The influence of task characteristics on younger and older adult motor overflow

Q J Exp Psychol (Hove). 2009 Feb;62(2):239-47. doi: 10.1080/17470210802269217. Epub 2008 Aug 14.


This study investigated the influence of attentional and motor demands on motor overflow in 17 healthy young (18-35 years) and 17 older adults (60-80 years). Participants performed a finger pressing task by exerting either 33% or 66% of their maximal force output using their dominant or nondominant hand. Overflow was concurrently recorded in the passive hand. Attention was manipulated via a tactile stimulus presented to one or both hands for certain trials. Results showed that older adults exhibited greater overflow than young adults and that the effect of target force was exacerbated in older adults. Further, only older adult overflow was increased when tactile stimulation was directed to one or both hands. Increased overflow in older adults may result from bilateral cortical activation that is influenced by increased task demands. To perform comparatively to younger adults, older adults may compensate for age-related brain changes by recruiting an increased cortical network.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Aging / physiology*
  • Analysis of Variance
  • Attention / physiology*
  • Female
  • Functional Laterality / physiology*
  • Humans
  • Male
  • Middle Aged
  • Movement / physiology*
  • Muscle Contraction / physiology
  • Physical Stimulation
  • Psychomotor Performance / physiology*
  • Reaction Time / physiology
  • Task Performance and Analysis
  • Young Adult