The Use of Linguistic Cues in Sentence Comprehension by Mandarin ...

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Nov 9, 2016 - by Mandarin-Speaking Children with High-Functioning Autism. Peng Zhou1 ..... BEI-constructions by 5-year-old typically developing Mandarin-.
The Use of Linguistic Cues in Sentence Comprehension by Mandarin-Speaking Children with High-Functioning Autism

Peng Zhou, Stephen Crain, Liqun Gao & Meixiang Jia

Journal of Autism and Developmental Disorders ISSN 0162-3257 Volume 47 Number 1 J Autism Dev Disord (2017) 47:17-32 DOI 10.1007/s10803-016-2912-4

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Author's personal copy J Autism Dev Disord (2017) 47:17–32 DOI 10.1007/s10803-016-2912-4

ORIGINAL PAPER

The Use of Linguistic Cues in Sentence Comprehension by Mandarin-Speaking Children with High-Functioning Autism Peng Zhou1 · Stephen Crain2 · Liqun Gao3 · Meixiang Jia4 

Published online: 9 November 2016 © Springer Science+Business Media New York 2016

Abstract Two studies were conducted to investigate how high-functioning children with autism use different linguistic cues in sentence comprehension. Two types of linguistic cues were investigated: word order and morphosyntactic cues. The results show that children with autism can use both types of cues in sentence comprehension. However, compared to age-matched typically developing peers, children with autism relied significantly more on word order cues and exhibited significantly more difficulties in interpreting sentences in which there was a conflict between the morphosyntactic cue and the word order cue. We attribute the difficulties exhibited by children with autism to their deficits in executive function. We then discuss the implications of the findings for understanding the nature of the sentence processing mechanism in autism. Keywords Autism · Sentence comprehension · Linguistic cues · Word order · Executive function · Child language

* Peng Zhou [email protected] 1

Department of Foreign Languages and Literatures, Tsinghua University, Beijing 100084, China

2

Macquarie University, Sydney, NSW 2109, Australia

3

Beijing Language and Culture University, Beijing 100083, China

4

Peking University Sixth Hospital, Beijing 100083, China

Introduction Consider the sentence The dog pushed the cat. This sentence describes a pushing event in which the dog is the initiator of the event and the cat is the recipient of the event. We refer to the dog as the agent and the cat as the patient. In linguistics, these terms (e.g., agent, patient) are referred to as thematic roles, terms that are used to express the semantic role played by a noun phrase (NP) in the action/ event described by the verb phrase (VP). Understanding the thematic roles of NPs in a sentence (i.e., who did what to whom) is one of the basic problems facing language learners. For example, in order to understand an active sentence like The dog pushed the cat, a learner of English will need to decide that in the sentence the first NP the dog is mapped onto an agent role and the second NP the cat is mapped onto a patient role. However, if given a passive structure like The dog is pushed by the cat, the same learner of English will need to understand that the thematic roles of the same NPs are reversed, i.e., the first NP the dog has now become the patient, and the second NP the cat has become the agent. The present study investigates how children with autism understand the thematic roles of NPs in a sentence and what linguistic cues and strategies they use to establish the thematic roles of NPs in sentence comprehension. Language comprehension involves the rapid integration of different types of linguistic and non-linguistic information. Previous research suggests that the language comprehension abilities of children with autism might be particularly impaired (Boucher 2012; Eigsti et al. 2007, 2011; Howlin 2003; Hudry et al. 2010; Koning and Magill-Evans 2001; Kover et  al. 2014; Rapin and Dunn 2003; Saalasti et al. 2008; Seung 2007; Tager-Flusberg 1981; Tager-Flusberg et  al. 2005). However, there is a paucity of research investigating the mechanism underlying the poor language

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comprehension in autism. It still remains largely unclear how children with autism process a sentence using both linguistic and non-linguistic cues and what strategies they employ to understand a sentence. One strategy that has been observed in children with autism when interpreting a sentence is the word-order strategy, whereby they assign the thematic roles to NPs on the basis of the surface order of these NPs in the sentence. For example, TagerFlusberg (1981) found that children with autism tended to interpret noun-verb-noun sequences as encoding agentaction-patient thematic relations. This word-order strategy led children with autism to correctly interpret active sentences like The boy pushes the girl. However, it led to misinterpretations of passive structures like The boy is pushed by the girl. Using an act-out task, Tager-Flusberg found that when presented with the example passive structure, many children with autism consistently acted out an event in which the boy pushed the girl. This finding indicated that children with autism still assigned an agent role to the boy and a patient role to the girl when processing the passive structure The boy is pushed by the girl. Similar findings were reported in Perovic, Modyanova and Wexler (2007, 2013). Using a picture selection task, Perovic and colleagues investigated how children with autism interpreted passive structures like Homer is pushed. In the task, children were presented with two pictures, one depicting an event corresponding to the target interpretation of the sentence (e.g., an event in which Homer is pushed by Marge), and one describing an event in which the thematic roles of the two characters were reversed (e.g., an event in which Homer pushes Marge). It was found that children with autism chose the correct pictures only 36 % of the time. For example, when hearing a sentence like Homer is pushed, children with autism chose the picture of Homer pushing Marge rather than the picture in which Homer is pushed by Marge. This finding is in line with the finding by Tager-Flusberg (1981), indicating that children with autism use a word-order strategy when assigning thematic roles to NPs in a sentence, thus exhibiting a tendency to interpret the first mentioned NP in a sentence as the agent (cf., Gavarró and Heshmati 2014; Paul et al. 1988; Stockbridge et al. 2014; Terzi et al. 2014). The same word-order strategy has long been observed in much younger typically developing (TD) children (de Villiers and de Villiers 1973; Naigles 1996; Sinclair and Bronckart 1972; Slobin 1973). As compared to TD children, however, children with autism exhibit a protracted use of this word-order strategy, e.g., their tendency to interpret the first NP as the agent continued into adolescence, as observed in Riches et  al. (2012) and Tager-Flusberg (1981). For example, Riches et  al. (2002) found that even adolescents with autism exhibited a strong tendency to interpret the first NP of a compound noun as the agent of the action indicated by

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the verb. When presented with a compound noun like donkey kicker while viewing two pictures, one depicting an event in which the donkey is kicking someone and the other depicting an event in which the donkey is being kicked by someone, adolescents with autism were found to be more likely to choose the picture in which the donkey is kicking someone as the correct description of the compound noun donkey kicker. In addition, children with autism might overly rely on this word-order strategy, especially when they process difficult sentences like passive structures, thus exhibiting more misinterpretations compared to TD children, as observed in Perovic, Modyanova and Wexler (2007, 2013). Most of these previous studies are limited to Englishspeaking children with autism. Therefore, it is unclear whether these findings are specific to English, or they can be generalised to other languages. Cross-linguistic investigations are necessary in order to see whether or not this word-order strategy holds for children with autism across languages. Cross-linguistic investigations have proven helpful and illuminating in exploring the nature of language impairment in the general autism population across languages and countries (Su et  al. 2014, Su and Su 2015; Terzi et al. 2014; Zhou et al. 2015). In addition, most previous research focused on one type of linguistic cues—the word order cue. It remains to be investigated whether or not children with autism can use other linguistic cues in sentence comprehension. Exploring how children with autism use different types of linguistic cues in sentence comprehension promises to provide insights into the nature of the poor sentence comprehension in autism, i.e., whether it is due to deficits in linguistic knowledge, or due to impairments in other cognitive functions (e.g., working memory, executive function). To our knowledge, few studies have rigorously sought to identify the factors (both linguistic and non-linguistic) that contribute to the sentence comprehension difficulties observed in children with autism. To shed further light on this topic, the present studies investigate how children with autism understand the thematic roles of NPs in a sentence and whether they are able to use morphosyntactic cues to facilitate the assignment of thematic roles. In particular, we are interested to see whether children with autism can correctly assign thematic roles to NPs in passive structures in which the morphosyntactic cue and the word order cue lead to different thematic role assignments. To anticipate our results, we found that children with autism exhibited great difficulties in interpreting passive structures where there was a conflict between the morphosyntactic cue and the word order cue (Experiment 1). Then we explored the two possibilities that might account for their comprehension difficulties (Experiment 2). One possibility is that children with autism assigned thematic roles to NPs simply based on the word order of the NPs in the

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structures and they were not able to use the morphosyntactic cue at all. The other possibility is that children with autism can use the morphosyntactic cue, but they had difficulties in using the cue when processing a passive structure. Note that in a passive structure, the correct interpretation indicated by the morphosyntactic cue contradicts the interpretation led by the word order cue, thus in order to correctly interpret a passive structure, children first need to pay attention to the morphosyntactic cue, and then use the cue to reanalyse the thematic roles of the NPs indicated by the word order cue. Either of the two steps might pose difficulties for children with autism. They could either fail to pay attention to the morphosyntactic cue, or to reanalyse the thematic roles using the morphosyntactic cue, or possibly both.1 The findings of Experiment 2 provided evidence for this second possibility. As far as we know, the present paper is the first to explore how children with autism use different linguistic cues in sentence comprehension and what are the sources of their impairments in sentence comprehension. We focus our investigations on Mandarin-speaking children with high functioning autism (HFA). Mandarin is ideally suited for investigating these research questions, which we discuss below. Like English, Mandarin has a basic subject-verb-object (SVO) word order (Sun and Givón 1985). Thus, as in English, the first NP of a Mandarin active sentence is typically an agent. Example (1) gives a typical Mandarin SVO sentence in which the first NP Xiaoyang ‘lamb’ is the agent and the second NP Xiaoniu ‘cow’ is the patient. However, unlike English, Mandarin also allows noun-noun-verb (NNV) constructions that often co-occur with the morphosyntactic markers BA and BEI. The two markers appear between the two NPs and disambiguate the thematic roles of the two adjacent NPs (Li 1990; Li et  al. 1992; Li and Thompson 1981). Consider the examples in (2). In (2a), the morphosyntactic marker BA occurs between the first NP Xiaoyang ‘lamb’ and the second NP Xiaoniu ‘cow’, indicating that the first NP Xiaoyang ‘lamb’ is the agent and the second NP Xiaoniu ‘cow’ is the patient. So (2a) means that the lamb kicked the cow. But if the morphosyntactic marker BA is replaced with BEI, as in (2b), then the thematic roles of the two NPs are reversed such that the first NP Xiaoyang ‘lamb’ now becomes the patient and the second NP Xiaoniu ‘cow’ becomes the agent. Thus, (2b) means that the lamb was 1

We thank one of the anonymous reviewers for pointing out these possibilities. We also wish to note that the term “reanalysis” entails “paying attention”, because in order to reanalyse the thematic roles, children first have to pay attention to the morphosyntactic cues. Thereafter we will use the phrase “children’s difficulties with reanalysis” to indicate all the three possibilities: they fail to pay attention to the morphosyntactic cue, or they fail to reanalyse the thematic roles using the morphosyntactic cue, or both, just for ease of explanation.

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kicked by the cow. Both markers are reliable morphosyntactic cues2 to thematic role assignment as schematically represented in (3): the use of BA indicates that the NP preceding it receives the agent role and the NP following it receives the patient role; by contrast, the occurrence of BEI indicates that the NP before it receives the patient role and the NP after it receives the agent role. (1)

(2)

Xiaoyang ti-le xiaoniu. lamb kick-PERF3 cow. Meaning: The lamb kicked the cow.

a.

Xiaoyang BA xiaoniu ti-le lamb BA cow kick-PERF Meaning: The lamb kicked the cow. Xiaoyang BEI xiaoniu ti-le lamb BEI cow kick-PERF Meaning: The lamb was kicked by the cow.

b.

(3)

a. b.

[NP]Agent [NP]Patient

+ +

BA BEI

+ +

guoqu. away guoqu. away

[NP]Patient [NP]Agent

In the present studies, we take advantage of the contrast between the two morphosyntactic markers to investigate whether children with HFA are able to use the information encoded in the two markers to facilitate their sentence comprehension.4 More specifically, the question we ask is: when children with autism hear sentences like (2a) and (2b), will they be able to activate the information encoded in the two markers, as represented in (3), to correctly assign the thematic roles to the NPs in the sentences. We refer to the structures containing BA as BA-constructions and the ones containing BEI as BEI-constructions. Note that in BA-constructions, the morphosyntactic cue and the word order cue lead to the same thematic role assignment (i.e., 2

We refer to BA and BEI as morphosyntactic markers instead of case markers, as would be typically found in Indo-European languages, because BA and BEI are free standing morphemes. Unlike morphological markers in Indo-European languages, BA and BEI do not constitute an integral part of the words with which they occur, i.e., they are not bound to the words they modify and do not undergo phonological assimilations to the words. But, functionally, BA and BEI are equivalent to the case markers in Indo-European languages. 3

Throughout the text, PERF is used to indicate a perfective morpheme in Mandarin Chinese. In Mandarin, the perfective morpheme –le (see (1)) indicates the completion of an event. 4 Huang et  al. (2013) investigated the comprehension of BA- and BEI-constructions by 5-year-old typically developing Mandarinspeaking children. Their studies focused on typically developing children’s online sentence comprehension and used the visual world paradigm of eye tracking. Since the research focus and methodologies between their studies and ours are very different, the details of their studies are not reviewed here.

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both assign the agent role to the first NP and the patient role to the second NP), whereas in BEI-constructions, the morphosyntactic cue and the word order cue lead to different thematic role assignments (i.e., the morphosyntactic marker BEI assigns the patient role to the first NP and the agent role to the second NP, but the word order cue still assigns the agent role to the first NP and the patient role to the second NP). So in order to correctly interpret BEI-constructions, children need to use the information provided by BEI to override the information provided by the word order cue. More specifically, to correctly interpret BEI-constructions like (2b), children need to reanalyse the thematic role of the first NP from the agent role (based on the word order cue) to the patient role when later encountering the morphosyntactic marker BEI. Two experiments were conducted. In the first experiment, we were interested to see (i) whether or not Mandarin-speaking children with autism use the same word-order strategy as their English counterparts do in assigning thematic roles to NPs in a sentence, thus exhibiting a tendency to interpret the first NP as the agent; and (ii) if Mandarinspeaking children with autism exhibit a tendency to assign the agent role to the first NP in BEI-constructions where it receives the patient role, are they able to revise their initial analysis using the information provided by the morphosyntactic marker BEI? As discussed earlier, the results of the first experiment confirmed that Mandarin-speaking children with autism exhibited difficulties in interpreting the BEI-constructions where there was conflict between the word order cue and the morphosyntactic cue. So, a second experiment was conducted to explore the factors that might have contributed to their poor comprehension of passive structures. More specifically, we asked the question: if no reanalysis is required to correctly assign the thematic roles of NPs in a passive structure, would children with autism be able to correctly interpret the sentence? One such case would be a structure in which the morphosyntactic cue occurs before the word order cue, and the use of the morphosyntactic cue leads to the correct thematic role assignment. Mandarin provides such an ideal case. We take advantage of a special property of Mandarin that it is a pro-drop language in which the subject NP of a sentence can often be omitted when it is contextually available. So, for example, the subject NPs of the BA- and BEIconstructions in (2a) and (2b) can often be omitted, thus yielding a new BA-construction in (4a) and a new BEI-construction in (4b). Although the subject NPs are omitted in (4a) and (4b), the structures of their thematic role assignment remain the same as their corresponding constructions in (2a) and (2b). Again, both BA and BEI are reliable

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morphosyntactic cues to thematic role assignment as schematically represented in (5): the use of BA indicates that the NP following it receives the patient role and the omitted subject NP receives the agent role; whereas the use of BEI indicates that the NP following it receives the agent role and the omitted subject NP receives the patient role. So in (4a) the NP the cow is the patient, meaning that someone kicked the cow. By contrast, in (4b) the same NP the cow becomes the agent, meaning that someone was kicked by the cow. (4)

a.

BA xiaoniu ti-le BA cow kick-PERF Meaning: Someone kicked the cow. BEI xiaoniu ti-le BEI cow kick-PERF Meaning: Someone was kicked by the cow.

b.

(5)

a. b.

BA BEI

+ +

guoqu. away guoqu. away

[NP]Patient [NP]Agent

In both (4a) and (4b), the morphosyntactic marker appears before the NP in the sentence. Therefore, the first cue that children would hear in these constructions is the morphosyntactic cue, and the use of the morphosyntactic cue would lead to the correct interpretation. No reanalysis of thematic roles is required. In the second experiment, we were interested to find out whether or not Mandarin-speaking children with HFA are able to use morphosyntactic cues to correctly assign thematic roles to NPs in constructions like (4a) and (4b), and in particular, in BEI-constructions as in (4b) where no reanalysis is required to overcome the word order bias. To summarise, the present paper reports findings from two experiments investigating how Mandarin-speaking children with HFA and their age-matched TD peers use morphosyntactic and word order cues in sentence comprehension. Experiment 1 used minimal pairs as in (2a) and (2b). Experiment 2 took advantage of minimal pairs as in (4a) and (4b). In order to process constructions as in (4a) and (4b), children need to understand that Mandarin is a pro-drop language in which the subject NP of a sentence can often be omitted. It has been reported that by 3 years of age, TD Mandarin-speaking children already acquire the pro-drop property of Mandarin, and their subject-dropping rate is very close to that of Mandarin-speaking adults (Wang et al. 1992). The findings of the present studies will help us better understand the features of the sentence processing mechanism in autism.

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General Method Participants Eighty Mandarin-speaking children with HFA participated in the experimental studies. They were recruited from the Rehabilitation and Education Centre for Children with Autism, affiliated with the Peking University Sixth Hospital, Beijing, China. Their diagnoses were made by paediatric neurologists at the Peking University Sixth Hospital prior to enrolment to the Centre. To confirm the participants’ diagnoses, an expert clinician was asked to observe these children to ensure that they met the DSM-IV-TR (APA, 2000) criteria for autistic disorder. Two children did not proceed to the actual experiment, because they did not meet the DSMIV-TR criteria for autistic disorder. Two additional children did not complete the experimental tasks. The remaining 76 children all met the DSM-IV-TR criteria for autistic disorder, and none of them were diagnosed with Asperger’s disorder or with pervasive developmental disorder—not otherwise specified (PDD-NOS). Each of these 76 children was further evaluated independently by our research team using the Autism Diagnostic Observation Schedule (ADOS; Lord et  al. 1999). In order to reduce the variability in the participants, we only included participants who were confirmed to meet the diagnostic criteria for autistic disorder by the expert clinician and also met the autism cut-off on the ADOS. One child did not meet the autism cut-off on the ADOS. The other 75 children all met the autism cut-off on the ADOS, and thus were included in the final analyses: 36 children were between the ages of 4; 3 (years; months) and 4; 9 (mean age 4; 5), 39 children were between the ages of 5; 2 and 5; 9 (mean age 5; 5). In addition, 80 age-matched TD children also participated in the studies: 41 children were between the ages of 4; 2 and 4; 10 (mean age 4; 5) and 39 children were between the ages of 5; 2 and 5; 10 (mean 5; 5). They were recruited from the kindergarten at the Beijing Language and Culture University, Beijing, China. The participants’ verbal IQ was assessed using the Chinese-Wechsler Young Children Scale of Intelligence (C-WYCSI)—a standardised IQ test designed for Mandarin-speaking children between the ages of 4 and 6.5 (Gong Table 1 Verbal IQ scores and MLU of each participant group

and Dai 1992). The test showed that all the participants, including both the children with HFA and the TD children, had verbal IQ scores above 90. In addition, in order to assess children’s sentence complexity levels, we measured the Mean Length of Utterance (MLU) of each participant. We recorded 100 utterances for each participant. The participants’ utterances were recorded from their interactions with their teachers either in classroom or individual training sessions. In Mandarin, MLU was often calculated by dividing the total number of words by the number of utterances in each speech sample. In the present experimental studies, we followed the common practice of calculating Mandarin MLU by dividing the total number of words in each participant’s utterances by the total 100 utterances that were recorded for each participant. The mean IQ score and MLU for each participant group are presented in Table 1. Differences were observed between the two autism groups and their age-matched TD peers in IQ scores and MLU levels. The 4-year-olds with autism and the 5-yearolds with autism had an IQ score that was significantly lower than that of their age-matched TD groups, i.e., 4-year-olds with autism versus TD 4-year-olds, t(75) = 4.25, p < .01, d = 0.24; 5-year-olds with autism versus TD 5-yearolds, t(76) = 3.68, p < .01, d = 0.19. But the IQ scores of the 5-year-olds with autism were comparable with those of the younger TD group—TD 4-year-olds, t(78) = 1.27, p = .55, d = 0.03. With respect to MLU levels, the two autism groups had an MLU level that was significantly lower than that of their age-matched TD peers, 4-year-olds with autism versus TD 4-year-olds, t(75) = 15.09, p < .001, d = 0.70; 5-year-olds with autism versus TD 5-year-olds, t(76) = 11.16, p < .001, d = 0.60. However, the MLU levels of the 5-year-olds with autism were comparable with those of the younger TD group—TD 4-year-olds, t(78) = 0.87, p = .23, d = 0.07. Participants in each of the four groups were randomly assigned to one of the two experiments. Experiment 1 consisted of 18 4-year-olds with autism, 20 5-year-olds with autism, 20 TD 4-year-olds and 19 TD 5-year-olds. Experiment 2 consisted of 18 4-year-olds with autism, 19 5-year-olds with autism, 21 TD 4-year-olds, and 20 TD 5-year-olds. None of the participants in Experiment 2 had

HFA

Verbal IQ  Mean (SD)  Range MLU  Mean (SD)  Range

TD

4-yr-olds

5-yr-olds

4-yr-olds

5-yr-olds

98.37 (13.43) 91–125

101.26 (12.64) 92–134

101.67 (13.78) 92–135

103.62 (11.87) 94–138

4.87 (1.34) 4.50–5.00

5.89 (1.36) 5.50–6.05

5.80 (1.32) 5.50–6.00

6.68 (1.27) 6.50–7.06

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Table 2 Verbal IQ scores and MLU of each participant group in the two experiments after the random assignment

HFA

Verbal IQ in exp1  Mean (SD)  Range Verbal IQ in exp2  Mean (SD)  Range MLU in exp1  Mean (SD)  Range MLU in exp2  Mean (SD)  Range

4-yr-olds

5-yr-olds

4-yr-olds

5-yr-olds

98.31 (13.78) 91–124

101.33 (12.53) 94–134

101.54 (13.08) 93–135

103.83 (12.23) 94–137

98.43 (13.14) 93–125

101.19 (12.47) 92–133

101.80 (13.88) 92–134

103.41 (12.68) 94–138

4.86 (1.31) 4.60–5.00

5.90 (1.37) 5.50–6.05

5.78 (1.28) 5.50–6.00

6.77 (1.29) 6.50–7.06

4.88 (1.35) 4.50–5.00

5.88 (1.33) 5.50–6.00

5.82 (1.34) 5.55–6.00

6.59 (1.30) 6.50–7.05

participated in Experiment 1. The mean IQ score and MLU for each participant group in the two experiments can be found in Table  2. As indicated in Table  2, the subgroups in Experiment 1 were comparable with the subgroups in Experiment 2 on verbal IQ scores and MLU levels after the random assignment. Procedures Both Experiment 1 and Experiment 2 used a picture selection task. In the task, the participants were presented with a spoken sentence while viewing a visual image containing two pictures. Participants were told that they were going to see some pictures, and the puppet (Kermit the Frog) was going to explain to them what he saw in the pictures. On each trial, the participant’s task was to decide which picture the puppet was talking about, either by pointing to the correct picture or by a verbal mention of the correct picture. The picture stimuli were displayed on the screen of a laptop computer. Spoken sentences were presented to the participants through the laptop computer connected to two external speakers. Before the actual experiment, we had an introduction session to familiarise the participants with the experimental procedure as well as the animals that were presented in the pictures. The introduction session was followed by the experimental session. The experimental session began with four practice trials followed by 24 test trials (12 target and 12 filler trials). Like the target and filler trials, each practice trial consisted of a visual image and a spoken sentence. On two of the practice trials the spoken sentence was compatible with the picture in the upper panel of the visual image, and on the other two the spoken sentence matched the picture in the lower panel. Before each trial, a picture of Kermit the Frog was presented at the centre of the computer screen, which

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TD

anchored the beginning of each trial, and served to capture the participants’ attention. The picture was also used to make it appear that the puppet was talking. The participants were introduced to the task individually and were tested individually. Only those children who correctly chose the picture that matched the corresponding spoken sentence on the practice trials were permitted to advance to the experimental session.

Experiment 1 Experiment 1 investigated how Mandarin-speaking children with HFA interpret BA- and BEI-constructions as in (2a) and (2b), repeated here as (6a) and (6b). (6)

a.

Xiaoyang BA xiaoniu ti-le lamb BA cow kick-PERF Meaning: The lamb kicked the cow.

guoqu. away

b.

Xiaoyang

guoqu.

BEI

xiaoniu

ti-le

lamb BEI cow kick-PERF Meaning: The lamb was kicked by the cow.

away

Materials and Design A total of 12 target items were constructed each consisting of a visual image and two spoken sentences, one with the morphosyntactic marker BA and one with the morphosyntactic marker BEI. Each visual image contained two pictures, both of which described the same event involving the same two characters (e.g., a kicking event involving the lamb and the cow), but the thematic roles of the two characters in the event were reversed in the two pictures (e.g.,

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in one picture the lamb was the agent and the cow was the patient, but in the other picture the roles were reversed). In order to control for potential preferences for selecting particular displayed objects, the position of the target pictures that corresponded to the target sentence was counterbalanced across trials. On half of the trials, the target picture that matched the BA-construction was in the upper panel of the visual image and the one that matched the BEI-construction was in the lower panel. On the other half of the trials, the position was reversed. In addition, we controlled for the animacy effect. As Corrigan (1988) has shown, when there is an animate-inanimate contrast involved in an event, people tend to assign the agent role to the animate NP and the patient role to the inanimate NP. To avoid this animacy bias, we used animate NPs for both the agent and the patient involved in the event. More specifically, the two characters in the event depicted in the visual image were both animal characters, and there were equal probabilities for both animal characters to perform actions on the other. In other words, the two characters were equally likely to be the agent or the patient. All the spoken sentences had the same structure: Subject NP + Morphosyntactic Marker + Object NP + VP. The morphosyntactic marker was either BA or BEI. The subject NP was always a disyllabic word in Mandarin, and was about an animal. The object NP was also a disyllabic word about an animal. The VP was always a foursyllable word in Mandarin. To ensure that the participants were familiar with the nouns and the verbs we used, all the nouns and verbs used in the target sentences were assessed by the participants’ teachers at the Rehabilitation and

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Education Centre for Children with Autism, or at the kindergarten at the Beijing Language and Culture University, where the experiments were conducted. All the words were printed out on a piece of paper, and for each individual word the teachers were asked to judge whether their students were familiar with it. All the words were judged by the teachers to be familiar to the participants. To describe one visual image in detail (see Fig.  1): it contained two pictures, the one in the upper panel depicted a kicking event in which the lamb is the agent and the cow is the patient, and the one in the lower panel also described a kicking event but the thematic roles of the two characters were reversed: in this picture the lamb is the patient and the cow is the agent. For this image, two spoken sentences were recorded as in (6), one BA-construction as in (6a), and one BEI-construction as in (6b). Except for the morphosyntactic markers, the other words in (6a) and (6b) were exactly the same. The 12 target items were divided into two lists with each participant seeing each visual image but hearing only one of the two spoken sentences that could accompany the visual image. The BA- and BEI-constructions were counterbalanced across the two lists with 6 BAconstructions and 6 BEI-constructions in each list. In addition, 12 filler items were added to each experimental list. Each filler item consisted of a visual image and a spoken sentence. On half of the filler trials the spoken sentence represented the picture in the upper panel of the visual image, and on the other half the spoken sentence was compatible with the picture in the lower panel. The pictures on the filler trials were similar to the pictures on the target trials. An example of the visual images can be found in Appendix 1, where the upper panel depicted a holding event in which the cat is the agent and the rabbit is the patient, and the lower panel also depicted a holding event involving the cat and the rabbit, but the thematic roles of the two animal characters were reversed: the cat becomes the patient and the rabbit becomes the agent. The spoken sentence corresponding to the example filler image is given in (7), which is a simple SVO sentence and is a representation of the picture in the lower panel. All the filler sentences were simple SVO sentences like (7). These filler items were also used to see whether children understand simple SVO structures. (7)

Fig. 1 Example visual image used in the experiments

Tuzi ju-le rabbit hold-PERF Meaning: The rabbit held the cat.

xiaomao. cat

In each experimental list, the 12 target and 12 filler items were arranged in random order. The participants were randomly assigned to one of the two lists. A full list of the target sentences is included in Appendix 2. All the target

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and filler sentences were pre-recorded and were produced by a female native speaker of Beijing Mandarin. She was asked to produce the test sentences in a child-directed manner. The recording was conducted in a sound-attenuated recording booth at Macquarie University.

Predictions If Mandarin-speaking children with HFA use the wordorder strategy as their English counterparts do, when assigning thematic roles to NPs in a sentence, then they would be expected to correctly choose the pictures that matched the BA-constructions, because the correct interpretation indicated by the morphosyntactic marker BA is consistent with the interpretation indicated by the word order cue. So, on the example trial, when hearing the BA-construction in (6a), children with autism would be expected to choose the picture in which the lamb kicked the cow (the upper panel of Fig. 1). However, children with autism would be expected to exhibit difficulties when hearing the BEI-constructions, because the interpretation led by the morphosyntactic marker BEI contradicts the interpretation led by the word order cue. Suppose that children with autism use the word-order strategy and are not able to reanalyse the first NP as the patient when hearing the morphosyntactic marker BEI. If so, then they might incorrectly choose the picture that matched the BA-construction instead of the BEI-construction. On the example trial, when presented with the BEI-construction in (6b), children with autism would be expected to incorrectly choose the picture in which the lamb kicked the cow (the upper panel of Fig.  1) rather than the correct picture where the lamb was kicked by the cow (the lower panel of Fig. 1).

Results The dependent measure was the proportion of responses in which the participants correctly chose the picture that matched the spoken sentence in each condition. Most of the participants’ responses were a point at the correct picture. Some of the participants gave a verbal mention of the correct picture accompanied by a point at the picture. Each participant’s responses were recorded at the time of the study by both the experimenter and the teacher of the participant. The experimenter and the teacher were 100 % consistent with their judgements of the participants’ choices. In response to the filler trials, all the participants, including both children in the autism group and in the TD group, correctly chose the pictures that matched the corresponding spoken sentences above 98 % of the time, indicating that both the children with HFA and TD children could correctly interpret simple SVO sentences. So they were all included in the final analyses.

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J Autism Dev Disord (2017) 47:17–32 Table 3 Mean proportions of correct responses to the two types of constructions by the autism and TD children (SD in parentheses) in the two experiments Group Autism group in exp1  4-year-olds  5-year-olds Autism group in exp2  4-year-olds  5-year-olds TD group in exp1  4-year-olds  5-year-olds TD group in exp2  4-year-olds  5-year-olds

BA-constructions

BEI-constructions

93.52 % (12.14) 95.00 % (11.17)

21.30 % (12.66) 24.17 % (13.12)

93.52 % (10.12) 93.86 % (12.02)

87.04 % (11.34) 88.60 % (12.04)

98.33 % (6.14) 99.12 % (5.02)

89.17 % (9.71) 94.74 % (10.04)

95.24 % (5.13) 99.17 % (5.07)

94.44 % (8.81) 98.33 % (9.76)

There were two types of target sentences, the BA-construction and the BEI-construction. Proportions of the correct responses to the two types of constructions were computed for each age group in both the autism and TD populations (see Table  3). Following the standard statistical procedure, in the analyses we calculated effect size with Cohen’s d for t tests. Effect sizes between 0.2 and 0.5 are considered small, between 0.5 and 0.8 medium, and above 0.8 large. We calculated effect size with partial eta squared (η2) for the repeated measures ANOVAs. Values between 0.01 and 0.06 are considered a small effect size, between 0.06 and 0.14 a medium effect size, and above 0.14 a large effect size. Within-Group Comparisons As indicated in Table  3, the two autism groups exhibited similar response patterns. Both the 4-year-olds with autism and the 5-year-olds with autism responded correctly to the BA-constructions more often than the BEI-constructions. When hearing the BA-constructions, the 4-year-olds with autism correctly chose the corresponding pictures 93.52 % of the time. But when presented with the BEI-constructions, they correctly chose the corresponding pictures only 21.30 % of the time; the other 78.70 % of the time they incorrectly chose the pictures that matched the BA-constructions. On the example trial, when presented with the BA-construction in (6a), the children with autism correctly chose the picture in the upper panel of Fig. 1; but when hearing the BEI-construction in (6b), most of the children still chose the picture in the upper panel of Fig. 1, which was an incorrect description of (6b). This difference between the two conditions reached statistical significance, 93.52 vs. 21.30 %, t(17) = 5.65, p < .001, d = 5.82. The 5-year-olds with autism also provided significantly more correct responses to the BA-constructions than to the BEI-constructions, 95.00 vs. 24.17 %, t(19) = 5.80,

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p < .001, d = 5.81. When hearing the BA-constructions, the 5-year-olds with autism correctly chose the corresponding pictures 95.00 % of the time. But when presented with the BEI-constructions, they correctly chose the corresponding pictures only 24.17 % of the time; the other 75.83 % of the time they incorrectly chose the pictures that were compatible with the BA-constructions. By contrast, the two TD groups responded to the BA- and BEI-constructions equally well. The TD 4-year-olds correctly chose the pictures that matched the BA-constructions 98.33 % of the time, and they correctly chose the pictures that matched the BEI-constructions 89.17 % of the time. There was no significant difference between their proportions of correct responses to the two types of constructions, t(19) = 1.45, p = .16, d = 1.13. The TD 5-year-olds also responded equally well to the BA- and BEIconstructions, 99.12 vs. 94.74 %, t(18) = 1, p = .33, d = 0.55. Between-Group Comparisons To compare the responses to the two types of target constructions by the autism group (combining the 4-year-olds with autism and the 5-year-olds with autism) versus the age-matched TD group (combining the TD 4-year-olds and 5-year-olds), a repeated measures ANOVA was performed with sentence type (i.e., the BA-construction versus the BEIconstruction) as the within-subjects factor. There was a significant main effect of sentence type, F(1, 75) = 68.83, p < .001, η2 = 0.48. There was also a significant interaction between group and sentence type, F(1, 75) = 46.89, p < .001, η2 = 0.39. Post-hoc pairwise comparisons showed that the autism group responded correctly to the BEI-constructions significantly less often than their age-matched TD group, t(75) = 8.66, p < .001, d = 5.87, but the two groups responded equally well to the BA-constructions, t(75) = 1.19, p = .24, d = 0.53. As discussed, the 5-year-olds with autism were comparable on both verbal IQ and MLU with the TD 4-year-olds (see Table  1). So, comparisons were performed on the two IQand MLU-matched groups in their responses to the two types of target constructions. Again, a repeated measures ANOVA was performed with sentence type as the within-subjects factor. There was a significant main effect of sentence type, F(1, 38) = 33.84, p < .001, η2 = 0.47. There was also a significant interaction between group and sentence type, F(1, 38) = 20.11, p < .001, η2 = 0.35. Post-hoc pairwise comparisons showed that the 5-year-olds with autism responded correctly to the BEI-constructions significantly less often than the IQ- and MLU-matched TD 4-year-olds, t(38) = 5.49, p < .001, d = 5.23, but the two groups responded equally well to the BA-constructions, t(38) = 0.65, p = .52, d = 0.51. The results of the experiment show that the TD 4-yearolds and 5-year-olds were able to correctly assign the thematic roles to the NPs using the information provided by the two markers. By age 4, TD Mandarin-speaking children are

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sensitive to the properties of the two morphosyntactic markers BA and BEI. The 4-year-olds with HFA and the 5-yearolds with HFA correctly assigned the thematic roles to the NPs in the BA-constructions but they exhibited difficulties in correctly assigning the thematic roles to the NPs in the BEIconstructions. Compared to age-matched TD peers, children with HFA chose the correct pictures that matched the corresponding BEI-constructions significantly less often. In addition, children with HFA correctly chose the pictures that matched the BEI-constructions significantly less often than younger TD children matched on IQ and MLU. Instead of choosing the picture that matched the corresponding BEIconstruction, most of the children with HFA incorrectly chose the one that matched the BA-construction. For example, when hearing the BEI-construction in (6b) Xiaoyang BEI xiaoniu ti-le guoqu in which the use of BEI indicates that the subject NP xiaoyang ‘the lamb’ is the patient of the kicking event, and the object NP xiaoniu ‘the cow’ is the agent of the kicking event, most of the children with HFA chose the picture in which xiaoyang ‘the lamb’ is the agent and xiaoniu ‘the cow’ is the patient. This is evidence that Mandarin-speaking children with HFA use the word-order strategy when assigning thematic roles to NPs in a sentence. Like their English-speaking counterparts, Mandarin-speaking children with HFA exhibit a tendency to interpret the first NP as the agent when interpreting a sentence. Experiment 2 Experiment 2 took advantage of the special property of Mandarin that the subject NP of a sentence can often be omitted when it is contextually available. As discussed, the BA-construction in (4a) and the BEI-construction in (4b), repeated here as (8a) and (8b), are perfectly grammatical sentences in Mandarin, though the subject NPs of both structures are omitted. Both BA and BEI in (8a) and (8b) are reliable morphosyntactic cues to thematic role assignment: the use of BA indicates that the NP following it receives the patient role and the omitted subject NP receives the agent role; whereas the use of BEI indicates that the NP following it receives the agent role and the omitted subject NP receives the patient role. (8)

a.

b.

BA xiaoniu ti-le guoqu. BA cow kick-PERF away Meaning: Someone kicked the cow. BEI xiaoniu ti-le guoqu. BEI cow kick-PERF away Meaning: Someone was kicked by the cow.

Experiment 2 investigated the comprehension of the BAand BEI-constructions as in (8a) and (8b) by Mandarinspeaking children with HFA.

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Materials and Design A total of 12 target items were constructed each consisting of a visual image and two spoken sentences, one with the morphosyntactic marker BA and one with the morphosyntactic marker BEI. The only difference between the spoken sentences in this experiment and those used in Experiment 1 is that the subject NPs of the spoken sentences in this experiment were omitted. The visual images used in this experiment were exactly the same as those in Experiment 1. Each visual image contained two pictures, both of which described the same event involving the same two characters, but the thematic roles of the two characters in the event were reversed in the two pictures (see Fig. 1). The 12 target items were divided into two lists with each participant seeing each visual image but hearing only one of the two spoken sentences that could accompany the visual image. The BA- and BEI-constructions were counterbalanced across the two lists with 6 BA-constructions and 6 BEI-constructions in each list. In addition, 12 filler items were added to each experimental list. Each filler item consisted of a visual image and a spoken sentence. On half of the filler trials the spoken sentence matched the picture in the upper panel of the visual image, and on the other half the spoken sentence matched the picture in the lower panel. The pictures on the filler trials were exactly the same as those in Experiment 1. An example of the visual images can be found in Appendix 1. The spoken sentence corresponding to the example filler image is given in (9). (9) is a simple sentence in which the subject NP is omitted. It means that someone held the cat and thus is a representation of the picture in the lower panel. All the filler sentences were simple sentences with the subject NP omitted. The filler items were also used to see whether children understand simple sentences in which the subject NP was omitted. (9)

Ju-le xiaomao. hold-PERF cat Meaning: Someone held the cat.

In each experimental list, the 12 target and 12 filler items were arranged in random order. The participants were randomly assigned to one of the two lists. None of the participants had participated in Experiment 1. A full list of the target sentences is included in Appendix 3. Again, all the target and filler sentences were pre-recorded and were produced by a female native speaker of Beijing Mandarin. Predictions If Mandarin-speaking children with HFA are able to use the morphosyntactic cues to interpret the BA- and

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BEI-constructions when the subject NPs of the constructions are omitted, then they would be expected to respond to the two types of constructions equally well, i.e., correctly choosing the pictures that matched the corresponding BAand BEI-constructions. For example, when presented with the BA-construction in (8a), children would be expected to choose the picture in which the lamb kicked the cow (the upper panel of Fig. 1); and when hearing the BEI-construction in (8b), they should choose the picture where the lamb was kicked by the cow (the lower panel of Fig. 1).

Results Again, each participant’s responses were recorded at the time of the study by both the experimenter and the teacher of the participant. The experimenter and the teacher were 100.00 % consistent with their judgements of the participants’ choices. We computed the proportion of correct responses by both the TD group and the autism group in each condition. In response to the filler trials, all the participants correctly chose the pictures that matched the corresponding spoken sentences above 97.00 % of the time, suggesting that both the children with HFA and TD children could understand simple sentences in which the subject NP was omitted. They have acquired the knowledge that Mandarin is a pro-drop language in which the subject NP of a sentence can often be omitted when it is contextually available. So, all the participants were included in the final analyses. Table 3 gives the proportion of correct responses to the two types of constructions by the two autism groups and the two TD groups. Within-Group Comparisons As indicated in Table  3, both the 4-year-olds with autism and the 5-year-olds with autism responded correctly to the BA- and BEI-constructions equally well. When presented with the BA-constructions, the 4-year-olds with autism correctly chose the corresponding pictures 93.52 % of the time; and when hearing the BEI-constructions, they correctly chose the corresponding pictures 87.04 % of the time. As we expected, on the example trial, when hearing the BA-construction in (8a), the children with autism correctly chose the picture in the upper panel of Fig. 1; and when hearing the BEI-construction in (8b), they correctly chose the picture in the lower panel of Fig.  1. There was no significant difference in the proportions of correct responses across the two conditions, 93.52 vs. 87.04 %, t(17) = 1.16, p = .26, d = 0.60. The 5-year-olds with autism also responded correctly to the BA- and BEI-constructions equally often, 93.86 vs. 88.60 %, t(18) = 1, p = .33, d = 0.44. The two TD

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groups also exhibited similar response patterns. Both the TD 4-year-olds and 5-year-olds responded equally well to the BA- and BEI-constructions. The TD 4-year-olds correctly chose the pictures that matched the BA-constructions 95.24 % of the time, and they correctly chose the pictures that matched the BEI-constructions 94.44 % of the time. There was no significant difference between their proportions of correct responses to the two types of constructions, t(20) = 1, p = .33, d = 0.11. The TD 5-year-olds also responded correctly to the BA- and BEI-constructions equally often, 99.17 vs. 98.33 %, t(19) = 1, p = .33, d = 0.12. Between-Group Comparisons To compare the responses to the two types of target constructions by the autism group (combining the 4-year-olds with autism and the 5-year-olds with autism) versus the age-matched TD group (combining the TD 4-year-olds and 5-year-olds), a repeated measures ANOVA was performed with sentence type (i.e., the BA-construction versus the BEI-construction) as the within-subjects factor. Neither a significant main effect of sentence type, F(1, 76) = 2.26, p = .1, η2 = 0.38, nor a significant interaction between group and sentence type, F(1, 76) = 1.92, p = .17, η2 = 0.42, was observed. Both the autism group and their age-matched TD group responded equally well to the two types of constructions. There were no significant differences between the two groups in their proportions of correct responses to the BA-constructions, t(76) = 0.78, p = .44, d = 0.52, or the BEI-constructions, t(76) = 1.53, p = .13, d = 0.48. Again, we compared the performance of the 5-yearolds with autism and the TD 4-year-olds, because these two groups were matched on both verbal IQ and MLU (see Table 1). A repeated measures ANOVA was performed with sentence type as the within-subjects factor. There was neither a significant main effect of sentence type, F(1, 38) = 1.43, p = .24, η2 = 0.44, nor a significant interaction between group and sentence type, F(1, 38) = 0.78, p = .38, η2 = 0.39. The 5-year-olds with autism and the IQ- and MLU-matched TD 4-year-olds performed equally well when responding to both the BA-constructions, t(38) = 0.19, p = .85, d = 0.61, and the BEI-constructions, t(38) = 0.69, p = .50, d = 0.77. The findings of Experiment 2 show that Mandarin-speaking children with HFA were able to use the morphosyntactic cues to correctly interpret the BA- and BEI-constructions when the subject NPs of the constructions were omitted.

General Discussion In the present paper, we sought to investigate whether 4- and 5-year-old Mandarin-speaking children with HFA are able to use different linguistic cues in sentence

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comprehension. We focused on two types of linguistic cues, word order cues and morphosyntactic cues. It was found that both the 4-year-olds with HFA and 5-year-olds with HFA correctly interpreted the BA-constructions where the interpretation indicated by the morphosyntactic cue is consistent with the interpretation indicated by the world order cue. However, both the 4-year-olds and 5-year-olds exhibited difficulties in interpreting the BEI-constructions in which the interpretation led by the morphosyntactic cue contradicts the interpretation led by the word order cue. When presented with the BEI-construction, most of the children with HFA incorrectly chose the picture that matched the corresponding BA-construction rather than the one that matched the BEI-construction (Experiment 1). Like their English counterparts, Mandarin-speaking children with HFA exhibited a tendency to interpret the first mentioned NP in a sentence as the agent. This finding provides cross-linguistic evidence for the observation by Riches et al. (2012) and Tager-Flusberg (1981) that children with autism use a word-order strategy when interpreting linguistic structures. In fact, our findings suggest that children with autism overly rely on the word order cue such that they are not able to use the morphosyntactic cue to override the incorrect interpretation indicated by the word order cue when interpreting a passive structure. As discussed, there are two possibilities for the misinterpretation of the BEI-constructions in Experiment 1. One is that children with autism were not able to use the morphosyntactic cues at all and they simply based their interpretation on the word order of the NPs in a sentence when assigning thematic roles to these NPs. The other possibility is that children with autism can use the morphosyntactic cue, but they had difficulties in using the cue when processing the BEI-constructions in Experiment 1. Note that in the BEI-constructions, the correct interpretation indicated by the morphosyntactic cue contradicts the interpretation led by the word order cue, thus in order to correctly interpret the BEIconstructions, children first needed to pay attention to the morphosyntactic cue, and then used the cue to reanalyse the thematic roles of the NPs indicated by the word order cue. Either of the two steps might pose difficulties for children with autism. They could either fail to pay attention to the morphosyntactic cue, or to reanalyse the thematic cues using the morphosyntactic cue, or possibly both. The findings of Experiment 2 provided evidence for this second possibility. Taken together, the findings of the two experiments show that 4- and 5-year-old Mandarin-speaking children with HFA are able to use both word order cues and morphosyntactic cues in sentence comprehension. However, compared to their age-matched TD peers, children with HFA rely significantly more on the word order cue and exhibit significantly more difficulties in reanalysing the thematic roles of NPs in a sentence. Once they have assigned

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the thematic roles to the NPs based on the word order cue, they are not able to reanalyse these roles even after they encounter the morphosyntactic cues. For example, when presented with the BEI-constructions in Experiment 1, the children with HFA incorrectly analysed the first NP as the agent based on the word order cue, and they were not able to reanalyse the first NP as the patient even after they heard the morphosyntactic cue BEI. But when the morphosyntactic cue became the first cue that children could use in the sentence, and the use of the cue led to the correct assignment of thematic roles of the NPs, the children with autism became as effective as their age-matched TD peers in using the morphosyntactic cue to arrive at the correct interpretation of the sentence, as shown in Experiment 2. The findings lead us to ask: Why did children with autism overly rely on the word order cue and have particular difficulties with the reanalysis of thematic roles. What are the factors that contribute to this processing feature of children with autism? One might attribute this processing feature to their deficits in linguistic knowledge. More specifically, one could assume that the difficulties with reanalysis exhibited by the children with autism are due to their deficits in representing complex structures like passive structures (e.g., the BEI-constructions). However, we wish to note that, first, the children with HFA in Experiment 1 misinterpreted the BEI-constructions significantly more often even compared to MLU-matched TD children. MLU, to some extent, can be used as an indicator of children’s language development, or at least the development of their sentence complexity. This finding suggests that children with HFA who had the same level of sentence complexity as their TD peers still had difficulties with reanalysis, indicating that the difficulties might be relatively independent of the development of sentence complexity. Second, the children with HFA were as effective as the age-matched and MLU-matched TD children in processing the BEI-constructions in Experiment 2 when no reanalysis was involved. This finding indicates that children with autism can process passive structures correctly. Based on these considerations, it seems quite unlikely that the difficulties with reanalysis are due to their lack of the complex linguistic representations of passive constructions. Another possibility is that the overreliance on the word order cue and the difficulties with reanalysis by the children with autism might be due to their impairments in other cognitive functions. We propose that a deficit in executive function might be a good candidate for explaining this processing feature of children with autism. Executive function refers to higher order, selfregulatory, cognitive processes that aid in the monitoring and control of thought and action. These skills include inhibitory control, planning, attentional flexibility, error

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detection and correction, and resistance to interference (Dempster 1992; Welsh et  al. 1991; Zelazo et  al. 1997). As discussed, previous research has shown that executive function, such as inhibition and working memory, are particularly impaired in children with autism (Bennetto et  al. 1996; Christ et  al. 2007; Hill 2004; Hughes et  al. 1994; Joseph et al. 2005; Luna et al. 2007; Ozonoff et al. 1991; Williams et al. 2005). Research has also suggested that executive function, in particular inhibitory control, plays an important role in sentence processing when the initial interpretation of a sentence is required to be inhibited in place of a later alternative interpretation (e.g., Novick et  al. 2005). In Experiment 1, the correct interpretation of the BEI-constructions requires the revision of the thematic role of the first NP from agent to patient which involves the inhibition of the initial interpretation indicated by the word order cue using the information provided by the later-encountered morphosyntactic cue BEI. Thus, deficits in executive function, in particular inhibitory control, would lead to misinterpretations of the BEI-constructions. This is exactly what we found in Experiment 1. In addition, as shown in Experiment 2, once no inhibition processes were involved, children with HFA became as good as TD children in interpreting the constructions. The findings of the two experiments are consistent with this executive function deficit account. In other words, their overreliance on the word order cue and their difficulties with reanalysis might reflect their inability to inhibit the initial interpretation led by the word order cue when later encountering the morphosyntactic cue. The findings also have important implications for understanding the nature of the sentence processing mechanism in children with autism. Their problems with the BEI-constructions might reflect a propensity to incrementally assign thematic roles to NPs in a sentence, coupled with a subsequent failure to revise their initial interpretation. More specifically, children with autism might use the incoming linguistic cues incrementally to compute the meaning of a spoken sentence, i.e., assigning provisional semantic analysis. However, sometimes the provisional analysis might turn out to be incorrect, as indicated by later-encountered linguistic cues, thus resulting in a processing difficulty. In the present studies (Experiment 1), when hearing a BEI-construction, the children with autism might use the first-encountered word order cue to assign the agent role to the first NP, but this provisional interpretation turned out to be incorrect, as evidenced by the laterencountered morphosyntactic cue BEI. In order to correctly interpret the first NP as the patient, they needed to inhibit the incorrect provisional analysis. However, most of the time they failed to do so, due to their deficits in executive function, and thus exhibiting misinterpretations of the BEI-constructions. The findings indicate an incremental nature of the sentence

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processing mechanism of children with autism. Previous research has shown that that TD children also incrementally compute the meaning of a spoken sentence using both morphological and syntactic cues (Choi and Trueswell 2010; Huang et  al. 2013; Lew-Williams and Fernald 2007; Omaki 2010; Sekerina and Trueswell 2012; Trueswell et  al. 1999; Van Heugten and Shi 2009; Zhou et  al. 2014). The current findings in conjunction with the previous research suggest that children with HFA do not differ from the TD children in the nature of their sentence processing mechanism. Both groups have an incremental sentence processing mechanism (i.e., When hearing a sentence, children with HFA, like their TD peers, incrementally compute the structural representation and possible meanings of the sentence while drawing on different sources of linguistic information). However, the two groups differ in their abilities to integrate the upcoming information into a previously built representation. Children with HFA are not able to integrate the upcoming information as effectively as TD children to arrive at the intended interpretation, especially when the later-encountered information is inconsistent with the previously built representation and thus a revision is needed, as evidenced by the findings of Experiment 1. To conclude, the present studies provide the first investigation of how children with autism use different linguistic cues in sentence comprehension and what are the sources of their impairments in sentence comprehension. The findings show that children with HFA are able to use both word order cues and morphosyntactic cues in sentence comprehension. Their difficulties with the BEI-constructions observed in Experiment 1 are consequences of the incremental nature of their sentence processing mechanism, coupled with their subsequent difficulty with the reanalysis of a previously built representation, which we attribute to their deficits in executive function. Acknowledgments This research was supported by the National Social Science Foundation of China [16BYY076] to the first author and also the ARC Centre of Excellence in Cognition and its Disorders (CE110001021). The authors are grateful to Dr. Joshua John Diehl and three anonymous reviewers for their insightful comments and suggestions on an earlier version of the paper. The authors would also like to thank the children and the teachers at the Rehabilitation and Education Centre for Children with Autism affiliated with the Peking University Sixth Hospital, Beijing, China, for their assistance and support in running the experiments. Author Contributions PZ conceived of the studies, designed and implemented the studies, performed the statistical analysis and the interpretation of the data, and drafted and revised the manuscript; SC participated in interpreting the data and drafting the manuscript; LG and MJ helped to recruit the participants and to interpret the data. Compliance with Ethical Standards Conflict of Interest of interest.

29 Ethical Approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed Consent Informed consent was obtained from all individual participants included in the study.

Appendix 1 Example filler image used in the experiments.

Appendix 2 Target sentences in Experiment 1 (two spoken sentences were recorded for each visual image, one BA-construction and one BEI-construction). (1)

a. b.

(2)

a. b.

Laohu tiger Laohu tiger

Xiaoyang lamb Xiaoyang lamb

BA BA BEI BEI

shizi lion shizi lion

bao-le hold-PERF bao-le hold-PERF

qilai. up qilai. up

BA BA BEI BEI

xiaoniu cow xiaoniu cow

ti-le kick-PERF ti-le kick-PERF

guoqu. away guoqu. away

The authors declare that they have no conflict

13

Author's personal copy 30

(3)

J Autism Dev Disord (2017) 47:17–32

a. b.

(4)

a. b.

(5)

a. b.

(6)

a. b.

Xiaogou dog Xiaogou dog

BA BA BEI BEI

Xiaozhu pig Xiaozhu pig

BA BA BEI BEI

Xiaogou dog Xiaogou dog

Wugui turtle Wugui turtle

BA BA BEI BEI

BA BA BEI BEI

xiaomao cat xiaomao cat

xiaoma horse xiaoma horse

xiongmao panda xiongmao panda

qingwa frog qingwa frog

mo-le pat-PERF mo-le pat-PERF

yixia. gently yixia. gently

tui-le push-PERF tui-le push-PERF

guoqu. away guoqu. away

zhua-le catch-PERF zhua-le catch-PERF

da-le hit-PERF da-le hit-PERF

qilai. up qilai. up

yi-dun. one-CL yi-dun. one-CL

(12)

a.

Xiaozhu pig Xiaozhu pig

b.

a. b.

Yazi duck Yazi duck

BA BA BEI BEI

gongji rooster gongji rooster

qin-le kiss-PERF qin-le kiss-PERF

yixia. gently yixia. gently

a. b.

Xiaoxiong bear Xiaoxiong bear

BA BA BEI BEI

xiaoxiang elephant xiaoxiang elephant

zhuang-le hit-PERF zhuang-le hit-PERF

yixia. gently yixia. gently

(1)

a. b.

Xiongmao panda Xiongmao panda

BA BA BEI BEI

xiaoma horse xiaoma horse

bang-le tie-PERF bang-le tie-PERF

qilai. up qilai. up

(2)

BA BA

shizi lion

bao-le hold-PERF

qilai. up

b.

BEI BEI

shizi lion

bao-le hold-PERF

qilai. up

a.

BA BA BEI BEI

xiaoniu cow xiaoniu cow

ti-le kick-PERF ti-le kick-PERF

guoqu. away guoqu. away

(3)

BA BA BEI BEI

xiaomao cat xiaomao cat

mo-le pat-PERF mo-le pat-PERF

yixia. gently yixia. gently

tui-le push-PERF tui-le push-PERF

guoqu. away guoqu. away

a.

(4)

a.

(5)

a. b.

(10)

a. b.

Xiaoma horse Xiaoma horse

BA BA BEI BEI

xiaoniu cow xiaoniu cow

cai-le step-on-PERF cai-le step-on-PERF

yixia. gently yixia. gently

(6)

a. b.

(11)

a. b.

13

Xiaoyang lamb Xiaoyang lamb

BA BA BEI BEI

xiaozhu pig xiaozhu pig

la-le pull-PERF la-le pull-PERF

qilai. up qilai. up

guoqu. away guoqu. away

a.

b. (9)

tuo-le drag-PERF tuo-le drag-PERF

Target sentences in Experiment 2 (two spoken sentences were recorded for each visual image, one BA-construction and one BEI-construction).

b. (8)

xiaoma horse xiaoma horse

Appendix 3

b. (7)

BA BA BEI BEI

(7)

a.

BA BA BEI BEI

BA BA BEI BEI

xiaoma horse xiaoma horse

xiongmao panda xiongmao panda

zhua-le catch-PERF zhua-le catch-PERF

qilai. up qilai. up

BA BA BEI BEI

qingwa frog qingwa frog

da-le hit-PERF da-le hit-PERF

yi-dun. one-CL yi-dun. one-CL

BA BA

gongji rooster

qin-le kiss-PERF

yixia. gently

Author's personal copy J Autism Dev Disord (2017) 47:17–32 b.

(8)

a. b.

(9)

a. b.

(10)

(11)

BA BA BEI BEI

BA BA BEI BEI

gongji rooster

qin-le kiss-PERF

yixia. gently

xiaoxiang elephant xiaoxiang elephant

zhuang-le hit-PERF zhuang-le hit-PERF

yixia. gently yixia. gently

xiaoma horse xiaoma horse

bang-le tie-PERF bang-le tie-PERF

qilai. up qilai. up

a.

BA

xiaoniu

cai-le

yixia.

b.

BA BEI BEI

cow xiaoniu cow

step-on-PERF cai-le step-on-PERF

gently yixia. gently

la-le pull-PERF la-le pull-PERF

qilai. up qilai. up

a. b.

(12)

BEI BEI

31

a. b.

BA BA BEI BEI

BA BA BEI BEI

xiaozhu pig xiaozhu pig

xiaoma horse xiaoma horse

tuo-le drag-PERF tuo-le drag-PERF

guoqu. away guoqu. away

References American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders, 4th edition, text revision (DSM-IVTR). Washington, DC: American Psychiatric Association. Bennetto, L., Pennington, B. F., & Rogers, S. J. (1996). Intact and impaired memory functions in autism. Child Development, 67, 1816–1835. Boucher, J. (2012). Research review: Structural language in autism spectrum disorder–characteristics and causes. Journal of Child Psychology and Psychiatry, 53, 219–233. Choi, Y., & Trueswell, J. C. (2010). Children’s (in) ability to recover from garden paths in a verb-final language: Evidence for developing control in sentence processing. Journal of Experimental Child Psychology, 106, 41–61. Christ, S. E., Holt, D. D., White, D. A., & Green, L. (2007). Inhibitory control in children with autism spectrum disorder. Journal of Autism and Developmental Disorders, 37, 1155–1165. Corrigan, R. (1988). Who dun it? The influence of actor-patient animacy and type of verb in the making of causal attributions. Journal of Memory and Language, 27, 447–465.

de Villiers, J. G., & de Villiers, P. A. (1973). Development of the use of word order in comprehension. Journal of Psycholinguistic Research, 2, 331–341. Dempster, F. N. (1992). The rise and fall of the inhibitory mechanism: Toward a unified theory of cognitive development and aging. Developmental Review, 12, 45–75. Eigsti, I. M., Bennetto, L., & Dadlani, M. B. (2007). Beyond pragmatics: Morphosyntactic development in autism. Journal of Autism and Developmental Disorders, 37, 1007–1023. Eigsti, I. M., de Marchena, A. B., Schuh, J. M., & Kelley, E. (2011). Language acquisition in autism spectrum disorders: A developmental review. Research in Autism Spectrum Disorders, 5, 681–691. Gavarró, A., & Heshmati, Y. (2014). An investigation on the comprehension of Persian passives in typical development and autism. Catalan journal of linguistics, 13, 79–98. Gong, Y. X., & Dai, X. Y. (1992). Chinese-Wechsler Young Children Scale of Intelligence (C-WYCSI). Changsha, Hunan: Map Press. Hill, E. L. (2004). Executive dysfunction in autism. Trends in Cognitive Sciences, 8, 26–32. Howlin, P. (2003). Outcome in high-functioning adults with autism with and without early language delays: Implications for the differentiation between autism and Asperger syndrome. Journal of Autism and Developmental Disorders, 33, 3–13. Huang, Y.-T., Zheng, X., Meng, X., & Snedeker, J. (2013). Children’s assignment of grammatical roles in the online processing of Mandarin passive sentences. Journal of Memory and Language, 69, 589–606. Hudry, K., Leadbitter, K., Temple, K., Slonims, V., McConachie, H., Aldred, C., & Charman, T. (2010). Preschoolers with autism show greater impairment in receptive compared with expressive language abilities. International Journal of Language & Communication Disorders, 45, 681–690. Hughes, C., Russell, J., & Robbins, T. W. (1994). Evidence for executive dysfunction in autism. Neuropsychologia, 32, 477–492. Joseph, R. M., McGrath, L. M., & Tager-Flusberg, H. (2005). Executive dysfunction and its relation to language ability in verbal school-age children with autism. Developmental Neuropsychology, 27, 361–378. Koning, C., & Magill-Evans, J. (2001). Social and language skills in adolescent boys with Asperger syndrome. Autism: The International Journal of Research and Practice, 5, 23–36. Kover, S. T., Haebig, E., Oakes, A., McDuffie, A., Hagerman, R. J., & Abbeduto, L. (2014). Sentence comprehension in boys with autism spectrum disorder. American Journal of Speech-Language Pathology, 23, 385–394. Lew-Williams, C., & Fernald, A. (2007). Young children learning Spanish make rapid use of grammatical gender in spoken word recognition. Psychological Science, 33, 193–198. Li, C., & Thompson, S. (1981). Mandarin Chinese: A functional reference grammar. Berkeley: University of California Press. Li, P. (1990). Aspect and aktionsart in child Mandarin. Ph.D. dissertation, Leiden University. Li, P., Bates, E., Liu, H., & MacWhinney, B. (1992). Cues as functional constraints on sentence processing in Chinese. In H. C. Chen & O. Tzeng (Eds.), Language processing in Chinese. Series of Advances in Psychology (pp. 207–234). North-Holland: Elsevier Science Publisher. Lord, C., Rutter, M., DiLavore, P. C., & Risi, S. (1999). Autism diagnostic observation schedule. Los Angeles, CA: Western Psychological Services. Luna, B., Doll, S. K., Hegedus, S. J., Minshew, N. J., & Sweeney, J. A. (2007). Maturation of executive function in autism. Biological Psychiatry, 61, 474–481.

13

Author's personal copy 32 Naigles, L. R. (1996). The use of multiple frames in verb learning via syntactic bootstrapping. Cognition, 58, 221–251. Novick, J. M., Trueswell, J. C., & Thompson-Schill, S. L. (2005). Cognitive control and parsing: Reexamining the role of Broca’s area in sentence comprehension. Cognitive, Affective, & Behavioral Neuroscience, 5, 263–281. Omaki, A. (2010). Commitment and flexibility in the developing parser. Ph.D. dissertation, University of Maryland. Ozonoff, S., Pennington, B. F., & Rogers, S. J. (1991). Executive function deficits in high-functioning autistic individuals: Relationship to theory of mind. Journal of Child Psychology and Psychiatry, 32, 1081–1105. Paul, R., Fischer, M. L., & Cohen, D. J. (1988). Sentence comprehension strategies in children with autism and specific language disorders. Journal of Autism and Developmental Disorders, 18, 669–679. Perovic, A., Modyanova, N., & Wexler, K. (2007). Knowledge of c-command and A-movement in children and adolescents with autism and with Asperger syndrome. Paper presented at the Generative Approaches to Language Acquisition (GALA 2007), Barcelona, Spain. Perovic, A., Modyanova, N., & Wexler, K. (2013). Comprehension of reflexive and personal pronouns in children with autism: A syntactic or pragmatic deficit? Applied Psycholinguistics, 34, 813–835. Rapin, I., & Dunn, M. (2003). Update on the language disorders of individuals on the autistic spectrum. Brain Development, 25, 166–172. Riches, N. G., Loucas, T., Baird, G., Charman, T., & Simonoff, E. (2012). Interpretation of compound nouns by adolescents with specific language impairment and autism spectrum disorders: An investigation of phenotypic overlap. International Journal of Speech-Language Pathology, 14, 307–317. Saalasti, S., Lepistö, T., Toppila, E., Kujala, T., Laakso, M., Nieminen-von Wendt, T., & Jansson-Verkasalo, E. (2008). Language abilities of children with Asperger syndrome. Journal of Autism and Developmental Disorders, 38, 1574–1580. Sekerina, I. A., & Trueswell, J. C. (2012). Interactive processing of contrastive expressions by Russian children. First Language, 32, 63–87. Seung, H. K. (2007). Linguistic characteristics of individuals with high functioning autism and Asperger syndrome. Clinical Linguistics and Phonetics, 21, 247–259. Sinclair, H., & Bronckart, J. P. (1972). SVO A linguistic universal? A study in developmental psycholinguistics. Journal of Experimental Child Psychology, 14, 329–348. Slobin, D. I. (1973). Cognitive prerequisites for the development of grammar. Studies of Child Language Development, 1, 75–208. Stockbridge, M. D., Happé, F. G., & White, S. J. (2014). Impaired comprehension of alternating syntactic constructions in autism. Autism Research, 7, 314–321.

13

J Autism Dev Disord (2017) 47:17–32 Su, Y. E., & Su, L. Y. (2015). Interpretation of logical words in Mandarin-speaking children with autism spectrum disorders: Uncovering knowledge of semantics and pragmatics. Journal of Autism and Developmental Disorders, 45, 1938–1950. Su, Y. E., Jin, Y., Wan, G. B., Zhang, J. S., & Su, L. Y. (2014). Interpretation of wh-words in Mandarin-speaking high-functioning children with autism spectrum disorders. Research in Autism Spectrum Disorders, 8, 1364–1372. Sun, C. F., & Givón, T. (1985). On the so-called SOV word order in Mandarin Chinese: A quantified text study and its implications. Language, 61, 329–351. Tager-Flusberg, H. (1981). Sentence comprehension in autistic children. Applied Psycholinguistics, 2, 5–24. Tager-Flusberg, H., Paul, R., & Lord, C. (2005). Language and communication in autism. In F. R. Volkmar, R. Paul, A. Klin & D. Cohen (Eds.), Handbook of autism and pervasive developmental disorders (3rd  edn., pp.  335–364). Hoboken, NJ: Wiley. Terzi, A., Marinis, T., Kotsopoulou, A., & Francis, K. (2014). Grammatical abilities of Greek-speaking children with autism. Language Acquisition, 21, 4–44. Trueswell, J. C., Sekerina, I., Hill, N. M., & Logrip, M. L. (1999). The kindergarten-path effect: Studying on-line sentence processing in young children. Cognition, 73, 89–134. Van Heugten, M., & Shi, R. (2009). French-learning toddlers use gender information on determiners during word recognition. Developmental Science, 12, 419–425. Wang, Q., Lillo-Martin, D., Best, C. T., & Levitt, A. (1992). Null subject versus null object: Some evidence from the acquisition of Chinese and English. Language acquisition, 2, 221–254. Welsh, M. C., Pennington, B. F., & Groisser, D. B. (1991). A normative-developmental study of executive function: A window on prefrontal function in children. Developmental Neuropsychology, 7, 131–149. Williams, D. L., Goldstein, G., Carpenter, P. A., & Minshew, N. J. (2005). Verbal and spatial working memory in autism. Journal of Autism and Developmental Disorders, 35, 747–756. Zelazo, P. D., Carter, A., Reznick, J. S., & Frye, D. (1997). Early development of executive function: A problem-solving framework. Review of general psychology, 1, 1–29. Zhou, P., Crain, S., Gao, L., Tang, Y., & Jia, M. (2015). The use of grammatical morphemes by Mandarin-speaking children with high functioning autism. Journal of Autism and Developmental Disorders, 45, 1428–1436. Zhou, P., Crain, S., & Zhan, L. (2014). Grammatical aspect and event recognition in children’s online sentence comprehension. Cognition, 133, 262–276.