ABSTRACT
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.
Acknowledgements
The authors warmly thank Helene Intraub for her help on data analysis, as well as two anonymous reviewers whose comments and suggestions allowed them to improve this work.
Disclosure statement
No potential conflict of interest was reported by the authors.
Notes
1 Indeed, similar patterns of results emerged when the analyses were computed on the subsample of subjects who also participated in the cognitive and executive battery (N = 46). As the results were identical when the analyses were run on all trials and on higher-confidence trials, only the results observed with the latter are reported here. Moreover, for brevity, only the results of test pictures are exposed in detail. Thus, for CC and WW trials, a 2*2 mixed-design analysis of variance computed on participants mean boundary ratings with Age group as a between-subjects factor and Test type as a within-subject factor revealed an effect of Test type, F(1, 44) = 4.636, p = .037, η2p = .095, with greater BE for CC trials, no effect of Aging, F(1, 44) = 1.709, p = .198, η2p = .037, and no significant interaction between these two variables, F(1, 44) < 1, p = .637, η2p = .005. For distractors, the pattern of results was the same as with the whole sample of participants, with the exception of a significant interaction between Test type and Age group, F(1, 44) = 7.612, p = 0.008, η2p = .147, revealing that older participants evaluated the CW trials closer to 0 than the younger ones, t(44) = 2.942, p = 0. 005, d = 868.
2 The CW-WC difference (on absolute values) has to be interpreted in the same way as the boundary rating scale when it is used with CC and WW trials, negative values indicating BE, while positive values indicate BR. The more the value is different from 0, the higher the memory distortion is.
3 Note, however, that these two correlations were no longer significant when a Bonferroni correction for multiple comparisons was applied.