Research Article: Motor performance in a shape sorter task: A longitudinal study from 14 to 36 months of age in children with an older sibling ASD

Date Published: May 28, 2019

Publisher: Public Library of Science

Author(s): Fabrizio Taffoni, Valentina Focaroli, Flavio Keller, Jana Marie Iverson, Lucia Billeci.


During development, motor skills are fundamental in supporting interactions with the external world. The ability to plan actions is a particularly important aspect of motor skill since it is involved in many daily activities. In this work, we studied the development of motor planning longitudinally in children with an older sibling with Autism Spectrum Disorder (ASD) who are at heightened risk (HR) for the disorder and children with no such risk (low risk; LR) using a shape sorter task. Children were observed at 14, 18, 24 and 36 months. Three HR children with a later diagnosis of ASD (HR-ASD) were analyzed separately from the rest of the sample. Behavioral and kinematic data indicated that precision demands significantly influenced children’s actions, and that children’s performance improved with age. No differences were found between the HR and LR groups, but a descriptive analysis of data from the three HR-ASD suggested differences in the variables describing children’s action (as reaching time and acceleration) as well as variables describing children’s performance (as the adjustment of the shapes).

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The ability to interact with the environment and to explore the world around us is a key ingredient in early development: not only does it promote the acquisition of new motor skills, but it also supports development in other fundamental domains (e.g., cognition, communication; e.g., [1]). The progressive acquisition of new motor skills provides infants with enriched possibilities for interacting with the environment and promotes the acquisition of language and the development of social skills [2, 3].

In this research, we examined the development of motor planning in an object fitting task. Our aim was to study planning skill during reaching and object placement and its development longitudinally in HR and LR children. Statistical analyses compared performance and patterns of age-related change between the HR and LR groups between 14 and 36 months of age.

In this research, we studied the development of the ability to plan actions involving the transport, alignment, and placement of objects longitudinally in HR children with familial risk for ASD and LR children with no such risk using the shape sorter task devised by [25]. Performance in this task reflects a constellation of developing motor, perceptual, and cognitive skills. An innovative feature of this study was the use of magneto-inertial sensors worn by the child and housed in the shape blocks. This approach allowed us to collect quantitative data not only on the kinematics of reaching and placement, but also on the orientation of the block. In addition, while previous research has focused primarily on the placement phase of children’s actions, we also examined the reaching phase to assess planning skills prior to object insertion.