Accessing Meaning of Ambigous Homographs Embedded within Sentences in Children with ASD

Background:   Considerable research focus concerning the theories of Weak Central Coherence (WCC) and Executive Functioning (EF) have been directed towards the cognitive atypicalities that may account for verbal comprehension impairments in individuals with ASD. The cause of language comprehension deficits in individuals with ASD is still not fully understood. To date evidence pertaining to individuals with ASD to process information in context remains mixed and has mainly focused on pronunciation tasks

Objectives:   My thesis study investigated how children with ASD can use meaning activation of word primes to disambiguate target homographs inserted in the context of a sentence at automatic (300ms) and controlled (1000ms) stimulus onset asynchronies (SOAs).

Methods:   Ten children with ASD and ten typically developing controls were first matched on chronological age and mental by utilizing the Kauffman Brief Intelligence Test, Second Edition. ASD symptomatology was verified using the Adolescent Autism Quotient and Vineland II Adaptive Behavior Scales. A semantic priming keystroke task was created using Inquisit Priming software. Participants were given 120 prime-homograph word target pairs split into four different conditions. Each trial consisted of the priming task consisted of a word prime(related or unrelated to the homograph), a 300ms or 1000ms delay, followed by a homograph word target embedded within the context of a sentence. Participants judged if the sentence made sense or not by either pressing X(Does not make sense) M(Makes sense) on the keyboard. Reaction time and accuracy of each trial were recorded.

Results:   Children with ASD were as accurate as typically developing children in disambiguating the target homograph in each sentence. Incorrect responses between related and unrelated meaning trials did not differ. The second major finding of this study is that children with ASD were as fast as typically developing children in making a determination as to whether a sentence made sense in both related and unrelated conditions. Additionally, no differences in reaction time were observed between the ASD and typically developing group in conditions involving short or long SOAs.

Conclusions: The most fitting explanation concerning the results of this study is that children with ASD may have a specific language-processing deficit that prevents them from using semantic knowledge in spoken language. The patterns of results from this study show no deficit in verbal comprehension on a priming task that did not require pronunciation. Results run contrary to other studies concerning the accounts of WCC and EF and that may be because the research examining these theories put too much emphasis on pronunciation of a word rather than actual comprehension of the meaning of a word. Overall, children with ASD were able to use contextual information provided by the word primes in order to disambiguate target homographs embedded within the context of a sentence.