An adaptive semantic matching paradigm for reliable and valid language mapping in individuals with aphasia

Abstract

Research on neuroplasticity in recovery from aphasia depends on the ability to identify language areas of the brain in individuals with aphasia. However, tasks commonly used to engage language processing in people with aphasia, such as narrative comprehension and picture naming, are limited in terms of reliability (test-retest reproducibility) and validity (identification of language regions, and not other regions). On the other hand, paradigms such as semantic decision that are effective in identifying language regions in people without aphasia can be prohibitively challenging for people with aphasia. This paper describes a new semantic matching paradigm that uses an adaptive staircase procedure to present individuals with stimuli that are challenging yet within their competence, so that language processing can be fully engaged in people with and without language impairments. The feasibility, reliability and validity of the adaptive semantic matching paradigm were investigated in sixteen individuals with chronic post-stroke aphasia and fourteen neurologically normal participants, in comparison to narrative comprehension and picture naming paradigms. All participants succeeded in learning and performing the semantic paradigm. Test-retest reproducibility of the semantic paradigm in people with aphasia was good (Dice coefficient = 0.66), and was superior to the other two paradigms. The semantic paradigm revealed known features of typical language organization (lateralization; frontal and temporal regions) more consistently in neurologically normal individuals than the other two paradigms, constituting evidence for validity. In sum, the adaptive semantic matching paradigm is a feasible, reliable and valid method for mapping language regions in people with aphasia.

The Cortical Organization of Syntax

“…In contrast to the weak and variable effects in the pIFG, damage to the pMTG is robustly associated with basic sentence comprehension deficits across many studies (Dronkers et al, 2004;Amici et al, 2007;Baldo and Dronkers, 2007;Race et al, 2012;Magnusdottir et al, 2013;Pillay et al, 2017;Fridriksson et al, 2018;Rogalsky et al, 2018;Wilson et al, 2018b;Wilson et a., 2018c). Importantly, such deficits cannot be simply attributed to word-level deficits as single word comprehension impairments are rare and typically mild following left unilateral injury (Rogalsky et al, 2008b), even when encompassing posterior temporal cortex (Selnes et al, 1984;Wilson et al, 2018b;Wilson et al 2018c). In contrast, sentence comprehension deficits are more readily detected, even for simple experimental tasks (Dronkers et al, 2004;Wilson et al, 2018b;Wilson et al 2018c) that do not place high demands on working memory or executive function resources.…”

“…Importantly, such deficits cannot be simply attributed to word-level deficits as single word comprehension impairments are rare and typically mild following left unilateral injury (Rogalsky et al, 2008b), even when encompassing posterior temporal cortex (Selnes et al, 1984;Wilson et al, 2018b;Wilson et al 2018c). In contrast, sentence comprehension deficits are more readily detected, even for simple experimental tasks (Dronkers et al, 2004;Wilson et al, 2018b;Wilson et al 2018c) that do not place high demands on working memory or executive function resources.…”

“…Yagata et al, (2017) report two cases studies of paragrammatic patients, both with confirmed damage to the posterior temporal and inferior parietal lobes and no frontal lobe damage. In addition, Wilson et al present several case studies in which paragrammatism and sentence comprehension deficits were associated with posterior temporal damage (see patients included in both Wilson et al, 2018b andWilson et al, 2018c).…”

“…In the 1970s it was discovered that Broca's aphasia is also associated with particular sentence comprehension deficits that suggested a fundamental syntactic problem (Caramazza & Zurif, 1976), kicking off decades of intense investigation of the role of Broca's area in syntactic processing, assessed primarily via comprehension tasks (Grodizinsky & Amunts, 2006;Matchin & Rogalsky, 2017). However, while some large-scale lesion-deficit mapping studies have reported an association between damage to Broca's area and comprehension of syntactically complex and/or non-canonical sentence structures (Wilson et al, 2011;Magnusdottir et al, 2013;Mesulam et al, 2015;Fridriksson et al, 2018), many others have primarily implicated the posterior temporal lobe in basic syntactic processing and not Broca's area (Dronkers et al, 2004;Wilson & Saygin, 2004;Baldo & Dronkers, 2007;Peelle et al, 2008;Pillay et al, 2017;Rogalsky, et al 2018;Wilson et al, 2018b;2018c).…”

A systematic review of neuroimaging approaches to mapping language in individuals

“…• Lateralization Index (LI) is used as a comparative measure of language related activations between the hemispheres of the brain. Although not a reliability measure on its own, a considerable number of papers rely on the reproducibility of LI as a reliability metric (Agarwal et al 2018;Benjamin et al 2017;Fernandez et al 2003;Knecht et al 2003;Nettekoven et al 2018;Otzenberger et al 2005;Voyvodic 2012;Wilson et al 2018). A score of 1 indicates fully left lateralized activation, a score of -1 indicates fully right lateralized activation, and a score of 0 refers to bilateral (i.e.…”