In this review, we summarize studies investigating comprehension of three core grammatical structures (Subject-Verb-Object word order, grammatical aspect and wh-questions) in diverse samples of Mandarin-acquiring preschoolers with ASD, all utilizing the Intermodal Preferential Looking (IPL) paradigm. Results showed that children with ASD, though they were delayed in chronological age and expressive language (including significantly lower vocabulary production scores), acquired various grammatical constructions similarly to their typically developing peers. Moreover, Mandarin-acquiring preschoolers with ASD demonstrated similar acquisition patterns of these three core grammatical structures, as has been reported in previous IPL studies among English-acquiring children with ASD (Naigles & Fein, 2017). Thus, the results testify that universal underlying mechanisms are playing vital roles in grammatical acquisition of children with ASD across languages (e.g., the setting of word order parameters, the preservation of functional morphemes, the universal operation of WH-Movement), despite their pervasive social cognition impairments. These findings suggest that core grammatical knowledge may be preserved in children with ASD, even in the face of radical differences in language environment and social/communicative deficits, supporting the contribution of the language faculty in autistic language acquisition. The results shed light on the sharp contrast between linguistic competence (governed by the internal computational system of the language faculty) vs. linguistic performance (affected by loci of impairment in the sensory-motor and the conceptual-intentional interfaces) in ASD. Furthermore, the results highlight the dissociation between the lexical vs. the grammatical modules in ASD, supporting a modular view of the diverse language domains in the language faculty.
