An Activation Likelihood Estimation Meta-Analysis Study of Simple Motor Movements in Older and Young Adults.

Ted K Turesky,Peter E Turkeltaub,Guinevere F Eden

doi:10.3389/fnagi.2016.00238

Abstract

The functional neuroanatomy of finger movements has been characterized with neuroimaging in young adults. However, less is known about the aging motor system. Several studies have contrasted movement-related activity in older versus young adults, but there is inconsistency among their findings. To address this, we conducted an activation likelihood estimation (ALE) meta-analysis on within-group data from older adults and young adults performing regularly paced right-hand finger movement tasks in response to external stimuli. We hypothesized that older adults would show a greater likelihood of activation in right cortical motor areas (i.e., ipsilateral to the side of movement) compared to young adults. ALE maps were examined for conjunction and between-group differences. Older adults showed overlapping likelihoods of activation with young adults in left primary sensorimotor cortex (SM1), bilateral supplementary motor area, bilateral insula, left thalamus, and right anterior cerebellum. Their ALE map differed from that of the young adults in right SM1 (extending into dorsal premotor cortex), right supramarginal gyrus, medial premotor cortex, and right posterior cerebellum. The finding that older adults uniquely use ipsilateral regions for right-hand finger movements and show age-dependent modulations in regions recruited by both age groups provides a foundation by which to understand age-related motor decline and motor disorders.

Highlights

Voluntary finger-movement tasks are commonly employed in neuroimaging studies
We differentiated the subdivisions of medial premotor cortex (MPMC) and LPMC, but not SM1, because most of the studies used in this meta-analysis showed activation in M1 and S1, and those activations registered in a single cluster
Young Adults For right-hand finger movement in young adults, we observed significant likelihoods of activation in left SM1 extending into PMd%1, bilateral pre-SMA, left SMA, right SMA, left inferior parietal lobule (IPL), bilateral insula, left putamen, left thalamus, and bilateral anterior cerebellum (Figure 1A)

Summary

Introduction

Voluntary finger-movement tasks are commonly employed in neuroimaging studies. far, the brain bases of this type of motor function have been well-characterized in young adults (Chouinard and Paus, 2006; Witt et al, 2008). A subset of studies used right-hand index finger-tapping tasks and were analyzed separately (Witt et al, 2008) This specific ALE map revealed likelihoods of activation in left primary sensorimotor cortex (SM1), supplementary motor area. Motor Movements in Older Adults (SMA), ventral premotor cortex (PMv), basal ganglia, as well as bilateral anterior cerebellum, claustra, dorsal premotor cortex (PMd), and dorsolateral prefrontal cortex (DLPFC) and right inferior parietal lobule (IPL), insula, and inferior frontal gyrus (IFG). These brain regions do not function in isolation, but are part of extensive efferent and afferent motor control pathways. Afferent pathways originating at receptors in the skin, joints, and muscles feed back (e.g., about whether the target has been reached) to somatosensory cortex and cerebellum, which eventually project to cortical motor areas to improve subsequent movements

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