The aim of the study was to investigate whether age affects visual
memory retention across extended time intervals. In addition, we wanted
to study how memory capabilities across different time intervals are
related to the volume of different neuroanatomical structures (right
hippocampus, right cortex, right white matter). One test of recognition
(CVMT) and one test of recall (Rey-Osterrieth Complex Figure Test) were
administered, giving measures of immediate recognition/recall,
20–30 min recognition/recall, and recognition/recall at a
mean of 75 days. Volumetric measures of right hemisphere hippocampus,
cortex, and white matter were obtained through an automated labelling
procedure of MRI recordings. Results did not demonstrate a steeper rate
of forgetting for older participants when the retention intervals were
increased, indicating that older people have spared ability to retain
information in the long-term store. Differences in neuroanatomical
volumes could explain up to 36% of the variance in memory performance,
but were not significantly related to rates of forgetting. Cortical
volume and hippocampal volume were in some cases independent as
predictors of memory function. Generally, cortical volume was a better
predictor of recognition memory than hippocampal volume, while the 2
structures did not differ in their predictive power of recall
abilities. While neuroanatomical volumetric differences can explain
some of the differences in memory functioning between younger and older
persons, the hippocampus does not seem to be unique in this respect.
(JINS, 2005, 11, 2–15.)