This study utilised a finger force task to investigate the influence of attention and age on the occurrence of motor
overflow in the form of mirror movements in neurologically intact adults. Forty right-handed participants were
recruited from three age groups: 20–30 years, 40–50 years, and 60–70 years. Participants were required to maintain
a target force using both their index and middle fingers, representing 50% of their maximum strength capacity for
that hand. Attention was directed to a hand by activating a bone conduction vibrator attached to the small finger of
that hand. Based on Cabeza’s (2002) model of hemispheric asymmetry reduction in older adults, it was hypothesised
that mirror movements would increase with age. Furthermore, it was expected that when the attentional demands of
the task were increased, motor overflow occurrence would be exacerbated for the older adult group. The results
obtained provide support for the model, and qualified support for the hypothesis that increasing the attentional
demands of a task results in greater motor overflow. It is proposed that the association between mirror movements
and age observed in this study may result from an age-related increase in bihemispheric activation that occurs in
older adults, who, unlike younger adults, benefit from bihemispheric processing for task performance.