JMIR Publications

ABSTRACT

Background:

Aging can bring upon several effects that can hinder one’s quality of living. One of the effects is the decline in one’s ability to perform activities of daily living (ADLs), which is caused by the loss of hand function due to aging. To mitigate this, several virtual reality (VR)-based training/rehabilitation systems that utilize hand tracking were developed. Although these systems are effective and immersive and can promote motivation, they are mostly limited to providing a range of motion exercises. The addition of a force control component to the hand tracking of these systems could make them even more effective at improving/restoring hand function, as the majority of ADLs require a degree of force control.

Objective:

This study aimed to compare the effects of two VR input systems: regular hand tracking and the novel VR input system in this study, which incorporates force control to regular hand tracking on the brain activity of younger and older adults. Since the degree of cortical activity during a training/rehabilitation task is linked to better functional outcomes and neural plasticity.

Methods:

Twelve younger adults (ages 25.00±4.50) and 12 older adults (ages 73.00±3.6) were recruited to play a game specifically developed for this study using two VR input systems. Brain activity during gameplay was recorded using functional near-infrared spectroscopy (fNIRS) over the following cortical regions: prefrontal cortex (PFC), premotor cortex (PMC), supplementary motor area (SMA), and primary motor cortex (M1).

Results:

Compared to the regular hand-tracking system, adding a force control component increased average oxygenated hemoglobin (HbO) concentrations and decreased deoxygenated hemoglobin (HbR) concentrations in key brain regions. In young adults, these changes were observed in the right PMC and right M1. In older adults, higher HbO and lower HbR concentrations appeared in the rPFC, bilateral M1, and rSMA (HbR only). The force control component also led to more widespread activity across all regions of interest.

Conclusions:

The novel input system in this study can be utilized for improving/restoring hand function. The results of this study can be used as a reference for the development of better VR-based training/rehabilitation systems. Clinical Trial: The study in this paper was registered at ClinicalTrials.gov with the trial number NCT06412887.