Age-Related Changes in Memorizing Sequences of Movements with the Dominant and Subdominant Hands

Abstract

The age-related characteristics of motor short-term memory on reproduction of a memorized sequence of six movements with the right or left hands were studied in two groups of subjects (right-handed, aged 18–25 and 35–60 years). The mean magnitudes of all movement errors were found to be significantly greater in the older subjects. More detailed analysis showed that the extent of errors increased with age only for the dominant right hand but not for the subdominant left hand. These data are consistent with reports of age-related decreases in interhemisphere asymmetry and more marked deterioration of motor precision with the dominant hand. Analysis of data in the framework of the hypothesis that the encoding of information relating to movements displays hemisphere specificity (specialization of the right hemisphere for absolute positional encoding and of the left for relative vectors, i.e., encoding of movements) provided grounds for suggesting that age is associated with deterioration of the functioning of the left-hemisphere relative encoding system.