Posture Matters: Object Manipulation During the Transition to Arms-Free Sitting in Infants at Elevated vs. Typical Likelihood for Autism Spectrum Disorder

Abstract

Aims: We investigated how infants grasped and transferred toys over a four-week period as they transitioned to arms-free sitting. We compared object manipulation in infants with typical likelihood (TL) and elevated likelihood (EL) for autism spectrum disorder (ASD) as they sat with vs. without support.

Methods: Eighteen infants (7 EL; 11 TL; 5–8 months of age at the start of the study) were observed during three sessions at home across the transition to arms-free sitting. At each session, toys were presented to the infants in two different postures: sitting with support from a boppy pillow and sitting independently. Mean percentage of time spent grasping and rates of transferring objects between two hands were calculated for each infant at each session.

Results: Both grasping time and transfer rate increased across the transition to arms-free sitting. EL infants, but not TL infants, spent significantly less time grasping toys when sitting independently than when sitting with support.

Conclusions: Sitting plays a significant role in the development of object manipulation skills. Our results reveal a need to examine object manipulation skills in multiple posture contexts, especially in infants who exhibit motor delays.

Keywords:

• Infant development
• early intervention
• motor development
• autism
• pervasive developmental disorders

Acknowledgments

This article is based on an honors thesis submitted to Carnegie Mellon University by the first author in partial fulfillment of the requirements for the degree of Bachelor of Science. Miranda Mlincek is now at Massachusetts General Hospital Institute of Health Professions. We thank Edward Lin and Haarika Chalasani for serving as secondary coders on this project and Joshua Schneider for creating line drawings. Special thanks to members of the Infant Communication Lab, University of Pittsburgh, for assistance with data collection; Holly Gastgeb for assistance with outcome assessments; and the families and infants who participated in this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 Literature focusing on the infant siblings of children with an ASD has typically referred to them as “high risk,” referring to a heightened biological probability of receiving an eventual ASD diagnosis. Unfortunately, the terms “risk” and “high risk for ASD” are rooted in the medical model view of autism, and thus they carry deeply negative connotations. While autism often reflects challenges that require substantial support, for many autistic people, autism represents a valued part of their identities (e.g., Dunn & Andrews, 2015) for which the term “risk” and person-first language are stigmatizing (Gernsbacher, 2017; Kenny et al., 2016; Robison, 2019). For these reasons, here we use the term “elevated likelihood” and “EL infants” when referring to infants with an older sibling with an ASD diagnosis.

Additional information

Funding

This research was supported by a Carnegie Mellon University Summer Undergraduate Research Fellowship to MM, NIH R01 HD073255 to JMI, and UL1 RR024153 and UL1TR000005. The authors report no conflicts of interest.

Notes on contributors

Miranda M. Mlincek

Miranda M. Mlincek is a graduate student at the MGH Institute of Health Professions pursuing an entry-level Doctor of Occupational Therapy (OT D) degree. She received a Bachelor of Science in Neuroscience from Carnegie Mellon University in 2019.

Emily J. Roemer

Emily J. Roemer is a graduate student in the joint Clinical and Developmental Psychology PhD program at the University of Pittsburgh. She received a Bachelor of Science in Brain & Cognitive Sciences from the University of Rochester in 2015 and plans to pursue a career in autism research.

Christen Kraemer

Christen Kraemer received a bachelors degree from the University of Pittsburgh in 2017 and is a second year student in the Clinical Mental Health Counseling Program at Indiana University of Pennsylvania. She is interested in person-centered counseling with children of all ages to encourage development and independence.

Jana M. Iverson

Jana M. Iverson is a professor in the Department of Psychology at the University of Pittsburgh. She received her PhD in Psychology from The University of Chicago and completed a postdoctoral fellowship at Indiana University. She is a Fellow of the Association for Psychological Science.