Comparing Brain Activity Between Sitting and Standing Positions during Optic Flow with Coinciding Auditory Cognitive Tasks

Abstract

Physical therapy intervention for people with vestibular disorders often includes optic flow stimulation. Such interventions can be performed with patients in either sitting or standing positions. Yet, little is known about how these positions affect brain activation during treatment. In this study, functional near-infrared spectroscopy (fNIRS) was used to investigate the reaction time and activation patterns of the prefrontal cortex (PFC) and temporoparietal junction VEST between sitting and standing conditions in the presence of both visual (optic flow) and cognitive (reaction time tasks) stimulation. 33 healthy adults participated in this two-visit study. In the first visit, participants were instructed to perform a series of reaction time tasks while sitting and experiencing optic flow at varying speeds through the HTC ViveTM virtual reality headset. In the second visit, participants performed the same tasks while standing. When compared with sitting, increased activation was observed in the left and right VEST for some of the standing trials. However, no statistical difference was found in the right or left PFC activation between sitting and standing positions when performing the reaction time tasks. These results suggest that, when compared to a sitting position, tasks performed in a standing position with optic flow stimulation will elicit greater VEST cortex activation, allow for multisensory integration training, and enhance positive outcomes after vestibular rehabilitation.

Keywords: virtual reality, optic flow, brain activity, dual-task

DOI: 10.54941/ahfe1004368