feeding the processed outputs into a control system interface. Lastly, an interactive combat game serves as an example of how these directives are carried out in a gaming environment. Research linking serious games with EEG signals contemplates several objectives, among which the following stand out: (1) Test paradigms about BCI, (2) control video games, (3) design and implement neurofeedback games, (4) train or test video game users, (5) develop e-learning programs and medical applications (explore brain activities in certain disorders such as anxiety and autism), (6) activate EEG signals from serious games, (7) relate psychological components with physiological measurements, (8) compare traditional health equipment with low-cost equipment, and (9) test EEG signal analysis methods. Several review articles have examined and analyzed serious games using a BCI approach. [PERSON] et al. [PERSON] et al. (2015) present an investigation of BCI games according to the game genre (action, strategy, role play, adventure, sports, simulations, and puzzle games) to evaluate the suitability of game genres in the main BCI game implementations and introduce the term gameplay as the key aspect to consider in game development. [PERSON] et al. [PERSON] et al. (2015) examine neuroscientific studies on computer games, serious games, and virtual environments for learning processes, including attention, cognitive workload, sense of presence, and immersion. In the work of [PERSON] et al. [PERSON] et al. (2015), based on the review and search of literature carried out in the field of BCI games, they identify that BCI control paradigms that use EEG signals have been the main focus of research. Also, they conduct an opinion survey of researchers, developers, and users and propose three important elements in the expansion of the BCI games market: standards, playability, and appropriate integration. For their part, [PERSON] et al. [PERSON] et al. (2015) present an analysis of BCI research progress focusing on EEG-based video game applications, considering the extent of research in the field and the numerous benefits provided by such interdisciplinary research efforts. Considering the focus of the previous reviews, it is clear that they have provided useful and detailed information on the aspect they wish to highlight. BCI games are available in terms of BCI control paradigms, game genre, or in terms of applications. This review focuses on the experimental strategy implemented in integrating the serious games and EEG system. Motivated by the trends in serious games, the development of low-cost equipment for EEG signal acquisition, the increase in commercial devices for video game interaction, and applications involving serious games and EEG, this article aims to review and present technological solutions of existing works that link serious games and EEG signals. To this end, the method used for the literature search is described, definitions of serious game, BCI, and EEG signals are provided as previous concepts, and a taxonomy is proposed that allows the classification of the existing works and research into three different categories according to the experimental strategy implemented in the integration of the serious game and EEG system. For the work in these categories, details are presented on platforms and development languages (serious game), software tools (integration between serious game and EEG signals), and the number of test subjects, which allows for the integration of findings from different research projects. Finally, the main research challenges and future directions are discussed.