Mental imagery in a visuospatial working memory task and modulation of activation.

Ability to process information during a mental imagery task relying on visuospatial working memory and the advantages offered by the possibility of focusing the activation on specific items were examined in younger and older adults. The mental imagery task used for the study required participants to mentally move on a two-dimensional (55) or three-dimensional (333) matrix, while having to hold in memory either the whole pathway (WP condition) or just the final position reached (FP condition). The results revealed age-related differences in ability to modulate activation of visuospatial information. In particular, older adults, unlike the younger counterparts, did not benefit when the task allowed just part of the presented material to be considered. In particular, they drew less advantage from the three- dimensional matrix than the younger group. The findings are discussed in terms of the importance of processes reducing visuospatial working memory activation of irrelevant information and of the difficulties encountered by older adults in the modulation of activation.