###### Abstract  
Background: The use of virtual reality (VR) has great potential for medical research and practice, which can help expand rehabilitation activities. This study aimed to evaluate the acceptability and feasibility of the original protocol VR multitasking cognitive training (CT) in both a healthy group and cardiac surgery patients. Methods: A specialized hardware and software complex was developed and tested on both a group of 25 practically healthy individuals, mean age 22.9 years (SD 2.57), and 25 cardiac surgery patients, mean age 62.2 years (SD 7.35). The participants were instructed to complete one session of multitasking CT within the VR complex. Psychometric testing and EEG studies were conducted. Results: All participants were highly accepting of the intended future use, attitude, and pleasure of the training. The healthy subjects demonstrated a statistically significant improvement in attention and spatial skills after VR (\(p<0.05\)). The EEG data revealed a significant increase in alpha power compared to pre-experiment levels (\(p<0.0001\)). The theta/alpha ratio significantly decreased after the VR multitasking CT as compared to the baseline (\(p<0.0001\)). Conclusions: The data obtained indicate that the original training protocol for multitasking CT using VR is acceptable and easy to use for both healthy individuals and cardiac surgery patients. cognitive training; virtual reality; system usability scale; EEG; alpha activity +
Footnote †: journal: Medical  
This procedure is not always complicated by stroke, but other consequences can lead to less pronounced, diffuse lesions that eventually lead to cognitive decline [10; 11]. There is an increase in the likelihood of postoperative cognitive dysfunction (POCD) in these patients [9]. POCD is a deterioration of higher-grade cognitive skills, attention, executive function, and memory [12]. Postoperative cognitive deficit manifestations can complicate the recovery process and decrease the efficacy of rehabilitation measures [13]. All of the above increases the financial burden on the healthcare system, which explains the need to find new approaches to cognitive recovery and prevent the progression of cognitive deficits. Cognitive rehabilitation aims to enhance cognitive reserve or stimulate plastic processes in the brain through various training methods. Recent studies have reported improved cognitive performance following combined physical and cognitive activities [14; 15; 16]. The simultaneous execution of cognitive and motor tasks or dual tasks requires significant cognitive control of attentional and executive functions [17]. Thus, the preliminary data show that a multimodal approach using cognitive training (CT) interventions can provide effective cognitive recovery. In the study by [PERSON] and colleagues, cognitive-motor training reduced the frequency of POCD during the early postoperative period of coronary surgery. The indicators of executive functions, attention, and short-term memory showed positive changes [18]. According to the authors, multitasking training can increase the involvement of different brain regions in the recovery process and slow down the progression of cognitive decline. The study used a computer-based version of the multitask training. However, new clinical practice options are available due to the development of emerging technologies. Virtual reality (VR) could be a possible approach for multimodal cognitive training. The manipulation of experimental parameters in VR apps has a great potential to develop new forms of cognitive intervention and treatment [19; 20]. Recent studies suggest that VR-based training interventions can be utilized to enhance well-being, cognition, and physical fitness in individuals with cognitive deficits [21; 22; 23]. In the study by [PERSON] et al. [21], the VR group demonstrated improvements in psychiatric symptoms, including apathy, affect for positive affect, and quality of life, when compared to the control group.