Using TCD bilateral monitoring, we recorded mCBFV variations in 35 male and 35 female healthy, right-handed volunteers, classified as “young” (age range 21–40 years, n = 35) or “old”(age range 41–60 years, n = 35), performing four different cognitive tasks: encoding and recognition of Geometric Figures (GF), encoding and recall of Object Localization (OL) on a picture, encoding of a verbal Room Description (RD) and Arithmetic Skill (AS).
We found a significant right lateralization for the OL recall phase, and a significant left lateralization for RD and AS. When we took into consideration gender, age and performance, there was a strong effect of age on both OL encoding and recall phase, with significant right lateralization in young volunteers not seen in the older ones. No difference in gender was detected. We found a gender × performance interaction for RD, with poor performance females showing significant left lateralization.
According to our findings, hemispheric lateralization during memory encoding is material specific in both men and women, depending on the verbalizability of the material. mCBFV right lateralization during scene encoding and recall appears lost in older people, suggesting that healthy elderly could take advantage of mixed verbal and non-verbal strategies.