Retrospective Video Analysis of Grasp Types and Functional Actions in Infants at Heightened Risk for Autism Spectrum Disorders
Objectives: To analyze functional grasps and functional actions with a standard object in a group of infants at heightened risk for ASD.
Methods: Participants were 42 infants at heightened risk for ASD: 15 with typical development (TD), 15 with language delay (LD) and 12 with ASD (ASD). As part of a larger longitudinal study, infants were videotaped at home for 45 min sessions at 10, 12, 18 and 24 months of age and administered the Early Social Communication Scales (ESCS; Mundy et al., 2003). During the ESCS, infants sat at a table and were given the opportunity to grasp and use a spoon positioned in front of them together with a small bowl for 1 min. Spontaneous behavior was retrospectively video coded analyzing: (1) whether infants produced at least one spoon grasp (grasp production); (2) in all cases in which the spoon was grasped at least once, whether the first grasp produced was functional or non-fuctional (grasp types); (3) in all cases in which at least one spoon grasp was produced, the number of infants that produced a functional action. Grasps were classified as ‘functional’ if they allowed to easily perform an eating action and ‘non-functional’ if the grasp rendered eating actions difficult (Connolly & Dalgleish, 1989). Actions were classified as ‘functional’ if the spoon was either dipped in the bowl or placed in the bowl and brought to the mouth as in feeding. Analyses focused on group differences in grasp production, grasp types, and numbers of infants producing a functional action.
Results: Analyses indicated: (1) no differences in numbers of infants who grasped the spoon (all ps >.05); (2) a significant difference at 24 months in the number of functional vs. non-functional grasps between ASD and TD (p=.03), but not between TD and LD infants (p=.10); (3) a significant difference at 10 months in the numbers of infants producing a functional action between ASD and TD (p=.005), but not between TD and LD infants (p=.23). This difference was no longer present by 18 months.
Conclusions: Data indicate later onset of functional grasps and actions in infants subsequently diagnosed with ASD. None of the infants in the ASD group produced a functional action at 10 months. Late onset of functional grasps and actions may hinder their role in supporting infant-caregiver interactions, leading to cascading effects on later communication skills in ASD.