Association of social isolation and smartphone use on cognitive functions

The number of socially isolated older adults has increased owing to the coronavirus disease pandemic, thus leading to a decrease in cognitive functions among this group. Smartphone use is expected to be a reasonable preventive measure against cognitive decline in this social context. Thus, this study aimed to investigate the influence of social isolation and smartphone use on cognitive functions in community-dwelling older adults.

We divided 4,601 community-dwelling older adults into four groups based on their levels of social isolation and smartphone use. Then, we conducted cognitive functions tests including a word list memory task, trail-making test, and symbol digit substitution task. Social isolation was defined when participants met two or more of the following measures: domestic isolation, less social contact, and social disengagement. We used an analysis of covariance adjusted by background information to measure between-group differences in levels of cognitive functions and social isolation. A linear regression model was used to analyze the association of standardized scores of cognitive function tests with smartphone use.

Smartphone users' scores of the symbol digit substitution task were superior compared with both non-users with social isolation and without. All cognitive functions were associated with smartphone use among non-socially and socially isolated participants. Socially isolated older adults showed an association only between trail making test- part A and smartphone use.

Smartphone use was associated with cognitive functions (memory, attentional function, executive function, and processing speed) even in socially isolated community-dwelling older adults.