Differences in Reaching and Object Exploration Skills Between Infants At Risk for Autism and Typically Developing Infants in the First 15 Months of Life

Background:  

Infants begin to grasp objects at around 6 months of age and continue to explore various object properties based on shape, size, and texture. These fine motor skills lay a foundation for cognitive skills such as object knowledge as well as social communication skills such as hand gestures. Infants at risk for autism (AU sibs) also present with fine motor delays (Landa et al., 2005) which may in turn affect their object exploration skills.

Objectives:  

In the present study, we examined the differences in object exploration skills between AU sibs and typically developing (TD) infants and correlated them to infants’ future social and motor outcomes. In addition, we examined how caregiver feedback influences object exploration skills (Bourgeois et al., 2005) in AU sibs and TD infants.

Methods:  

12 TD infants and 12 AU sibs were observed at 6, 9, 12, and 15 months of age with developmental follow-up and autism screening conducted at 18 and 24 months. Infants were seated upright in a booster seat and were offered three different objects – a long rattle, a circular solid rattle, and a circular soft koosh ball. In the spontaneous conditions, infants were allowed to spontaneously explore each object. In the social conditions, an adult tester showed the infant the property of each object (i.e.; vertical shaking of the long rattle, horizontal shaking of the solid ball, and fingering of the koosh ball) and additional opportunities for object exploration were provided. Videotaped data will be coded for percent duration of oral, visual, and haptic exploration. Rates of demonstrated actions and task-appropriate grasping patterns, for example, power or pincer grips, one-handed vs. two-handed grasps, and rates of transfers will also be coded.

Results:  

Our preliminary analyses suggest that AU sibs will show increased visual exploration, reduced grasping and bimanual use, and fewer appropriate motor responses to caregiver-provided demonstrations as compared to TD infants. In addition, AU sibs with poor social outcomes at 18 or 24 months will show greater fine motor impairments and poor use of caregiver feedback during object exploration as compared to the AU sibs with typical outcomes.

Conclusions:

TD infants demonstrated increased fine motor control and increased ability to shape their actions based on caregiver feedback across 6 to 15 months of age. In contrast, AU sibs’ impairments in fine motor control and lack of social attention may have contributed to their poor object exploration skills. Overall, spontaneous versus social conditions of object exploration may be an effective context to assess the atypical fine motor and visual attention patterns of infants at risk for autism and may provide a window for early diagnosis of future autism-related motor and social impairments.