Low diversity and low frequency of participation in leisure activities compromise working memory efficiency in young adults.

People perform leisure activities (LA) every day; pursuits that entail applying cognitive, physical and social abilities. As in old age, doing LA during early and middle adulthood is related to a reduced risk of dementias, probably by generating a cognitive reserve. As it is possible that a relation between doing LA and working memory (WM) efficiency exists in young adults, we assessed whether the diversity and frequency of LA are related to WM efficiency in this population. Ninety-three healthy young subjects solved the n-back task at two levels of difficulty (2, 3), and answered an LA questionnaire on the activities in which they had participated in the month prior to the experiment. Subjects were classified separately on their scores for (1) diversity (high/low) and (2) frequency (high/low) in order to test the relation between each variable and WM efficiency. Though no differences were found, a subsequent analysis of the average of diversity and frequency ratios of LA performance taken together-the diversity/frequency index-showed that low diversity plus low frequency was significantly associated with reduced WM efficiency at this age; results that suggest that frequent participation in diverse LA during youth is related to WM efficiency.

Involvement of the AATn polymorphism of the CNR1 gene in the efficiency of procedural learning in humans.

Procedural learning refers to the acquisition of motor skills and the practice that refines their performance. The striatum participates in this learning through a function regulated by endocannabinoid signaling and other systems. This study relates the efficiency in learning a procedural task with the AATn polymorphism of the CNR1 gene, which encodes for the CB1 receptor. The mirror-drawing star task was solved by 99 healthy young subjects in three trials. The sample was divided into high- and low-performance groups based on performance efficiency. AAT12/14 carriers were more frequent in the former group, while there were more AAT12/13 carriers in the latter, which also made more errors/min. Therefore, we characterized two efficiency phenotypes: high- vs. low-performers associated with the two AATn genotypes, AAT12/14 vs. AAT12/13. The findings suggest that AATn polymorphism modifies CNR1 translation, indicating a different modulation of CB1.