Chronic Obstructive Pulmonary Disease (COPD) is a common but preventable disease that is associated with a chronic inflammatory response in the airways and lungs to noxious gases, often progressive, resulting in a persistent limitation of airflow. Chronic cough, dyspnea, and sputum production are the most common symptoms of the disease. Respiratory failure and decrease in physical activity seen in the later stages of the disease also negatively affect the participants' participation in daily life. COPD, which is an important health problem due to its increasing incidence, high prevalence, and associated social and economic costs, ranks fourth among the global causes of death. Cognitive and physical impairments are often associated with COPD prognosis. In the literature, a relationship was found between prefrontal cortex activity, exercise tolerance, and dyspnea perception of the individual. The prevalence of cognitive impairment in COPD ranges from 10 to 61%. Considering the effect of cognitive function on motor control, it is thought to affect physical performance. Studies have reported that prefrontal cortex oxygenation and perfusion increase with exercise. Depending on the positive effect of neuron metabolism, increases in cognitive and physical functions are observed. When examining the results of dual-task training and virtual reality applications in geriatric and neurological populations, positive effects on physical and cognitive functions have been demonstrated. Dual-task training causes an increase in cerebral perfusion and oxyhemoglobin as it requires more cognitive resources. Therefore, it is important for the investigators to create a program that includes cognitive performance rather than focusing only on motor performance in the rehabilitation of patients with COPD. Virtual reality applications are also widely used in many areas. A limited number of studies conducted on individuals with COPD have shown positive effects on physical performance. When examining the literature, it is seen that there is no study investigating the effects of virtual reality-assisted dual-task training in individuals with COPD. Based on this information, the investigators aim to evaluate the effect of virtual reality-supported dual-task training on cerebral, peripheral muscle, and respiratory muscle oxygenation in individuals with COPD using the fNIRS imaging method. The 30 individuals with COPD included in the study will be divided into two groups as intervention and control groups. In addition to the conventional physiotherapy and rehabilitation program, virtual reality-supported dual-task training will be given to the intervention group. In the control group, only the conventional physiotherapy and rehabilitation program will be applied. The treatment program will continue for 6 weeks, 3 days a week in both groups. Within the scope of the project, respiratory muscle strength, respiratory function, peripheral muscle strength, fatigue, balance, functional capacity, activity of daily living, cognitive level, and cerebral, peripheral, and respiratory muscle oxygenation of both groups will be evaluated before and after the intervention, and the effects of the intervention will be examined. For these purposes, the study will be the first in the literature to evaluate the effect of virtual reality-supported dual-task training in terms of cognitive functions and oxygenation and compare it with conventional physiotherapy applications. The study results will provide a basis for determining an optimal non-pharmacological treatment method to protect and improve physical and cognitive performance in individuals with COPD. In addition, the investigators believe that the study will have a social impact by helping to reduce mortality and morbidity rates in these patients and indirectly alleviate the burden on healthcare services. This project will contribute to the literature by providing a different perspective for clinical applications, as well as serving as a guide for future studies.