Impact Reduces Social Hyporesponsiveness and Translates to More Optimal Spoken Language Outcomes Infants at Heightened Risk for Autism

Background: Infant siblings of children affected by autism spectrum disorder (Sibs-ASD) are at high risk of receiving a future diagnosis of ASD or language delay and may show hyporesponsiveness (i.e., reduced or absent responding to sensory stimuli), in particular to social stimuli, such as a name call, tap on the shoulder, or wave. It has been proposed that such social hyporesponsiveness, especially early in life, may produce cascading effects on the development of higher-level skills, such as spoken language. In an early intervention called ImPACT, parents are taught to use a number of strategies that might reduce social hyporesponsivity (e.g., well-timed animation, face to face positioning, behavioral responsivity) and support language acquisition (e.g., language responsivity, communication temptations, direct communication teaching) in Sibs-ASD.

Objectives: The present study sought to evaluate whether an early intervention called ImPACT may reduce social hyporesponsiveness and translate to more optimal spoken language outcomes in Sibs-ASD.

Methods: At entry to the study (T1), 39 infants (17 male, 22 female; chronological ages 12-18 months) were randomly assigned to receive ImPACT vs a business as usual (BAU) control at Vanderbilt University. Families assigned to ImPACT received 24 sessions of parent training over 3 months by an ImPACT-certified speech-language pathologist (SLP) or someone trained and supervised by the certified SLP in the home setting. Social hyporesponsiveness was measured at immediate post-treatment (3 months post study entry; T2) with the Sensory Experiences Questionnaire. Infants’ spoken language was measured at the final follow-up period (9 months post study entry; T3) using the average of z-scores for the (a) raw number of words infants were reported to say on the MacArthur-Bates Communicative Development Inventories (MBCDI), (b) Mullen Scales of Early Learning expressive language age equivalency, and (c) number of different words spoken in the context of Communication and Symbolic Behavior Scales: Developmental Profile and Brief Observation of Social Communication Change samples. Assessors and coders were blind to treatment assignment. T2 social hyporesponsiveness and T3 MBCDI expressive raw scores were log 10 and square root transformed, respectively, to correct for positive skew.

Results: ImPACT was superior to BAU for effects on T2 social hyporesponsiveness for infants with parents who entered treatment with more formal education (p value for parent formal education * treatment group parameter in regression model testing moderated effect = .0015). The effect of ImPACT on social hyporesponsiveness translated to more optimal T3 spoken language outcomes for this subgroup of infants, 95% CI for conditional indirect effect of treatment on spoken language outcomes via midpoint social hyporesponsiveness according to parent formal education [.0001, .7774].

Conclusions: This study is the first to our knowledge to demonstrate that an early “preventative” intervention may impact social hyporesponsiveness in infants who are at heightened risk for autism. Results suggest ImPACT has the greatest potential to reduce social hyporesponsiveness and translate to more optimal language outcomes when parents have a relatively high level of formal education and perhaps are best positioned to learn strategies to be applied in the course of everyday interactions with their infant.

Background:

Infant siblings of children affected by autism spectrum disorder (Sibs-ASD) are at high risk of receiving a future diagnosis of ASD or language delay and may show hyporesponsiveness (i.e., reduced or absent responding to sensory stimuli), in particular to social stimuli, such as a name call, tap on the shoulder, or wave. It has been proposed that such social hyporesponsiveness, especially early in life, may produce cascading effects on the development of higher-level skills, such as spoken language. In an early intervention called ImPACT, parents are taught to use a number of strategies that might reduce social hyporesponsiveness (e.g., well-timed animation, face to face positioning, behavioral responsivity) and support language acquisition (e.g., language responsivity, communication temptations, direct communication teaching) in Sibs-ASD.

Objectives:

The present study sought to evaluate whether ImPACT may reduce social hyporesponsiveness and translate to more optimal spoken language outcomes in Sibs-ASD.

Methods:

At entry to the study (T1), 39 infants (17 male, 22 female; chronological ages 12-18 months) were randomly assigned to receive ImPACT vs a business as usual (BAU) control at Vanderbilt University. Families assigned to ImPACT received 24 sessions of parent training over 3 months by an ImPACT-certified speech-language pathologist (SLP) or someone trained and supervised by the certified SLP in the home setting. Social hyporesponsiveness was measured at immediate post-treatment (3 months post study entry; T2) with the Sensory Experiences Questionnaire. Infants’ spoken language was measured at the final follow-up period (9 months post study entry; T3) using the average of z-scores for the (a) raw number of words infants were reported to say on the MacArthur-Bates Communicative Development Inventories (MBCDI), (b) Mullen Scales of Early Learning expressive language age equivalency, and (c) number of different words spoken in the context of Communication and Symbolic Behavior Scales: Developmental Profile and Brief Observation of Social Communication Change samples. Assessors and coders were blind to treatment assignment. T2 social hyporesponsiveness and T3 MBCDI expressive raw scores were log 10 and square root transformed, respectively, to correct for positive skew.

Results:

ImPACT was superior to BAU for effects on T2 social hyporesponsiveness for infants with parents who entered treatment with more formal education (p value for parent formal education * treatment group parameter in regression model testing moderated effect = .0015). The effect of ImPACT on social hyporesponsiveness translated to more optimal T3 spoken language outcomes for this subgroup of infants, 95% CI for conditional indirect effect of treatment on spoken language outcomes via midpoint social hyporesponsiveness according to parent formal education [.0001, .7774].

Conclusions:

This study is the first to our knowledge to demonstrate that an early “preventative” intervention may impact social hyporesponsiveness in infants who are at heightened risk for autism. Results suggest ImPACT has the greatest potential to reduce social hyporesponsiveness and translate to more optimal language outcomes when parents have a relatively high level of formal education and perhaps are best positioned to learn strategies to be applied in the course of everyday interactions with their infant.