Using virtual environments to assess visual perception judgements in patients with Parkinson's disease

Visual perception is an exceedingly critical concern in the daily lives of older people, particularly for determining traffic behaviors. In this study, two simulation experiments were conducted to determine the difference in visual perception judgement ability between healthy older individuals and patients with Parkinson's disease (PD) in simulated environments. The first experiment conducted in this study manipulated the sizes of different depth cues, reference objects, and vehicle size, and also requested participants to determine the distances between objects in different images to determine differences in depth perception between different groups. The second experiment simulates the participant in predicting the time to reach the front target in the driving state. In the experiment, different distances and different speeds are used to understand whether the participants of different groups will have differences in the time prediction. The results of the first experiment demonstrated that patients with PD exhibited significant depth perception degeneration in judging object distances. The second experiment revealed that when vehicles were traveling at high speeds, participants considerably underestimated vehicle speed. The results of this study demonstrate that patients with PD experience a degree of degeneration in terms of depth perception and perception of dynamic distance prediction. This result can assist patients with PD in understanding their visual perception degeneration and improving traffic awareness.