In older adults, maintaining balance and processing information typically interfere with each other, suggesting that executive functions may be engaged for both. We investigated associations between measures of inhibitory processes and standing postural control in healthy young and older adults. Perceptual and motor inhibition was measured using a protocol adapted from Nassauer and Halperin (2003, Dissociation of perceptual and motor inhibition processes through the use of novel computerized conflict tasks. Journal of the International Neuropsychological Society, 9, 25-30). These measures were then correlated to postural sway during standing conditions that required resolving various levels of sensory conflict, for example, world-fixed versus sway-referenced floor and visual scene. In the older adults, perceptual inhibition was positively correlated with sway amplitude on a sway-referenced floor and with a fixed visual scene (r = .68, p < .001). Motor inhibition was not correlated with sway on either group. Perceptual inhibition may be a component of the sensory integration process important for maintaining balance in older adults.

ObjectiveTo determine whether reduction in brain grey matter volume associated with hypertension persisted or was remediated among hypertensive patients newly treated over the course of a year.MethodsForty-one hypertensive patients were assessed over the course of a one-year successful anti-hypertensive treatment. Brain areas identified previously in cross-sectional studies as differing in volume between hypertensive and normotensive individuals were examined with a semi-automated measurement technique (ALP, automated labeling pathway). Volumes of grey matter regions were computed at baseline and after a year of treatment and compared to archival data from normotensive individuals.ResultsReductions in regional grey matter volume over the follow-up period were observed despite successful treatment of blood pressure. The comparison group of older, but normotensive individuals showed no significant changes over a year in the regions tested in the treated hypertensive group.ConclusionsThese novel results suggest that essential hypertension is associated with regional grey matter shrinkage and successful reduction of blood pressure may not completely counter that trend.

We asked whether different forms of inhibition are altered differently by aging using a Motor and Perceptual Inhibition Test (MAPIT) based on Nassauer and Halperin (Nassauer & Halperin, 2003). Ninety-eight individuals participating in studies of balance and attention were separated into younger (mean age 25 years) and older participants (mean age 73). Older participants showed less Perceptual and Motor Inhibition than younger participant with moderation of this effect by gender. The two scores were uncorrelated in the young but significantly correlated in the older group. Overall, the MAPIT appeared to yield reliable measures of two aspects of inhibition that demonstrate a differential impact of age. KeywordsReaction time; executive function; reliability; human performance; processing speed; response choice Lessened inhibition has been theoretically linked to aging, at least since the influential chapter of Hasher and Zacks (L. Hasher & Zacks, 1988). The theory is controversial, however, and has recently been updated (Lustig, Hasher, & Zacks, 2007). Most importantly from the current perspective, Lustig et al. (Lustig et al., 2007) review three types of inhibition influenced by aging: a) controlling access to attention's focus, b) deleting irrelevant information from attention and working memory, and c) suppressing or restraining strong but inappropriate responses. Their review highlights aging influences on all three of their forms of inhibition and discusses the yet unresolved issue of the relationship among these forms of inhibition. Their review of both behavioral and brain imaging results suggests that these forms of inhibition overlap, sharing a core process or set of processes. Each, however, has distinctive features that may vary for specific tasks and due to individual differences. An analogy might be drawn to intelligence that is commonly thought to have verbal and performance aspects that are correlated, but also have distinctive features and predictivity to other variables.The inhibitory deficit view is not without its critics (Burke & Osborne, 2007;McDowd, 1997). These critics point out difficulties showing inhibitory deficits in particular tasks, e.g., negative priming tasks, and also note the importance of disentangling basic sensory and response speed deficits from presumed inhibitory deficits. The latter concern has been addressed to some extent. In a well examined sample, Christ and colleagues (Christ et al., 2001;McAuley et al., 2006) addressed this concern and established that the inhibitory deficit in the older participants could not be explained by response slowing. They went on to Contact: J. Richard Jennings, JenningsJR@upmc.edu, phone 1-412-246-6220, fax 1-412-246 6210.. show with ex-Gaussian analysis that inhibitory limitations in older adults differed in quality from those in children. NIH Public AccessConsiderably more attention has been paid to whether inhibition is a unitary construct and whether aging is characterized by a decline in all forms of inhibition or only a decline...

Inhibitory processes have been suggested to be involved in maintaining balance in older adults, specifically in the integration of sensory information. This study investigated the association between inhibition and the ability to shift attention between auditory and visual modalities during a balance challenge. Young (21–35 yrs; n=24) and older (70–85 yrs; n=22) healthy subjects completed tasks assessing perceptual inhibition and motor inhibition. Subjects then performed dual-task paradigms pairing auditory and visual choice reaction time tasks with different postural conditions. Sensory channel switch cost was quantified as the difference between visual and auditory reaction times. Results showed that better perceptual and motor inhibition capabilities were associated with less sensory switch cost in the old (perceptual inhibition: r=0.51; motor inhibition: r=0.48). In the young, neither perceptual nor motor inhibition was associated with sensory switch cost. Inhibitory skills appear particularly important in the elderly for processing events from multiple sensory channels while maintaining balance.

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