Left parietal involvement in motion sickness susceptibility revealed by multimodal magnetic resonance imaging

Abstract

Susceptibility to motion sickness varies greatly across individuals. However, the neural mechanisms underlying this susceptibility remain largely unclear. To address this gap, the current study aimed to identify the neural correlates of motion sickness susceptibility using multimodal MRI. First, we compared resting-state functional connectivity between healthy individuals who were highly susceptible to motion sickness (N = 36) and age/sex-matched controls who showed low susceptibility (N = 36). Seed-based analysis revealed between-group differences in functional connectivity of core vestibular regions in the left posterior Sylvian fissure. A data-driven approach using intrinsic connectivity contrast found greater network centrality of the left intraparietal sulcus in high- rather than in low-susceptible individuals. Moreover, exploratory structural connectivity analysis uncovered an association between motion sickness susceptibility and white matter integrity in the left inferior fronto-occipital fasciculus. Taken together, our data indicate left parietal involvement in motion sickness susceptibility.

Keywords: MRI; conflict; motion sickness; resting state; vestibular; visual.

FIGURE 1

Motion sickness susceptibility in the study population. A total of 402 applicants completed the motion sickness susceptibility questionnaire (MSSQ) on the website (a). As a result of screening, 36 applicants with MSSQ scores >70 were enrolled as the motion sickness susceptible (MSS) group. Age/sex‐matched applicants with MSSQ scores <15 were enrolled as the motion sickness resistant (MSR) group. MSSQ scores were measured again on‐site in both the MSR and MSS groups to assess the test–retest reliability of the MSSQ (b)

FIGURE 2

Functional vestibular network involved in motion sickness susceptibility. The left posterior insular cortex showed greater negative connectivity with the medial occipital cortex, including the calcarine sulcus ($x=-2$, $y=-74$, $z=2$; $k=406$), in the motion sickness resistant (MSR) group than in the motion sickness susceptible (MSS) group (a). The left parieto‐insular vestibular cortex showed greater negative connectivity with the left superior frontal gyrus ($x=-18$, $y=20$, $z=46$; $k=270$) in the MSS group than in the MSR group (b)

FIGURE 3

Regional network centrality associated with motion sickness susceptibility. The left posterior intraparietal sulcus (IPS; $x=-26$, $y=-62$, $z=42$; $k=257$) showed greater network centrality (global functional connectivity) in the motion sickness resistant (MSR) group than in the motion sickness susceptible (MSS) group. This cluster was used as a seed region in the follow‐up seed‐to‐voxel functional connectivity analysis

FIGURE 4

White matter integrity associated with motion sickness susceptibility. The posterior part of the left inferior fronto‐occipital fasciculus ($x=-30$, $y=-70$, $z=1$; $k=243$) showed higher white matter integrity in the motion sickness susceptible (MSS) group than in the motion sickness resistant (MSR) group. The significant cluster is thickened for purposes of visualization (yellow‐red) and overlaid on the mean skeleton (green). L, R, A, and P denote left, right, anterior, and posterior, respectively