The present study examined the effects of aging on the execution
of a bimanual coordination task in a classical phase
transition paradigm in which coordination patterns (inphase
and anti-phase) and movement frequency were manipulated.
Two groups of adults, the so-called young (average
age 26 years) and old (average age 71 years) participants,
performed both in-phase and anti-phase patterns at different
frequencies. As we expected variability of relative phase
was larger for older participants than for younger ones for
both the in-phase and the anti-phase coordination patterns.
Moreover, phase transitions occurred at lower frequencies
for older participants and more transitions were observed
for older than for younger participants. Although no specific
hypotheses were made about the prominent source(s)
of age-related changes in coordination dynamics (i.e., an alteration
in the coupling function and/or an increase of the
magnitude of noise), our results suggest that these changes
might result from increases in the (neural) noise to be found
in the (bimanual) action system.