While a large body of research has focused on the effect of aging on false memory, there are to date only a few studies that addressed this question in the field of a particular kind of memory error, boundary extension (BE), which refers to the tendency to overestimate the expanse of a previously perceived scene. This research was conducted in an exploratory perspective and pursued the objective of investigating the cognitive mechanisms involved in this phenomenon, in both young and older adults. The performances in working memory and executive functioning tasks were correlated with those of a classic BE task. While young and older adults seem to extrapolate spatial layout in equivalent proportions, BE might be due to different mechanisms at different ages: while the essential determinant of BE would be executive functioning in young adults, some of our data suggest that it would be intellectual efficiency in the elderly.