# Intelligent Virtual Reality and Augmented Reality Technologies: An Overview
## 1 Introduction  
Artificial intelligence (AI) is rapidly advancing as a field of study and due to its wide applicability and potentials, it is rapidly being integrated into different domains. AI refers to smart systems that simulate human intelligence and mimic the way they think, communicate, and act [1, 2, 3] as the development of these systems is driven by the human nervous system and humans' innate ability to learn, adapt, and reason [4, 5, 6]. Through the use of AI, intelligent systems [7, 8, 9], virtual agents and assistants [10, 11, 12], and multi-agent systems [13, 14, 15] can be created. Recent literature review studies have explored its use in various domains, such as education [16, 17, 18], industry [19, 20, 21], healthcare [22, 23, 24], business [25, 26, 27], smart cities [28, 29, 30], etc. The outcomes of these studies highlight the potential of AI to transform and enrich various sectors, which, in turn, reveals the need to further explore its capabilities to be used in combination with other novel technologies to further amplify its impact. potentially yield [10; 11; 31; 32]. Specifically, emphasis is being placed on the use of AI within augmented reality (AR), virtual reality (VR), and mixed reality (MR) environments. AR focuses on embedding interactive digital information and content in users' physical environment [33; 34] and is closer to the real world in the \"reality-virtuality continuum\" [35] while VR focuses on virtual environments that fully engulf and immerse users [36; 37; 38], thus separating them from the real environment and, as a result, it is closer to the virtual environment in the continuum. Additionally, the metaverse, which is characterized by its realistic virtual experiences and environments that constitute an extension of the real environment [39; 40; 41], is closely related to XR technologies and the creation of virtual worlds and environments with high levels of embodiment, interactivity, and persistence [42; 43]. As these technologies create new ways for users to interact, communicate, and experience events, they are increasingly being used in various settings and domains including education [44; 45; 46; 47], industry [48; 49; 50], healthcare [51; 52; 53], business [54; 55; 56], smart cities [57; 58; 59]. The studies highlighted the role of VR and AR in each domain and the benefits they can yield. The domains, although indicative, were selected to highlight the similarities in terms of application domains among AI, AR, and VR. The outcomes of the recent studies have revealed the positive impact that they can have in different domains. Hence, studies have also started to examine their combined use. However, although these technologies constitute established fields of studies on their own, their inter-relationship has yet to be examined in detail. As a result, there has not been any study that has examined the current state of the art regarding the use of AI within VR and AR environments and the metaverse. Examining the use of AI within extended reality (XR) environments can bring about new use cases as well as new opportunities. Additionally, by integrating AI, user-tracking, monitoring, and data processing can be improved and content and activities recommendation can be enhanced. Through this approach, more adaptive and personalized experiences, unique to each individual, can be created within immersive and interactive environments. Hence, it is vital to examine the convergence of these technologies. As this field of study is advancing, it is important to have a representation and mapping of the existing literature to identify emerging thematic areas and topics, limitations and challenges, and future research areas. Therefore, to bridge this gap, the aim of this study is to provide an overview and mapping of the existing literature about the convergence of AI with VR and AR technologies as well as to reveal future research directions.