A Systematic Review and Multilevel Meta-Analysis of the McGurk Effect in Older and Younger Adults

Purpose: The McGurk effect is a well-established phenomenon to evaluate audiovisual integration. However, research on susceptibility to the McGurk effect in the aging population has yielded inconsistent findings. The present study examined group differences in the McGurk susceptibility between older and younger adults, as well as the factors influencing the magnitude of these differences. Method: A systematic search was conducted across four major electronic databases, focusing on empirical studies comparing susceptibility to the McGurk effect between older and younger groups. We employed a multilevel meta-analysis approach to synthesize effect sizes and identified potential moderators at both the sample level (i.e., age, hearing status, and cognitive status of older adults) and study level (i.e., auditory setting and task scoring method). Results: One study (containing two effect sizes) was excluded from the final analysis following a leave-one-out procedure. Based on the remaining 25 effect sizes from nine selected studies, a small-to-medium positive effect size ( g = 0.40) was observed, indicating greater susceptibility to the McGurk effect in older adults compared to younger participants. Among the moderators tested, only the cognitive status of older adults significantly moderated the observed heterogeneity, with variations in the cognitive status of older adults leading to significant changes in the magnitude of group differences in the McGurk susceptibility. None of the other moderators significantly explained variability in effect sizes. Conclusions: Our findings confirm an age-related difference in the McGurk susceptibility, with cognitive status emerging as a key moderator. However, given the limited number of studies included in this meta-analysis, the conclusion remains preliminary and should be interpreted with caution. To substantiate and expand upon these initial findings, future research should systematically investigate these moderating factors to inform targeted interventions and assistive technologies that enhance audiovisual integration and communication in the aging population. Supplemental Material: https://doi.org/10.23641/asha.31268749