title: Age-dependent visuomotor performance and white matter structure: a DTI study.
abstract: The Trail Making Test (TMT), which assesses motor performance, selective attention, working memory and cognitive flexibility is highly sensitive to age-related performance differences. However, the structural basis of this age-performance association is largely unknown. This DTI study examined the influence of white matter characteristics on the association between TMT performance (i.e., speed of processing) and age in a sample of 86 healthy, middle-aged subjects (mean age 27.9 years, range 18-55). Voxel-wise correlation yielded a significant negative association between FA in the body of the corpus callosum (CC) and TMT-A performance (i.e., time taken to complete the test). There was also a significant association between age and TMT-A performance. However, this association between age and TMT-A performance was neither mediated nor moderated by FA in the CC. Results suggest that fast motor performance is strongly dependent on individual white matter characteristics of the CC. This indicates that interindividual variations in white matter of the CC known to be relevant for interhemispheric motor signal transduction critically influence speed of motor processing. However, these interindividual variations do not explain the observed association between age and TMT performance.
authors.affiliation: Department of Psychiatry and Psychotherapy, Jena University Hospital, Philosophenweg 3, 07743 Jena, Germany. kathrin.koch@med.uni-jena.de
authors.forename: Kathrin
authors.initials: K
authors.lastname: Koch
authors.forename: Gerd
authors.initials: G
authors.lastname: Wagner
authors.forename: Claudia
authors.initials: C
authors.lastname: Schachtzabel
authors.forename: C Christoph
authors.initials: CC
authors.lastname: Schultz
authors.forename: Daniel
authors.initials: D
authors.lastname: Güllmar
authors.forename: Jürgen R
authors.initials: JR
authors.lastname: Reichenbach
authors.forename: Heinrich
authors.initials: H
authors.lastname: Sauer
authors.forename: Ralf G M
authors.initials: RG
authors.lastname: Schlösser
mesh_terms: D000328:Adult; D000367:Age Factors; D016880:Anisotropy; D003337:Corpus Callosum / Q000502:physiology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D014145:Trail Making Test