[Age differences in memorizing of sequence of movements of leading and subdominant hand]

Age-specific features of motor short-term memory were studied. Two groups of right-handed volunteers (18-25 and 35-60 years old) reproduced the memorized sequence of six movements by the right hand or by the left one. The mean values of erroneous movements are shown to be significantly higher in elder group, demonstrating the age-dependent reduction of motor short-term memory capacity. More detailed analysis of reproduction of separate elements of the sequence demonstrates that the age-dependent increasing of error value is significant for the leading right hand, but not for the subdominant left one. The data obtained are consistent with the evidences about age-dependent reduction of hemispheric asymmetry and about more pronounced reduction of the accuracy of the movements of the leading hand. According to the hypothesis about hemispheric specialization in coding of movement information (right hemisphere specialization on absolute positional coding, the left one--on relative vector coding, i.e. coding of the movements) the data suppose the age-dependent reduction of the left-hemisphere system of relative coding. The reduction of memory capacity apparently can be explained by the reduction of role of the left hemisphere in functioning of the short-term motor memory owing to age-dependent reduction of hemispheric asymmetry.