Neural Resources Supporting Language Production vs. Comprehension in Chronic Post-stroke Aphasia: A Meta-Analysis Using Activation Likelihood Estimates.

Arianna N. LaCroix,Corianne Rogalsky,Eltonnelle James

doi:10.3389/fnhum.2021.680933

Arianna N. LaCroix, Corianne Rogalsky + Show 1 more

Open Access

https://doi.org/10.3389/fnhum.2021.680933

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Abstract

In post-stroke aphasia, language tasks recruit a combination of residual regions within the canonical language network, as well as regions outside of it in the left and right hemispheres. However, there is a lack of consensus as to how the neural resources engaged by language production and comprehension following a left hemisphere stroke differ from one another and from controls. The present meta-analysis used activation likelihood estimates to aggregate across 44 published fMRI and PET studies to characterize the functional reorganization patterns for expressive and receptive language processes in persons with chronic post-stroke aphasia (PWA). Our results in part replicate previous meta-analyses: we find that PWA activate residual regions within the left lateralized language network, regardless of task. Our results extend this work to show differential recruitment of the left and right hemispheres during language production and comprehension in PWA. First, we find that PWA engage left perilesional regions during language comprehension, and that the extent of this activation is likely driven by stimulus type and domain-general cognitive resources needed for task completion. In contrast to comprehension, language production was associated with activation of the right frontal and temporal cortices. Further analyses linked right hemisphere regions involved in motor speech planning for language production with successful naming in PWA, while unsuccessful naming was associated with the engagement of the right inferior frontal gyrus, a region often implicated in domain-general cognitive processes. While the within-group findings indicate that the engagement of the right hemisphere during language tasks in post-stroke aphasia differs for expressive vs. receptive tasks, the overall lack of major between-group differences between PWA and controls implies that PWA rely on similar cognitive-linguistic resources for language as controls. However, more studies are needed that report coordinates for PWA and controls completing the same tasks in order for future meta-analyses to characterize how aphasia affects the neural resources engaged during language, particularly for specific tasks and as a function of behavioral performance.

Highlights

Aphasia is an acquired communication disorder in which individuals have difficulty with the production and/or comprehension of language, typically following a left hemisphere stroke
We first computed an Activation likelihood estimation (ALE) which combined language production and comprehension in a single analysis to identify neural resources which are generally engaged by language in persons with aphasia (PWA) and controls, regardless of task
We further sought to characterize how the neural resources engaged by language production and comprehension in PWA compares to what is observed in control subjects, as well as how the neural resources may differ based on task type

Summary

Introduction

Aphasia is an acquired communication disorder in which individuals have difficulty with the production and/or comprehension of language, typically following a left hemisphere stroke. Focal damage can lead to widespread disruptions of functionally and/or anatomically connected brain regions that support language; for example by disrupting critical white matter tracts (Price et al, 2001; Martin et al, 2009; Barwood et al, 2011; Papoutsi et al, 2011; Basilakos et al, 2014; Forkel et al, 2014; Xing et al, 2017, 2018) Both lesion size and location have been associated with behavioral outcomes including overall aphasia severity and specific language abilities (e.g., auditory comprehension, verbal expression; Plowman et al, 2012; Forkel et al, 2014; Marebwa et al, 2017; Xing et al, 2017, 2018; Thye and Mirman, 2018; Benghanem et al, 2019; Turkeltaub, 2019; Wilson and Schneck, 2021). The exact neural resources engaged during language tasks in persons with aphasia (PWA) is known to be influenced by task demands, and dependent upon the location of the lesion that resulted in language impairments (Blank et al, 2003; Cherney and Small, 2006; Sebastian and Kiran, 2011; Skipper-Kallal et al, 2017)

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