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

Kaarin J. Anstey; Holly A. Mack; Helen Christensen; Shu-Chen Li; Chantal Reglade-Meslin; Jerome Maller; Rajeev Kumar; Keith Dear; Simon Easteal; Perminder Sachdev

doi:10.1016/j.neuropsychologia.2006.11.020

Back

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

Journal article

Peer reviewed

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

Kaarin J. Anstey, Holly A. Mack, Helen Christensen, Shu-Chen Li, Chantal Reglade-Meslin, Jerome Maller, Rajeev Kumar, Keith Dear, Simon Easteal and Perminder Sachdev

Neuropsychologia, Vol.45(8), pp.1911-1920

01/01/2007

DOI: 10.1016/j.neuropsychologia.2006.11.020

PMID: 17240409

View Online

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.

APOE

Cognitive aging

Mild cognitive impairment

Processing speed

RT variability

Sex differences

Details

Title: Subtitle: Corpus callosum size, reaction time speed and variability in mild cognitive disorders and in a normative sample
Creators: Kaarin J. Anstey - Australian National University
Holly A. Mack - Australian National University
Helen Christensen - Australian National University
Shu-Chen Li - Max Planck Institute for Human Development
Chantal Reglade-Meslin - Australian National University
Jerome Maller - The Alfred Hospital
Rajeev Kumar - Australian National University
Keith Dear - Australian National University
Simon Easteal - Australian National University
Perminder Sachdev - UNSW Sydney
Resource Type: Journal article
Publication Details: Neuropsychologia, Vol.45(8), pp.1911-1920
DOI: 10.1016/j.neuropsychologia.2006.11.020
PMID: 17240409
NLM abbreviation: Neuropsychologia
ISSN: 0028-3932
eISSN: 1873-3514
Publisher: Elsevier Ltd
Number of pages: 10
Language: English
Date published: 01/01/2007
Academic Unit: Radiology
Record Identifier: 9984848509302771

Metrics

2 Record Views