Verb-argument integration in primary progressive aphasia: Real-time argument access and selection. (November 2019)

• Record Type: Journal Article
• Authors: Mack, Jennifer E.; Mesulam, M.-Marsel; Rogalski, Emily J.; Thompson, Cynthia K.
• Is Part Of: Neuropsychologia. Volume 134(2019)
• Publication Date: 2019-11
• Subjects: Primary progressive aphasia -- Eye-tracking -- Syntax -- Semantics -- Verb-argument structure; Neuropsychology -- Periodicals; Neurology -- Periodicals; Psychophysiology -- Periodicals; Neuropsychologie -- Périodiques; Neuropsychology; Periodicals; Electronic journals; 616.8
• DOI: 10.1016/j.neuropsychologia.2019.107192
• Languages: English
• ISSNs: 0028-3932

Abstract

Abstract: Background: Impaired sentence comprehension is observed in the three major subtypes of PPA, with distinct performance patterns relating to impairments in comprehending complex sentences in the agrammatic (PPA-G) and logopenic (PPA-L) variants and word comprehension in the semantic subtype (PPA-S). However, little is known about basic combinatory processes during sentence comprehension in PPA, such the integration of verbs with their subject and object(s) ( verb-argument integration ). Methods: The present study used visual-world eye-tracking to examine real-time verb-argument integration in individuals with PPA (12 with PPA-G, 10 with PPA-L, and 6 with PPA-S) and neurotypical older adults (15). Two baseline experiments probed eye movement control, using a non-linguistic task, and noun comprehension, respectively. Two verb-argument integration experiments examined the effects of verb meaning on (a) lexical access of the verb's direct object ( argument access ) and (b) selection of a semantically-appropriate direct object ( argument selection ), respectively. Eye movement analyses were conducted only for trials with correct behavioral responses, allowing us to distinguish accuracy and online processing. Results: The eye movement control experiment revealed no significant impairments in PPA, whereas the noun comprehension experiment revealed reduced accuracy and eye-movement latencies in PPA-S, and to a lesser extent PPA-G. In the argument access experiment, verb meaning facilitated argument access normally in PPA-G and PPA-L; in PPA-S, verb-meaning effects emerged on an atypical time course. In the argument selection experiment, significant impairments in accuracy were observed only in PPA-G, accompanied by markedly atypical eye movement patterns. Conclusion: This study revealed two distinct patterns of impaired verb-argument integration in PPA. In PPA-S, impaired verb-argument integration was observed in the argument access experiment, indicating impairments in basic semantic combinatory processes which likely relate to damage in ventral language pathways. In contrast, listeners with PPA-G showed marked impairments of argument selection, likely relating to damage to left inferior frontal regions. Highlights: The study examined verb-argument integration in primary progressive aphasia (PPA). Eye-tracking (ET) was used to measure language processing and oculomotor control. ET data revealed impaired language processing but intact oculomotor control in PPA. Semantic PPA (PPA-S) was associated with impaired verb-argument access. Agrammatic PPA (PPA-G) was associated with impaired verb-argument selection.