TY - JOUR
T1 - Cognitive Processing Speed in Older Adults
T2 - Relationship with White Matter Integrity
AU - Kerchner, Geoffrey A.
AU - Racine, Caroline A.
AU - Hale, Sandra
AU - Wilheim, Reva
AU - Laluz, Victor
AU - Miller, Bruce L.
AU - Kramer, Joel H.
PY - 2012/11/21
Y1 - 2012/11/21
N2 - Cognitive processing slows with age. We sought to determine the importance of white matter integrity, assessed by diffusion tensor imaging (DTI), at influencing cognitive processing speed among normal older adults, assessed using a novel battery of computerized, non-verbal, choice reaction time tasks. We studied 131 cognitively normal adults aged 55-87 using a cross-sectional design. Each participant underwent our test battery, as well as MRI with DTI. We carried out cross-subject comparisons using tract-based spatial statistics. As expected, reaction time slowed significantly with age. In diffuse areas of frontal and parietal white matter, especially the anterior corpus callosum, fractional anisotropy values correlated negatively with reaction time. The genu and body of the corpus callosum, superior longitudinal fasciculus, and inferior fronto-occipital fasciculus were among the areas most involved. This relationship was not explained by gray or white matter atrophy or by white matter lesion volume. In a statistical mediation analysis, loss of white matter integrity mediated the relationship between age and cognitive processing speed.
AB - Cognitive processing slows with age. We sought to determine the importance of white matter integrity, assessed by diffusion tensor imaging (DTI), at influencing cognitive processing speed among normal older adults, assessed using a novel battery of computerized, non-verbal, choice reaction time tasks. We studied 131 cognitively normal adults aged 55-87 using a cross-sectional design. Each participant underwent our test battery, as well as MRI with DTI. We carried out cross-subject comparisons using tract-based spatial statistics. As expected, reaction time slowed significantly with age. In diffuse areas of frontal and parietal white matter, especially the anterior corpus callosum, fractional anisotropy values correlated negatively with reaction time. The genu and body of the corpus callosum, superior longitudinal fasciculus, and inferior fronto-occipital fasciculus were among the areas most involved. This relationship was not explained by gray or white matter atrophy or by white matter lesion volume. In a statistical mediation analysis, loss of white matter integrity mediated the relationship between age and cognitive processing speed.
UR - https://www.scopus.com/pages/publications/84869858812
U2 - 10.1371/journal.pone.0050425
DO - 10.1371/journal.pone.0050425
M3 - Article
C2 - 23185621
AN - SCOPUS:84869858812
SN - 1932-6203
VL - 7
JO - PloS one
JF - PloS one
IS - 11
M1 - e50425
ER -