Thematic Integration Impairments in Primary Progressive Aphasia: Evidence From Eye-Tracking

Abstract

Primary progressive aphasia (PPA) is a degenerative disease affecting language while leaving other cognitive facilities relatively unscathed. The agrammatic subtype of PPA (PPA-G) is characterized by agrammatic language production with impaired comprehension of noncanonical filler-gap syntactic structures, such as object-relatives [e.g., The sandwich that the girl ate (gap) was tasty], in which the filler (the sandwich) is displaced from the object position within the relative clause to a position preceding both the verb and the agent (the girl) and is replaced by a gap linked with the filler. One hypothesis suggests that the observed deficits of these structures reflect impaired thematic integration, including impaired prediction of the thematic role of the filler and impaired thematic integration at the gap, but spared structure building (i.e., creation of the gap). In the current study, we examined the on-line comprehension of object-relative and subject-relative clauses in healthy controls and individuals with agrammatic and logopenic PPA using eye-tracking. Eye-movement patterns in canonical subject-relative clause structures were essentially spared in both PPA groups. In contrast, eye-movement patterns in noncanonical object-relative clauses revealed delayed thematic prediction in both agrammatic and logopenic PPA, on-time structure building (i.e., gap-filling) in both groups, and abnormal thematic integration in agrammatic, but not logopenic, PPA. We argue that these results are consistent with the hypothesis that agrammatic comprehension deficits reflect impaired thematic integration.

Dissociating nouns and verbs in temporal and perisylvian networks: Evidence from neurodegenerative diseases

“…Recent on-line sentence comprehension studies demonstrated abnormal thematic integration in nfvPPA, but not lvPPA using eye-tracking (Walenski, Mack, Mesulam, & Thompson, 2020), and abnormal ERP (reduced p600) to verb-argument structure violations in both subtypes, with nfvPPA also showing no evidence of morphosyntactic violation detection (Barbieri et al, 2021). Indeed, the strong association between sentence-processing impairments (as measured by sentence production on the NAT which included written labels for the agent, verb, and patient) and verb performance supported hypotheses of the neural separation of integration processes (e.g., thematic integration), engaging primarily left IFG/MFG and pSTS (in line with Bornkessel-Schlesewsky & Schlesewsky, 2013;Lukic et al, 2021;Shapiro, Moo, & Caramazza, 2006).…”

Nonspecific Effects of Normal Aging on Taxonomic and Thematic Semantic Processing

“…These sample sizes were established in view of the protocols applied in many other studies Kalénine, Mirman, Middleton, et al, 2012;Lee et al, 2014 ;Merck et al, 2020;Mirman et al, 2011;Mirman & Graziano, 2012a;Walenski et al, 2020) using both equivalent paradigm and statistical approach (see below for description).…”

“…Combined with a statistical approach allowing changes in gaze behavior to be analyzed over time, it has been successfully used to compare the amplitude and time course of taxonomic and thematic processing Kalénine, Mirman, Middleton, et al, 2012;Merck et al, 2020;Mirman & Graziano, 2012a;Mirman & Graziano, 2012b;Mirman & Magnuson, 2009). As time courses of gaze data involve multiple data point, the method is powerful, and allows to demonstrated differences in taxonomic and thematic processing even in small samples of participants (from 6-8 for patient groups to 15-20 for healthy participants, see Mirman et al, 2011; for equivalent sample sizes see also Kalénine, Mirman, Middleton, et al, 2012;Lee et al, 2014 ;Merck et al, 2020;Mirman & Graziano, 2012a;Walenski et al, 2020). Moreover, it can highlight both reduced/delayed (reflecting impaired semantic activation) and increased/earlier (reflecting exaggerated semantic activation) semantic competition .…”