Sensory-Motor Features of Infants with and without Risk Factors for Autism

Background:

Identification of early signs of autism is a priority for the field as it provides therapeutic targets for early intervention. As it is difficult to detect clinically meaningful variation in language, social and cognitive development in very young children, sensory-motor differences may offer a better means of evaluating autism risk in the first year of life. Children with autism demonstrate sensory-motor difficulties that are associated with the core deficits in autism. Variations in sensory-motor performance are reliably observed during infancy.

Objectives:

The purpose of this study was to characterize sensory-motor features of infants in their first year of life with and without risk factors for autism. 

Methods:

Standardized video footage and early autism screening test scores from 39 infants was used. Participants included a high-risk infant group (SIB-ASD) comprising of 24 infants with a sibling or close relative diagnosed with an ASD.  A second group consisted of 15 infants with no known family history of ASD (NO-ASD). 

Infants were videotaped while being assessed using early autism screening tools and developmental evaluations at ages 2, 4 and 6 months. Videotapes at each time point were coded using an observation protocol of sensory-motor features. Blinded researchers identified head lag, symmetrical posture, grasp and release, midline, mouthing, response to touch, and scored motor development using the AIMS (Alberta Scale of Infant Development).

Results:

Preliminary data analysis has been conducted on grasp and release behaviors and AIMS scores for 2 and 4 month old participants (n=22). Preliminary results are as follows:

•  NO-ASD (n=10) participants spent more time with their hands in the midline (mean proportion of total time observed = 6%, SD=12%) than SIB-ASD (n=12) participants (mean proportion = 0.6%, SD=1%) with a trend for the NO-ASD group having more midline behaviors (p=0.10).
•   NO-ASD participants were slightly more successful in retrieving objects presented to them (mean rate of retrieval = 0.16, SD=0.12) than SIB-ASD (mean retrieval rate = 0.12, SD=0.11) but the difference is not statistically significant (p=0.42).
• There were no differences in AIMS scores at 2 months of age.  
• At 4 months, NO-ASD participants had higher AIMS scores (mean = 11.73, SD 2.7) than SIB-ASD (mean 10.73, SD 2.28) with a trend for the NO-ASD group having better motor skills (p=0.10).

 Conclusions:

Two month old infants with and without risk factors for autism demonstrate high variability in sensory-motor skills. A trend for decreased midline behavior at 2 months was observed for infants with risk factors for autism. Further, 4 month old infants with risk factors for autism performed less well on the AIMS. These trends will be examined further at the 6-month time point alongside results from early autism screening assessments and reported in the full paper.