Socially enriched environments linked to better memory and cognitive flexibility in aged rats

A new research paper was published in Volume 17, Issue 9 of Aging-US on August 22, 2025, titled, "The impact of long-term social housing on biconditional association task performance and neuron ensembles in the anterior cingulate cortex and the hippocampal CA3 region of aged rats."

The research team led by Anne M. Dankert from Providence College and University of North Carolina, Chapel Hill, showed that aged rats who lived in socially enriched environments throughout life retained better memory and cognitive flexibility than those housed alone. This study highlights the importance of social interaction in protecting the aging brain.

Cognitive decline, such as memory loss and reduced problem-solving ability, affects many people over the age of 65. While many factors contribute to age-related cognitive decline, this study suggests that one key factor may be surprisingly simple: long-term social connection. To explore how social interaction might influence memory performance and brain activity, the researchers designed a study using rats as a model for aging in humans.

"Cognitive decline and changes in neuronal activity are hallmarks of aging."

They compared three groups of rats: young adults, aged rats housed alone, and aged rats housed socially in groups. All groups had access to the same physical enrichment, such as exercise and stimulating objects, but only some experienced lifelong social companionship. The team tested these animals on a complex memory challenge known as the biconditional association task, which requires animals to make context-based decisions-an ability that typically declines with age.

The results showed that aged rats living in social groups performed just as well as young adults on the memory task, while those housed alone showed significant impairments. Socially housed rats also made fewer working memory errors and required less effort to complete cognitive tasks, suggesting not only better performance but more efficient brain function. These benefits were not observed in aged rats who received only environmental enrichment without social interaction.

Brain imaging revealed additional differences between the groups. Socially housed aged rats showed increased activity in the hippocampus, particularly in the CA3 region, which plays a key role in forming and separating memories. In contrast, aged rats that lived alone had lower activity in this region, which may explain their poorer performance. Interestingly, socially housed rats also showed reduced overactivity in the anterior cingulate cortex-a brain area involved in attention and decision-making-suggesting a more balanced and efficient neural response.

This research provides new insight into how lifelong social experiences shape brain health during aging. While earlier studies have shown that physical activity and cognitive stimulation help preserve cognitive function, this study identifies social interaction as an independent and powerful protective factor. The findings are consistent with human studies showing that older adults who remain socially active tend to experience slower cognitive decline and stronger brain function.

Overall, these results emphasize that brain aging is not inevitable but may be influenced by our social environments. This research suggests that fostering lifelong social connections could be a critical, low-cost strategy to protect memory and mental flexibility in older adults.