Corpus callosum size, reaction time speed and variability in mild cognitive disorders and in a normative sample

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Kaarin J. Anstey - , Australian National University (Autor:in)
  • Holly A. Mack - , Australian National University (Autor:in)
  • Helen Christensen - , Australian National University (Autor:in)
  • Shu Chen Li - , Max Planck Institute for Human Development (Autor:in)
  • Chantal Reglade-Meslin - , Australian National University (Autor:in)
  • Jerome Maller - , Alfred Health (Autor:in)
  • Rajeev Kumar - , Australian National University (Autor:in)
  • Keith Dear - , Australian National University (Autor:in)
  • Simon Easteal - , Australian National University (Autor:in)
  • Perminder Sachdev - , University of New South Wales (Autor:in)

Abstract

Intra-individual variability in reaction time increases with age and with neurological disorders, but the neural correlates of this increased variability remain uncertain. We hypothesized that both faster mean reaction time (RT) and less intra-individual RT variability would be associated with larger corpus callosum (CC) size in older adults, and that these associations would be stronger in adults with mild cognitive disorders. A normative sample (n = 432) and a sample with mild cognitive disorders (n = 57) were compared on CC area, RT mean and RT variability adjusting for age, sex, education, APOE genotype, smoking, alcohol consumption, grip strength, visual acuity, handedness and lung function. Samples did not differ in CC area or intra-cranial volume. In the normative sample, simple RT (SRT) and choice RT (CRT) were negatively associated with CC area but there were minimal associations between CC area and intra-individual RT variability. In the mild cognitive disorders sample, SRT, CRT and intra-individual variability on the SRT task were associated with CC area. Increased RT variability explained up to 12.7 percent of the variance in CC area in the sample with mild cognitive disorders, but less than 1 percent of the variance in CC area in the normative sample. There were no associations with APOE genotype. We conclude that intra-individual variability is associated with CC area in mild cognitive disorders, but not in normal aging. We propose that biological limits on reserve capacity must occur in mild cognitive disorders that result in stronger brain-behavior relationships being observed.

Details

OriginalspracheEnglisch
Seiten (von - bis)1911-1920
Seitenumfang10
FachzeitschriftNeuropsychologia
Jahrgang45
Ausgabenummer8
PublikationsstatusVeröffentlicht - 2007
Peer-Review-StatusJa
Extern publiziertJa

Externe IDs

PubMed 17240409
ORCID /0000-0001-8409-5390/work/142254950

Schlagworte

Schlagwörter

  • APOE, Cognitive aging, Mild cognitive impairment, Processing speed, RT variability, Sex differences

Bibliotheksschlagworte