The VRCTI was developed to improve cognitive function. The intervention was designed that simulated schema of underwater world fish swimming. Each 1-hour session was typically divided into three parts: easy, medium and difficult, each with 4 different tasks, so there are 12 tasks/session in total. In some tasks, the VRCTI also distinguished between the real lure (e.g. a red triangle fish with a half-moon pattern) as well as unrelated lure items (i.e., blue square fish with polka dot pattern and other irrelevant items). The use of hardware elements for this study included visual (head-mounted display [HMD] in delivering the VR intervention), audio, and motor equipment.

The control group received usual care.

The VRCTI was developed to improve cognitive function. The intervention was designed that simulated schema of underwater world fish swimming. Each 1-hour session was typically divided into three parts: easy, medium and difficult, each with 4 different tasks, so there are 12 tasks/session in total. In some tasks, the VRCTI also distinguished between the real lure (e.g. a red triangle fish with a half-moon pattern) as well as unrelated lure items (i.e., blue square fish with polka dot pattern and other irrelevant items). The use of hardware elements for this study included visual (head-mounted display [HMD] in delivering the VR intervention), audio, and motor equipment.

The CASI evaluates global cognitive function using 9 cognitive domains: long-term memory, short-term memory, attention, mental manipulation, orientation, abstraction and judgment, language abilities, visual construction, and list-generating fluency. Typical administration time is about 20 minutes. The total score ranges from 0 to 100. A greater score demonstrates better global cognitive function.

General cognitive functioning was assessed with the Chinese version of the MMSE, which is a cognitive screening tool used to evaluate cognitive decline, screen for cognitive impairment, to evaluate the severity of the impairment, and to monitor cognitive change over time. The higher score indicates the better cognitive function.

The CDT-D has been widely used as a neuropsychological screening test in the detection of cognitive impairment in populations. The lower the patients' clock scores the more likely were patients to be classified as impaired in elderly outpatients.

The WHOQOL-BREF contains 28 items classified into the same 4 domains related to quality of life (physical health, psychological, social relationships and environment). All items were rated on a 5-point scale with a higher score indicating a higher quality of life.