Performance during Object Retrieval Tasks in Typical
Infants and Infants with DS
In this study, we are extending our current knowledge about object play
in children with DS to a specific functional skill, object
retrieval . Object retrieval requires means-ends exploration, i.e.,
planning and executing different strategies as a means to achieve an end
goal of toy retrieval, and has been extensively studied in the typical
population using tasks such as retrieving an object from a concealed
container or pulling a cloth to retrieve a toy located at the end of the
cloth (Piaget, 1953; Willatts, 1999). In TD infants, the ability to
successfully retrieve objects usually emerges during the end of first
year, however, infants continue to refine this skill in the second year
of life. Bruner (1970) examined the development of object retrieval
during the first 2 years of life and indicated that infants younger than
6-8 months old were unsuccessful in the task. Older infants between 9-17
months were successful but infants seem to refine this skill with
increasing age such that infants between 9 and 11 months used unimanual
strategies, infants between 12 and 14 months used bimanual strategies,
and infants between 15 and 17 months used complex (more refined)
bimanual strategies to retrieve the toy (Bruner, 1970). Means-ends
exploration and object retrieval skills depend on the motor (Bojczyk &
Corbetta, 2004), perceptual (Babik et al., 2019), and cognitive skills
of children (Willats, 1999; Sommerville & Woodward, 2005). Furthermore,
means-ends exploration is a crucial development skill and is closely
associated with the development of goal-directed behaviors, problem
solving skills, and intentionality (Willats, 1999; Babik et al., 2019).
In contrast to the TD infants, there is a relative dearth of studies on
the development of object retrieval skills in infants and children with
DS (Schworer et al., 2020; Fidler, Hepburn, et al., 2005). When compared
to TD controls, 4- to 12-months old with DS took longer to execute
strategies such as pulling a cloth and grasping a toy while trying to
retrieve a toy located at the end of a 12-inch cloth (Schworer et al.,
2020). Similarly, 2- to 3-year-old children with DS produced fewer
effective strategies while trying to retrieve a toy/snack from a clear
plexiglass box with an opening on one side (Fidler, Hepburn, et al.,
2005). Furthermore, object retrieval strategies were associated with the
non-verbal behaviors of children with DS, such that children with poor
retrieval strategies (e.g., more reaching failures) showed fewer
non-verbal behaviors in social contexts (e.g., less looking/pointing at
objects and less requesting of social routines like tickling) (Fidler,
Philofsky, et al., 2005). Overall, existing evidence indicates that
infants and children with DS are less successful than their TD peers in
means-ends exploration tasks requiring the retrieval of hidden objects.