INTRODUCTION
Exploring and playing with objects are integral parts of early
development and infants show substantial changes in exploratory
behaviors over the first few years of life (Belsky & Most, 1981;
Bornstein et al., 2013). In contrast, children with developmental
disabilities such as Down syndrome (DS) tend to be less engaged with
objects and explore them less actively (de Campos et al., 2013; Fidler
et al., 2019; Landry & Chapieski, 1989; MacTurk et al., 1985; Venuti et
al., 2009). DS is one of the most common chromosomal disorders with an
estimated prevalence of 1 in 700 live births (Parker et al., 2010).
Atypicalities in object play in individuals with DS are evident as early
as the infancy period and persist throughout the childhood period (de
Campos et al., 2010; 2011; 2013; Fidler, Hepburn, et al., 2005; Fidler
et al., 2014). For example, infants with DS between 4- to 6-month-old
showed less successful grasping and fewer exploratory behaviors
including reaching, banging, and rotating during an object exploration
task compared to chronological age-matched TD infants (de Campos et al.,
2010; 2013).11Although infants with DS are documented to show
less active or reduced exploration of toys, recent work by Fidler et
al (2019) indicates that this characterization of less active
exploration may accurately reflect only a subset of infants with DS.
Similarly, school-aged children with DS were observed during a 2-minute
free play with random set of toys such as plastic coins, bracelet bands,
and paper cups (Fidler et al., 2014). During the play session, children
with DS were less likely to initiate actions on new toys (i.e.,
previously unexplored toys) and less likely to show novel functional
actions (i.e., previously undemonstrated functional actions) compared to
mental-age matched TD children and children with other development
disabilities (Fidler et al., 2014). Overall, infants and children with
DS show significant delays in their ability to meaningfully explore
objects compared to mental-age matched TD children.