## 1 Introduction
This enables developers to propose video games that offer both enjoyment and well-being during gameplay. However, the implications of the cognitive processes that occur while playing VR video games have been relatively under explored. Further research in this area could provide valuable insights into how VR gaming impacts cognitive functions, attention, and other psychological aspects. Understanding these effects will not only contribute to the development of more engaging and effective VR games but also help to harness the full potential of this technology for cognitive enhancement and well-being. Various studies link cognitive activity to the power of electroencephalogram (EEG) [17; 18; 19]. In [18], brain activity during a working memory task in humans was investigated. The researchers found that gamma waves are associated with the maintenance of visual representations, whereas alpha waves reflect functional inhibition. Gamma activity was linked to the retention of facial orientation (dorsal stream), whereas alpha waves were observed during the retention of facial identities (ventral stream). In [19], alpha oscillations in EEG were explored, along with their relevance to cognitive, psychomotor, psychoemotional, and physiological aspects of human life. According to [20], alpha oscillations (8-12 Hz) play a critical role in selective attention, suppressing irrelevant information in different sensory systems. As reviewed in [21], studies on event-related potentials (ERPs) in attention-deficit/hyperactivity disorder (AD/HD) are examined. Additionally, the review recommends further research on temporal processing and integrating EEG and ERP measures in future studies. The work in [22] investigates how video gaming experience affects the modulation of brain activity through brain-computer interfaces (BCIs). It was found that experienced gamers may exhibit enhanced sensorimotor learning and improved BCI control. However, the video gaming experience did not necessarily lead to a significant performance increase, but it resulted in faster learning for \"hardcore\" players. Two exploratory studies exposed the effects of the MUSE neurofeedback device based on EEG in mindfulness-based relaxation activities [23]. No significant differences were found in heart rate variability (HRV) between the group that used the device and the unassisted relaxation group. Study [24] investigated the effect of cognitive training on young and older adults using EEG. Although there were significant cognitive improvements, the individual alpha frequency (IAF) of the EEG did not change in either of the groups. The IAF is shown as a stable and relevant neurophysiological marker in [24; 25]. Frontal alpha asymmetry (FAA) was addressed in [26; 27]. The studies suggested that greater left frontal activity is related to sensitivity to behavioral activation, whereas the relationship with behavioral inhibition is complex and not fully explained by right frontal activity. In this research, we analyze the level of cognitive concentration induced by three categories of VR video games. However, a direct comparison with previous studies is not possible due to various factors, such as limited access to EEG databases, different cognitive stimulation (as they do not study VR video games), distinct video game categories (non-VR), and the use of different EEG-based neurofeedback devices, among other reasons. Three representative metrics used in the state of the art were selected to address this. Specifically, the power spectral density (PSD) of alpha waves in the 8 to 12 Hz frequency range is utilized to analyze the state of relaxation and focused cognitive attention. The degree of cognitive concentration is derived by calculating the individual alpha frequency (IAF) and frontal alpha asymmetry (FAA). Based on the conducted experiments and obtained results, it is demonstrated that exergames within the VR video game category stimulate a higher level of cognitive concentration in players.