## 3 Results
### Cognitive Enhancement  
The study \"Playing a P300-based BCI VR game leads to changes in cognitive functions of healthy adults\" examines how playing a virtual reality game controlled by a brain-computer interface based on the P300 signal can impact the cognitive functions of healthy adults. The study found that participants who engaged with the VR game exhibited improvements in attention and memory, suggesting that the combination of VR and BCI can lead to cognitive enhancements [63]. The article \"A dynamically optimized time-window length for SSVEP based hybrid BCI-VR system\" explores how dynamically adjusting the time-window length used for processing brain signals can improve the performance of a brain-computer Interface system designed for virtual reality applications. The researchers investigated an SSVEP-based hybrid BCI-VR system and found that dynamically optimizing the time-window length, rather than using a fixed length, resulted in both higher accuracy and faster information transfer rates. This dynamic optimization allows the system to adapt to the user's brain activity in real-time, leading to enhanced control and immersion in the VR environment. The findings from this study suggest that incorporating adaptive signal processing techniques can significantly enhance the effectiveness of BCI-VR systems for various applications, such as neurorehabilitation and user interaction in virtual worlds [8]. The article \"A comparative study of stereo-dependent SSVEP targets and their impact on VR-BCI performance\" explores the integration of steady-state visual evoked potential brain-computer interfaces with virtual reality technology. The researchers compare different SSVEP paradigms to investigate how planar and stereoscopic visual stimuli influence the characteristics of SSVEP signals. Notably, they introduce a novel method called 3D-Blink, which utilizes opacity inversion instead of the traditional luminance modulation. This approach has the potential to improve user comfort and leverage depth perception in VR-based BCI applications. By evaluating the performance and usability of these stereo-dependent SSVEP targets, the researchers aim to advance the development of more immersive and effective BCI-VR systems for various applications, such as neurorehabilitation and human-computer interaction in virtual environments [9]. There is a complex interaction observed between the use of VR and the quality of EEG data in VR-EEG systems, especially in brain-computer interface (BCI) applications. VR headsets can sometimes interfere with the precise electrode placement required for high-quality EEG readings, as they can interfere with scalp contact or apply pressure that affects signal acquisition. Consumer-grade EEG devices, such as the Emotiv headset, which are often chosen for their convenience and portability in VR environments, may lack the electrode precision necessary for tasks requiring highly accurate brainwave data, making some BCI applications less reliable. This is indeed a \"chicken and egg\" situation as VR increases the immersiveness and practicality of the BCI experience, but at the same time, it can compromise the quality of EEG data, favoring user convenience and flexibility over precision. In response, researchers are exploring specialized VR-EEG integration methods and adaptive signal processing techniques to strike a balance between maintaining EEG quality and creating an immersive, effective VR-BCI environment. This is a topic that has not been explored much but is worth further investigation. Our own research in this area and conclusions related to the shorter task execution time with VR, compared to experiments without VR, show that the selection of the right configuration of devices and software and paradigms is important both for the time of adjustment to the VR-BCI system and the time of execution of the appropriate tasks using them.