Age-related deterioration of coordinated interlimb behavior.

Younger and older participants performed two-limb coordination patterns of homologous (similar) and nonhomologous (dissimilar) effectors during 1:1 synchronization, according to the in-phase or anti-phase mode. The aim of the study was to examine age-related changes during the production of these basic movement patterns and their relative stability difference. The findings revealed that the aging process modulated the coordination dynamics as a function of effector system characteristics. Whereas the homologous system was resistant to age-related deficits, movements of the nonhomologous system showed coordinative degradation that was most apparent during execution of the anti-phase mode. The latter performance regression is argued to be an expression of age-dependent declines in cognitive regulation and afferent information processing. This implies that deterioration in coordinated behavior across the life span may be strongly task dependent because of a combined effect of cognitive and sensory components.