Increasing cognitive reserve in older adults attending university enhances language capacity, but not executive function, episodic memory, or working memory: The Tasmanian Healthy Brain Project

Background: The strong link between educationand cognitive performance suggests that aperiod of education in later-life could enhancecognitive function. This is suggested as a nonpharmacologicalapproach to reduce age-relatedcognitive decline and protect against AD. Methods: Changes in episodic memory, workingmemory, executive function and language processingin older adults participating over four yearsin the Tasmanian Healthy Brain Project (THBP)were examined. The annual cognitive performanceof 459 participants enrolled in the THBP wereexamined. We compared a previously identifiedgroup of participants who undertook universitystudy and demonstrated increased cognitive reserve(CR) (intervention) against a group who did notengage in further education and did not display achange in CR (control). Results: Multiple group Latent Growth CurveModelling revealed no significant group differencesin the trajectory of scores in episodic memory,working memory or executive function between thetwo groups. However, the intervention group hadsignificantly better performance at baseline relativeto controls for language processing (Figure 1).Further, the intervention group displayed asignificant improvement in language processing overtime, with the control group remaining stable. Conclusions: In a group of older adults withimproved cognitive reserve resulting from attendinguniversity, we found that there is a commensurateimprovement in language processing capacityover time but no improvement was detected inepisodic memory, working memory or executivefunction. These results suggest that complex mentalstimulation that triggers improved cognitive reservealso enhances language processing capacity but noimprovement to other cognitive functions. Theseresults suggest that enhancement of CR in olderadults leads to improved crystallised cognitiveabilities but no improvement to fluid cognitiveabilities. It remains possible that over an extendedperiod of time differences may emerge in these othercognitive domains reflecting a decrease in the rateof age-related cognitive decline.