title: Age-related changes in short-interval intracortical facilitation and dexterity.
abstract: Functional changes in the primary motor cortex might contribute to age-related decline in fine motor control. We measured short-interval intracortical facilitation (SICF) in an intrinsic hand muscle with paired-pulse transcranial magnetic stimulation at interstimulus intervals (ISIs) of 1.5, 2.5, and 4.5 ms in young and old participants and examined its association with dexterity. We found age-related effects in SICF, with greater facilitation in old than young participants at the 1.5-ms ISI and greater facilitation in young than old participants at the 2.5-ms ISI. SICF at the 2.5-ms ISI was positively correlated with performance on a task that required coordinated and dextrous use of both hands, suggesting that this measure indicates a capacity for executing demanding manual tasks.
authors.affiliation: School of Psychology, The University of Western Australia, Crawley.
authors.forename: Jordana
authors.initials: J
authors.lastname: Clark
authors.forename: Andrea
authors.initials: A
authors.lastname: Loftus
authors.forename: Geoff
authors.initials: G
authors.lastname: Hammond
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006225:Hand / Q000294:innervation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D012044:Regression Analysis; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult