The Online Processing of Hypothetical Events.

A conditional statement If P then Q is formed by combining the two propositions P and Q together with the conditional connective If ··· then ···. When embedded under the conditional connective, the two propositions P and Q describe hypothetical events that are not actualized. It remains unclear when such hypothetical thinking is activated in the real-time comprehension of conditional statements. To tackle this problem, we conducted an eye-tracking experiment using the visual world paradigm. Participants' eye movements on the concurrent image were recorded when they were listening to the auditorily presented conditional statements. Depending on when and what critical information is added into the auditory input, there are four possible temporal slots to observe in the online processing of the conditional statement: the sentential connective If, the antecedent P, the consequent Q, and the processing of the sentence following the conditional. We mainly focused on the first three slots. First, the occurrence of the conditional connective should trigger participants to search in the visual world for the event that could not assign a truth-value to the embedded proposition. Second, if the embedded proposition P can be determined as true by an event, the hypothetical property implied by the connective would prevent the participants from excluding the consideration of other events. The consideration of other events would yield more fixations on the events where the proposition is false.

Understanding Others' Minds: Social Inference in Preschool Children with Autism Spectrum Disorder.

The study used an eye-tracking task to investigate whether preschool children with autism spectrum disorder (ASD) are able to make inferences about others' behavior in terms of their mental states in a social setting. Fifty typically developing (TD) 4- and 5-year-olds and 22 5-year-olds with ASD participated in the study, where their eye-movements were recorded as automatic responses to given situations. The results show that unlike their TD peers, children with ASD failed to exhibit eye gaze patterns that reflect their ability to infer about others' behavior by spontaneously encoding socially relevant information and attributing mental states to others. Implications of the findings were discussed in relation to the proposal that implicit/spontaneous Theory of Mind is persistently impaired in ASD.

Predictive Language Processing in Preschool Children with Autism Spectrum Disorder: An Eye-Tracking Study.

Sentence comprehension relies on the abilities to rapidly integrate different types of linguistic and non-linguistic information. The present study investigated whether Mandarin-speaking preschool children with autism spectrum disorder (ASD) are able to use verb information predictively to anticipate the upcoming linguistic input during real-time sentence comprehension. 26 five-year-olds with ASD, 25 typically developing (TD) five-year-olds and 24 TD four-year-olds were tested using the visual world eye-tracking paradigm. The results showed that the 5-year-olds with ASD, like their TD peers, exhibited verb-based anticipatory eye movements during real-time sentence comprehension. No difference was observed between the ASD and TD groups in the time course of their eye gaze patterns, indicating that Mandarin-speaking preschool children with ASD are able to use verb information as effectively and rapidly as TD peers to predict the upcoming linguistic input.

Using the Visual World Paradigm to Study Sentence Comprehension in Mandarin-Speaking Children with Autism.

Sentence comprehension relies on the ability to rapidly integrate different types of linguistic and non-linguistic information. However, there is currently a paucity of research exploring how preschool children with autism understand sentences using different types of cues. The mechanisms underlying sentence comprehension remains largely unclear. The present study presents a protocol to examine the sentence comprehension abilities of preschool children with autism. More specifically, a visual world paradigm of eye-tracking is used to explore the moment-to-moment sentence comprehension in the children. The paradigm has multiple advantages. First, it is sensitive to the time course of sentence comprehension and thus can provide rich information about how sentence comprehension unfolds over time. Second, it requires minimal task and communication demands, so it is ideal for testing children with autism. To further minimize the computational burden of children, the present study measures eye movements that arise as automatic responses to linguistic input rather than measuring eye movements that accompany conscious responses to spoken instructions.

Using Eye Movements Recorded in the Visual World Paradigm to Explore the Online Processing of Spoken Language.

In a typical eye tracking study using the visual world paradigm, participants' eye movements to objects or pictures in the visual workspace are recorded via an eye tracker as the participant produces or comprehends a spoken language describing the concurrent visual world. This paradigm has high versatility, as it can be used in a wide range of populations, including those who cannot read and/or who cannot overtly give their behavioral responses, such as preliterate children, elderly adults, and patients. More importantly, the paradigm is extremely sensitive to fine grained manipulations of the speech signal, and it can be used to study the online processing of most topics in language comprehension at multiple levels, such as the fine grained acoustic phonetic features, the properties of words, and the linguistic structures. The protocol described in this article illustrates how a typical visual world eye tracking study is conducted, with an example showing how the online processing of some semantically complex statements can be explored with the visual world paradigm.

Scalar and Ignorance Inferences Are Both Computed Immediately upon Encountering the Sentential Connective: The Online Processing of Sentences with Disjunction Using the Visual World Paradigm.

Accounts based on the pragmatic maxim of quantity make different predictions about the computation of scalar versus ignorance inferences. These different predictions are evaluated in two eye-tracking experiments using a visual world paradigm to assess the on-line computation of inferences. The test sentences contained disjunction phrases, which engender both kinds of inferences. The first experiment documented that both inferences are computed immediately upon encountering the disjunctive connective, at nearly identical temporal locations. The second experiment was designed to determine whether or not there exists an intermediate stage at which the truth of the corresponding conjunction phrase is ignored. No such stage was found.

Children's on-line processing of epistemic modals.

In this paper we investigated the real-time processing of epistemic modals in five-year-olds. In a simple reasoning scenario, we monitored children's eye-movements while processing a sentence with modal expressions of different force (might/must). Children were also asked to judge the truth-value of the target sentences at the end of the reasoning task. Consistent with previous findings (Noveck, 2001), we found that children's behavioural responses were much less accurate compared to adults. Their eye-movements, however, revealed that children did not treat the two modal expressions alike. As soon as a modal expression was presented, children and adults showed a similar fixation pattern that varied as a function of the modal expression they heard. It is only at the very end of the sentence that children's fixations diverged from the adult ones. We discuss these findings in relation to the proposal that children narrow down the set of possible outcomes in undetermined reasoning scenarios and endorse only one possibility among several (Acredolo & Horobin, 1987, Ozturk & Papafragou, 2015).

Grammatical aspect and event recognition in children's online sentence comprehension.

This study investigated whether or not the temporal information encoded in aspectual morphemes can be used immediately by young children to facilitate event recognition during online sentence comprehension. We focused on the contrast between two grammatical aspectual morphemes in Mandarin Chinese, the perfective morpheme -le and the (imperfective) durative morpheme -zhe. The perfective morpheme -le is often used to indicate that an event has been completed, whereas the durative morpheme -zhe indicates that an event is still in progress or continuing. We were interested to see whether young children are able to use the temporal reference encoded in the two aspectual morphemes (i.e., completed versus ongoing) as rapidly as adults to facilitate event recognition during online sentence comprehension. Using the visual world eye-tracking paradigm, we tested 34 Mandarin-speaking adults and 99 Mandarin-speaking children (35 three-year-olds, 32 four-year-olds and 32 five-year-olds). On each trial, participants were presented with spoken sentences containing either of the two aspectual morphemes while viewing a visual image containing two pictures, one representing a completed event and one representing an ongoing event. Participants' eye movements were recorded from the onset of the spoken sentences. The results show that both the adults and the three age groups of children exhibited a facilitatory effect trigged by the aspectual morpheme: hearing the perfective morpheme -le triggered more eye movements to the completed event area, whereas hearing the durative morpheme -zhe triggered more eye movements to the ongoing event area. This effect occurred immediately after the onset of the aspectual morpheme, both for the adults and the three groups of children. This is evidence that young children are able to use the temporal information encoded in aspectual morphemes as rapidly as adults to facilitate event recognition. Children's eye movement patterns reflect a rapid mapping of grammatical aspect onto the temporal structures of events depicted in the visual scene.

Children's use of phonological information in ambiguity resolution: a view from Mandarin Chinese.

How do children develop the mapping between prosody and other levels of linguistic knowledge? This question has received considerable attention in child language research. In the present study two experiments were conducted to investigate four- to five-year-old Mandarin-speaking children's sensitivity to prosody in ambiguity resolution. Experiment 1 used eye-tracking to assess children's use of stress in resolving structural ambiguities. Experiment 2 took advantage of special properties of Mandarin to investigate whether children can use intonational cues to resolve ambiguities involving speech acts. The results of our experiments show that children's use of prosodic information in ambiguity resolution varies depending on the type of ambiguity involved. Children can use prosodic information more effectively to resolve speech act ambiguities than to resolve structural ambiguities. This finding suggests that the mapping between prosody and semantics/pragmatics in young children is better established than the mapping between prosody and syntax.