Assessing syntactic deficits in Chinese Broca’s aphasia using theNorthwestern Assessment of Verbs and Sentences-Chinese (NAVS-C)

Abstract

Background English-speaking patients with Broca's aphasia and agrammatism evince difficulty with complex grammatical structures, including verbs and sentences. A few studies have found similar patterns among Chinese-speaking patients with broca's aphasia, despite structural differences between these two languages. However, no studies have explicitly examined verb properties, including the number and optionality of arguments (participant roles) selected by the verb, and only a few studies have examined sentence deficits among Chinese patients. In addition, there are no test batteries presently available to assess syntactically important properties of verbs and sentences in Chinese patients. Aims This study used a Chinese version of the Northwestern Assessment of Verbs and Sentences (NAVS; Thompson, 2011), originally developed for English speakers with aphasia, to examine the verb and sentence deficit patterns among Chinese speakers with aphasia. As in the original NAVS, the Chinese version (NAVS-C) assessed verbs by the number and optionality of arguments as well as sentence canonicity, in the both production and comprehension. Methods and Procedures Fifteen Chinese patients with Broca's aphasia and fifteen age-matched healthy normal controls participated in this study. All NAVS-C tests were administered, in which participants were asked either to produce or identify verbs and sentences coinciding with action pictures. Outcomes & results Despite grammatical differences between Chinese and English, the impairment caused by structural complexity of verbs and sentences was replicated in Chinese-speaking patients using the NAVS-C. Verbs with more arguments were significantly more impaired than those with fewer arguments and verbs with optional arguments were significantly more impaired than those with obligatory arguments. One deviation from English-speaking patients, however, is that the Chinese-speaking patients exhibited greater difficulty with subject relative clauses than with object relative clauses because the former, rather than the latter, involve non-canonical order in Chinese. Similar to English-speaking patients, Chinese patients exhibited more difficulty with object extracted wh-questions than with subject extracted wh-questions. Suggesting that wh-movement in Logical Form may also cause processing difficulty. Moreover, Chinese-speaking patients exhibited similar performance in both production and comprehension, indicating the deficits in both modalities. Conclusions The number and optionality of verb arguments as well as canonicity of the Agent-Theme order in sentences impacts Chinese-speaking individuals with aphasia as it does in the case of English-speaking patients. These findings indicate that the NAVS-C is a useful tool for detailing deficit patterns associated with syntactic processing in patients with aphasia cross-linguistically.

German Language Adaptation of the NAVS (NAVS-G) and of the NAT (NAT-G): Testing Grammar in Aphasia

“…Over the past thirty years, behavioral and functional imaging studies have confirmed linguistic claims concerning syntactic complexity in healthy children, in children with syntactic language impairments [24,28,29] and in healthy participants, both behaviorally and using functional imaging [30][31][32][33]. Syntactic complexity also affects verb and sentence processing in stroke-induced aphasia-an acquired language disorder often resulting from lesions within the language network [34][35][36][37]. Studies show that patients with Broca's aphasia and concomitant agrammatism are particularly affected by syntactic complexity [8,34,37,38].…”

“…The validity of the original NAVS is supported by standardization procedures and psychometric data for test validity and reliability that are provided in the respective manual. Several publications have reported the results of testing different populations and languages with the NAVS and NAT: English [8,102,103], Italian [7], and Chinese [36]. All studies have shown that both NAVS and NAT can detect and measure syntactic deficits in stroke patients and patients with primary progressive aphasia.…”

“…Studies show that patients with Broca's aphasia and concomitant agrammatism are particularly affected by syntactic complexity [8,34,37,38]. However, several studies have also documented difficulties in comprehension and production of verbs and sentences with increasing complexity in patients with anomic or Wernicke's aphasia, indicating that such deficits are not limited to Broca's aphasia [8,36,[38][39][40]. In the same way that selective lesions of Broca's region can induce mild, transient aphasia but not agrammatism [40], patients with lesions outside of Broca's area may show grammatical impairments [38][39][40].…”

“…The results of the original version have shown that NAVS is sensitive to capturing syntactic processing in English-speaking people with aphasia [8]. Currently, there are Italian and Chinese versions of the NAVS (NAVS-I [7] and NAVS-C [36], respectively). All versions have confirmed verb deficit and impairment at the sentence level in both comprehension and production, reflecting syntactic complexity hierarchies in patients with aphasia.…”

“…Characterizing residual language deficits in mild forms of aphasia is often challenging, due to the lack of diagnostic tests that are sensitive to aspects of verb and sentence complexity that are known to affect both production and comprehension (see above). Thus, detecting grammatical impairments in individuals with residual aphasia would ensure that the NAVS-G and NAT-G are sufficiently sensitive to be used with individuals with frank agrammatism or anomia, as shown for the original versions and for their adaptations [7,8,36,102].…”