title: Age effects on the asymmetry of the motor system: evidence from cortical oscillatory activity.
abstract: Functional hemispheric asymmetry can be lost with aging. In this electroencephalographic study, we assessed hemispheric asymmetries in regulating motor responses by analyzing oscillatory brain activity during a go/nogo task in younger and older right-handed participants. Three conditions were embedded in the task: go, high-conflict and low-conflict nogo. The hand used to respond to go stimuli was varied block-wise. Independently of the go/nogo conditions and responding hand, young participants showed asymmetric desynchronizations in the mu (10 Hz) and beta (18-22 Hz) frequency bands that was stronger in the scalp sensorimotor region contralateral to the hand used for the go responses, while older adults showed a more symmetric pattern of desynchronization. These findings indicate that a loss of hemispheric asymmetry is a hallmark of the aging motor system, consistent with a decline of inter-hemispheric motor inhibition in normal aging.
authors.affiliation: International School for Advanced Studies (SISSA), Trieste, Italy. vallesi@sissa.it
authors.forename: Antonino
authors.initials: A
authors.lastname: Vallesi
authors.forename: Anthony R
authors.initials: AR
authors.lastname: McIntosh
authors.forename: Natasa
authors.initials: N
authors.lastname: Kovacevic
authors.forename: Sam C C
authors.initials: SC
authors.lastname: Chan
authors.forename: Donald T
authors.initials: DT
authors.lastname: Stuss
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D001683:Biological Clocks / Q000502:physiology*; D003344:Cortical Synchronization / Q000502:physiology; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology