[Ageing and working memory: the role of complexity and the type of information]

Although there is agreement that working memory in older adults diminished with age, there is still controversy whether this reduction occurs equally for all kind of information or it is more pronounced for a particular type of information.

To compare verbal working memory with visual and spatial working memory in young and older adults. These comparisons were examined at two levels of complexity.

Two experiments were conducted, in one of them subjects performed the verbal and visual tasks, and in the other the verbal and spatial tasks. Forty-two subjects participated in each experiment: 21 young adults and 21 older adults. The n-back task (1-back and 2-back) was used with letters, abstract figures and circles at different positions to evaluate verbal, visual and spatial working memory, respectively.

Older adults performed lower than young adults in the visual and spatial high difficult tasks. Working memory efficiency in the verbal task was equivalent in both groups, independently of the level of complexity; however, older adults' accuracy was lower in high complexity verbal task relative to the low complexity task.

The findings suggest that working memory deficits during aging do not depend on the type of information but on the amount of resources from the memory system that each type of information requires to be processed.