ENGAGEMENT WITH CLOSE RELATIONSHIPS ENHANCES PARIETAL CONNECTIVITY DURING AUDITORY ENTRAINMENT IN OLDER ADULTS: AN EEG HYPERSCANNING STUDY

Introduction: Auditory entrainment may enhance working memory and recall in older adults. While previous studies have investigated its effects within the population, our study is the first to consider social relationships as a potential influencing factor. We hypothesized that engagement with close relationships could potentiate the effects of auditory entrainment by enhancing functional connectivity in older adults.
Methods: Twelve older adults (70.7 ± 1.2 years) participated in two randomized EEG hyperscanning recording sessions, each with either a close relationship dyad (n = 12, 64.0 ± 1.8 years) or a stranger (n = 12, 65.7 ± 2.0 years). Groups did not differ significantly in age (p =0.546). Each session included a 120-second 40 Hz auditory entrainment period and 30-second pre- and post-entrainment resting-state EEG recordings. Resting-state interbrain functional connectivity, assessed by Phase Lag Index (PLI), was compared between sessions.
Results: During auditory entrainment, 40 Hz PLI within the parietal lobe was significantly higher between close relationship dyads than between strangers. Specifically, the left parietal PLI was significantly higher in dyads (0.120 ± 0.005) than in strangers (0.107 ± 0.002, p = 0.029), and right parietal PLI showed a similar pattern (dyads: 0.133 ± 0.009; strangers_: 0.112 ± 0.002; p = 0.029).
Conclusions: These findings provide the first empirical evidence that social relationships may enhance the effects of auditory entrainment. Our study advances understanding of neural mechanisms underlying the dyad effect in older adults, supporting further investigation of social-based interventions for this population.