Executive performance is related to regional gray matter volume in healthy older individuals

Authors

  • Ruth Ruscheweyh,

    Corresponding author
    1. Department of Neurology, University Hospital of Münster, Münster, Germany
    2. Department of Neurology, University of München, München, Germany
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    • R. Ruscheweyh and M. Deppe contributed equally to this work.

  • Michael Deppe,

    1. Department of Neurology, University Hospital of Münster, Münster, Germany
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    • R. Ruscheweyh and M. Deppe contributed equally to this work.

  • Hubertus Lohmann,

    1. Department of Neurology, University Hospital of Münster, Münster, Germany
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  • Heike Wersching,

    1. Department of Neurology, University Hospital of Münster, Münster, Germany
    2. German Atrial Fibrillation Competence NETwork (AFNET), University of Münster, Münster, Germany
    3. Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany
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  • Catharina Korsukewitz,

    1. Department of Neurology, University Hospital of Münster, Münster, Germany
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  • Thomas Duning,

    1. Department of Neurology, University Hospital of Münster, Münster, Germany
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  • Saskia Bluhm,

    1. Department of Neurology, University Hospital of Münster, Münster, Germany
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  • Christoph Stehling,

    1. German Atrial Fibrillation Competence NETwork (AFNET), University of Münster, Münster, Germany
    2. Department of Clinical Radiology, University of Münster, Münster, Germany
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  • Simon S. Keller,

    1. Department of Neurology, University Hospital of Münster, Münster, Germany
    2. Department of Clinical Neuroscience, Institute of Psychiatry, King's College, London, UK
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  • Stefan Knecht

    1. Department of Neurology, University Hospital of Münster, Münster, Germany
    2. German Atrial Fibrillation Competence NETwork (AFNET), University of Münster, Münster, Germany
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Abstract

Individual differences in executive functioning and brain morphology are considerable. In this study, we investigated their interrelation in a large sample of healthy older individuals. Digit span, trail-making, and Stroop tasks were used to assess different executive subfunctions in 367 nondemented community-dwelling individuals (50–81 years). Task performance was analyzed relative to brain structure using voxel-based morphometry, corrected for age and sex. Improved task performance was associated with increased local gray matter volume in task-specific patterns that showed partial, but not complete overlap with known task-specific functional imaging patterns. While all three tasks showed associations with prefrontal gray matter volume as expected for executive functioning, the strongest overlap between the three tasks was found in insular cortex, suggesting that it has a previously underestimated role for executive functions. The association between the insular cortex and executive functioning was corroborated using stereological region-of-interest measurement of insular volume in a subgroup of 93 subjects. Quantitatively, the volume of the single most strongly related region explained 2.4 ± 1.1% of the variance in executive performance over and above the variance explained by age, which amounted to 7.4 ± 4.1%. The age-independent peak associations between executive performance and gray matter described here occurred in regions that were also strongly affected by age-related gray matter atrophy, consistent with the hypothesis that age-related regional brain volume loss and age-related cognitive changes are linked. Hum Brain Mapp 34:3333–3346, 2013. © 2012 Wiley Periodicals, Inc.

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