The Use of Frequency Analysis as a Complementary and Explanatory Element for Time Domain Analysis in Measurements of the Ability to Maintain Balance

Linking cognitive functioning and postural balance control through virtual reality environmental manipulations

Background

Dementia is becoming a relevant problem worldwide. A simple screening at an early stage will be important to detect the risk of developing dementia. Vestibular dysfunction is likely to be associated with cognitive impairment. Since head-mounted display (HMD) virtual reality (VR) technology has the potential to activate the vestibular function, assessing postural sway with visual stimulation using HMD VR technology could be potentially useful for dementia screening.

Objective

The purpose of this study is to evaluate the effect of HMD-based VR visual stimuli on posture in older adults and the relationship between the stimulated body sway behaviors and cognitive performance.

Method

Using a cross-sectional study design, we investigated the effect of an optokinetic design-based room with stripes (OKR) VR environment oscillating forwards and backwards at 23/60Hz. Center of pressure (COP) displacement was measured in older adults aged 65 years and over in the OKR VR environment. The frequency response of COP was compared to the cognitive performance of the Montreal Cognitive Assessment (MoCA).

Results

20 healthy older adults (70.4 ± 4.9 years; 27.2 ± 1.6 MoCA score) and 3 people with mild cognitive impairment (74.7 ± 4.0 years; 20.3 ± 2.1 MoCA score) were assessed. The results reveal that the oscillating OKR VR environment induced different postural sway in the anterior-posterior direction in the real world. Correlation analysis shows that the cognitive test score was associated with the frequency response of stimulated postural sway in the anterior-posterior direction (frequency Band 1 of 0−0.5Hz related to the visual and vestibular systems: r_s = 0.45, P = 0.03).

Conclusion

Outcomes would suggest that a potential link may emerge between cognition and posture when the HMD-based VR visual stimuli are applied. The simple screening of stimulated postural sway could explain cognitive functioning. Further studies are warranted to clarify the vestibular system and spatial cognitive function more specifically in the proposed assessment system.