# Intelligent Virtual Reality and Augmented Reality Technologies: An Overview
## 4 Discussion
Particular emphasis was also put on human-computer interaction and the application of machine learning and deep learning. To better comprehend these topics, LDA, which is a probabilistic Bayesian model with a three-level hierarchical structure [63], was also used to identify topics within the document collection based on the title and abstract of the documents. Hence, using LDA, the following general topics and categories of interest emerged: \"Education/Learning/Training\", \"Healthcare and Medicine\", \"Generative artificial intelligence/Large language models\", \"Virtual worlds/Virtual avatars/Virtual assistants\", \"Human-computer interaction\", \"Machine learning/Deep learning/Neural networks\", \"Communication networks\", \"Industry\", \"Manufacturing\", \"E-commerce\", \"Entertainment\", \"Smart cities\", and \"New technologies\" (e.g., digital twins, blockchain, internet of things, etc.). These outcomes are in line with the results of the keywords and trends analysis and further validate the topics/areas identified. Furthermore, focusing on the total citations received within the document collection, the top documents relevant to the topic that explore the use of AI along with VR and/or AR were identified. The related outcomes are presented in Table 14 and are analyzed to provide an overview of the most impactful studies that currently guide this field of study. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Document**} & \multirow{2}{*}{**DOI**} & **Total** & **Total Citations** & **Normalized Total** \\  & & **Citations** & **per Year** & **Citations** \\ \hline
[81] & 10.1016/j.caeai.2022.100082 & 400 & 133.33 & 24.17 \\
[82] & 10.1038/s41467-021-25637-w & 262 & 65.5 & 16.13 \\
[83] & 10.1002/aisy.202100228 & 173 & 57.67 & 10.46 \\
[84] & 10.1109/OJCS.2022.3188249 & 166 & 55.33 & 10.03 \\
[85] & 10.1016/j.engappai.2022.105581 & 164 & 82 & 31.03 \\
[86] & 10.1038/s41591-019-0539-7 & 150 & 25 & 8.04 \\
[87] & 10.23919/ICACT53585.202.9728808 & 130 & 43.33 & 7.86 \\
[88] & 10.1016/j.isurg.2019.05.015 & 115 & 19.17 & 6.17 \\
[89] & 10.1080/00207543.2020.1859636 & 105 & 26.25 & 6.46 \\
[90] & 10.23919/jcin.2022.9815195 & 97 & 32.33 & 5.86 \\
[91] & 10.1007/978-3-319-93843-1\_12 & 97 & 13.71 & 11.05 \\ \hline \hline \end{tabular}
\end{table} 
Table 14: Documents with the highest number of citations. [PERSON] and [PERSON] [81] explored the metaverse through the lenses of AI. Their study went over the potential research issues, role, and definition of the metaverse and the role of AI within the metaverse. The study highlighted the potentials of the AI-enriched metaverse to support and improve the educational process. Additionally, it offered future research topics and directions and commented upon the wider use of the metaverse in the near future. [PERSON] et al. [82] focused on VR space and the use of AI to improve sign language recognition to enable bidirectional communication using haptic devices. In their study, they used a deep learning model for the recognition and translation of the sign language. Their outcomes revealed the significant benefits that can be yielded when integrating AI within VR environments to improve everyday life and communication. [PERSON] et al. [83] focused on the transition from AR and VR to the realization of digital twins using AI sensing technologies in the context of the internet of things. The study commented upon the role of AR, VR, and digital twins and highlighted the ability of using AI to design effective intelligent sensor systems. Finally, they pointed out the ability of AI to optimize processes and improve automation and of the metaverse and digital twins to bring about new opportunities for achieving a smarter future and commented on the existing challenges. In another study, [PERSON] et al. [84] examined the combination of AI and blockchain with the metaverse. The study focused on the unique characteristics and aspects of the metaverse and how they can be enhanced by using AI.