Auditory Processing Skills and Joint Attention Abilities in Children with ASDs

Background: A number of studies demonstrated that almost 30% of children with Autism Spectrum Disorders (ASDs) are affected by Auditory Processing Disorders (Baranek, Foster & Berkson, 1997), which reduce their ability to attend, understand and remember information from verbal language. Although a number of recent studies highlighted the importance of auditory processing skills for language development in children with ASDs (Dawson & Wathing, 2000; Tager-Flusberg & Joseph, 2003; Khul, Coffey-Corina, Padden, Dawson, 2005), the relationship between Auditory Process Disorders and Joint Attention abilities, who are known to be an important precursor to language acquisition, has been rarely explored in children with ASDs. Objectives: This study evaluates Joint Attention (JA) abilities in children with ASDs, measured by the means of an Eye Tracking paradigm, in relation to their auditory processing skills. Methods: 35 children with ASDs (6 females), 31 with a diagnosis of Autism and 4 of PDD-NOS, aged between 46-137 months (mean age=88.37 months; SD=26), mean non-verbal level measured with the Leiter-R=77.03 (SD=18.43), participated in the study. 37 typically developing children (18 females), ranging in age from 39 to 79 months (mean age=51.76 months, SD=4.42) were included as controls. Auditory processing abilities were evaluated with a list of non-words (Cornoldi, Miato, Molin e Poli, 2009) and children with ASDs were divided into two groups, using the mean of the group of ASDs children as cut-off: a group with lower auditory processing skills (below the mean) and a group with average auditory processing skills (equal or above the mean). To evaluate JA abilities, the children were shown a video of a brief social interaction between two characters, by the means of a Tobii T60 Eye Tracker. The number of JA visual pattern (character A – object - character B) produced by participants when they visually explored the social scene were counted. Results: 58% of the children with ASDs showed average auditory processing (mean number of correct non-words=51; sd=4.811) while 42% of them scored lower in auditory processing skills (mean number of correct non-words=37; ds=5.02). A between group ANOVA showed that the children with lower auditory processing skills produced a significantly lower number of JA visual patterns compared to the children with ASDs with average auditory processing abilities and to the TD controls (F=8.094; df=2;71; p=0.01). The two subgroups of children with ASDs did not differ for verbal and non-verbal abilities, as measured respectively by the Peabody Picture Vocabulary Test and by the Leiter-R. Conclusions: These results seems to support the hypothesis of a relationship between social and linguistic processing in children with ASDs. Moreover, they highlight the importance of assessing auditory processing skills in these children, since difficulties in perceiving and segmenting linguistic information, together with a lack of JA abilities can result in a significant disadvantage in language learning.