999
Views
53
CrossRef citations to date
0
Altmetric
Original Articles

Grammatical impairments in PPA

&
Pages 1018-1037 | Published online: 09 May 2014
 

Abstract

Background: Grammatical impairments are commonly observed in the agrammatic subtype of primary progressive aphasia (PPA-G), whereas grammatical processing is relatively preserved in logopenic (PPA-L) and semantic (PPA-S) subtypes.

Aims: We review research on grammatical deficits in PPA and associated neural mechanisms, with discussion focused on production and comprehension of four aspects of morphosyntactic structure: grammatical morphology, functional categories, verbs and verb argument structure, and complex syntactic structures. We also address assessment of grammatical deficits in PPA, with emphasis on behavioural tests of grammatical processing. Finally, we address research examining the effects of treatment for progressive grammatical impairments.

Main Contribution: PPA-G is associated with grammatical deficits that are evident across linguistic domains in both production and comprehension. PPA-G is associated with damage to regions including the left inferior frontal gyrus and dorsal white matter tracts, which have been linked to impaired comprehension and production of complex sentences. Detailing grammatical deficits in PPA is important for estimating the trajectory of language decline and associated neuropathology. We, therefore, highlight several new assessment tools for examining different aspects of morphosyntactic processing in PPA.

Conclusions: Individuals with PPA-G present with agrammatic deficit patterns distinct from those associated with PPA-L and PPA-S, but similar to those seen in agrammatism resulting from stroke, and patterns of cortical atrophy and white matter changes associated with PPA-G have been identified. Methods for clinical evaluation of agrammatism, focusing on comprehension and production of grammatical morphology, functional categories, verbs and verb argument structure, and complex syntactic structures are recommended and tools for this are emerging in the literature. Further research is needed to investigate the real-time processes underlying grammatical impairments in PPA, as well as the structural and functional neural correlates of grammatical impairments across linguistic domains. Few studies have examined the effects of treatment for grammatical impairments in PPA; research in this area is needed to better understand how (or if) grammatical processing ability can be improved, the potential for spared neural tissue to be recruited to support this and whether the neural connections within areas of dysfunctional tissue required for grammatical processing can be enhanced using cortical stimulation.

This work was support by the National Institutes of Health [grant numbers R01DC01948-20 and R01DC008552]. The authors also wish to acknowledge M. Marsel Mesulam, Sandra Weintraub, and Christina Wieneke for their substantial contributions to the work discussed herein.

Log in via your institution

Log in to Taylor & Francis Online

PDF download + Online access

  • 48 hours access to article PDF & online version
  • Article PDF can be downloaded
  • Article PDF can be printed
USD 53.00 Add to cart

Issue Purchase

  • 30 days online access to complete issue
  • Article PDFs can be downloaded
  • Article PDFs can be printed
USD 386.00 Add to cart

* Local tax will be added as applicable

Related Research

People also read lists articles that other readers of this article have read.

Recommended articles lists articles that we recommend and is powered by our AI driven recommendation engine.

Cited by lists all citing articles based on Crossref citations.
Articles with the Crossref icon will open in a new tab.