title: The effect of aging on fronto-striatal reactive and proactive inhibitory control.
abstract: Inhibitory control, like most cognitive processes, is subject to an age-related decline. The effect of age on neurofunctional inhibition processing remains uncertain, with age-related increases as well as decreases in activation being reported. This is possibly because reactive (i.e., outright stopping) and proactive inhibition (i.e., anticipation of stopping) have not been evaluated separately. Here, we investigate the effects of aging on reactive as well as proactive inhibition, using functional MRI in 73 healthy subjects aged 30-70years. We found reactive inhibition to slow down with advancing age, which was paralleled by increased activation in the motor cortex. Behaviorally, older adults did not exercise increased proactive inhibition strategies compared to younger adults. However, the pattern of activation in the right inferior frontal gyrus (rIFG) showed a clear age-effect on proactive inhibition: rather than flexibly engaging the rIFG in response to varying stop-signal probabilities, older subjects showed an overall hyperactivation. Whole-brain analyses revealed similar hyperactivations in various other frontal and parietal brain regions. These results are in line with the neural compensation hypothesis of aging: processing becomes less flexible and efficient with advancing age, which is compensated for by overall enhanced activation. Moreover, by disentangling reactive and proactive inhibition, we can show for the first time that the age-related increase in activation during inhibition that is reported generally by prior studies may be the result of compensation for reduced neural flexibility related to proactive control strategies.
authors.affiliation: Brain Center Rudolf Magnus, Department of Psychiatry, University Medical Center Utrecht, Utrecht,The Netherlands.
authors.forename: Iris
authors.initials: I
authors.lastname: Kleerekooper
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine,Atlanta, GA, USA.
authors.forename: Sanne J H
authors.initials: SJH
authors.lastname: van Rooij
authors.affiliation: Amsterdam Brain and Cognition, Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Wery P M
authors.initials: WPM
authors.lastname: van den Wildenberg
authors.affiliation: Brain Center Rudolf Magnus, Department of Psychiatry, University Medical Center Utrecht, Utrecht,The Netherlands.
authors.forename: Max
authors.initials: M
authors.lastname: de Leeuw
authors.affiliation: Brain Center Rudolf Magnus, Department of Psychiatry, University Medical Center Utrecht, Utrecht,The Netherlands.
authors.forename: Rene S
authors.initials: RS
authors.lastname: Kahn
authors.affiliation: Brain Center Rudolf Magnus, Department of Psychiatry, University Medical Center Utrecht, Utrecht,The Netherlands; Departments of Experimental and Developmental Psychology, Faculty of Social Sciences, Utrecht University, Utrecht, The Netherlands. Electronic address: m.vink2@uu.nl.
authors.forename: Matthijs
authors.initials: M
authors.lastname: Vink
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D001931:Brain Mapping; D003342:Corpus Striatum / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011930:Reaction Time