Loneliness modulates the neural dynamics of language processing in healthy older adults: evidence from event-related potentials

Loneliness, a distressing emotional response to perceived deficiencies in social interactions, has seen a marked increase in prevalence since the COVID-19 pandemic. While previous research has linked loneliness in older adults to affective disorders and cognitive decline, its impact on language comprehension-a crucial aspect of social interaction-remains underexplored. This study addresses this gap by examining the effects of loneliness on semantic retrieval in healthy older adults. Using event-related potentials, we measured participants' neural responses as they verified category membership across three conditions: high typicality, low typicality, and category violations. We found that loneliness was negatively correlated with an N400 amplitude reduction for low-typicality items compared to category violations. Moreover, individuals who reported a high level of loneliness exhibited attenuated and delayed N400 effects within more restricted time windows compared to their less lonely counterparts. These results indicate that loneliness impairs semantic memory retrieval in older adults, potentially compromising language comprehension and further exacerbating social isolation. This research highlights the detrimental impact of loneliness on linguistic abilities, which may contribute to a vicious cycle of increasing social isolation and deepening loneliness.