Effects of multiple planning constraints on the development of grasp posture planning in 6- to 10-year-old children.

Abstract

This experiment examined how multiple planning constraints affect grasp posture planning in 6-to 10-year-old children (n ϭ 16 in each group) by manipulating the intended object end-orientation (left end-down, right end-down) and initial precision demands (standard, initial precision) of a bar transport task. Results indicated that grasp posture planning was strongly influenced by multiple planning constraints. During the standard condition the sensitivity toward comfortable final hand postures (end-state comfort) was similar for all age groups in right end-down trials, and corresponded to values reported in adult populations. In contrast, there was an age-related increase in end-state comfort compliance during left end-down trials. During the initial precision condition end-state comfort was similar across all groups for left end-down trials. However, end-state comfort compliance was significantly lower for the 6-year-old children than in all other age groups for right end-down trials. In sum, the ability of children to plan their goal-related movements is influenced by the presence of task-related constraints that increase the overall cognitive demands of the task. The demands associated with selecting the appropriate grasp posture during the most cognitive demanding condition required more cognitive resources than 6-to 10-year-old children possess. Removing the conflict between the goal-directed and habitual systems reduces some of these costs, with data indicating that the ability to integrate multiple planning constraints first emerges at 7 years of age, and improves over the developmental spectrum.

The development of tool use: Planning for end-state comfort.

“…Indeed, tests of children’s cognitive ability—inhibition with an Animal Stroop task, and planning with the Tower of London game—were positively correlated with performance on an end-state comfort task (Stockel & Hughes, 2015b). Although using different language to describe how a child chooses among grips, Stockel and Hughes (2015a) analysis agrees with Siegler’s (1996) model in postulating that competing strategies with various levels of strength lead to greater instability in behavior. Several researchers have proposed competing processes to explain how behavior changes over time.…”

“…The “goal-directed system” takes into account future requirements and if allowed will select the underhand grip. Stockel and Hughes (2015a) went on to show that when additional precision constraints to the initial grasp were added, reduced levels of the underhand grip were seen in all ages tested (6 to 10 years of age). They concluded that greater cognitive costs interfered with planning and increased the competition between the habitual and goal-directed systems.…”

End‐state comfort in two object manipulation tasks: Investigating how the movement context influences planning in children, young adults, and older adults

“…Children, young adults, and older adults performed each task in three different movement contexts. Findings however, more recent work (e.g., Stöckel & Hughes, 2015), has observed 6-year-old children's motor planning was adult-like in their study. Stöckel and Hughes (2015) suggested that grasp postures of young children reflect a bias toward performing actions successfully executed in the past, due to cognitive demands outweighing available cognitive resources.…”

“…Findings however, more recent work (e.g., Stöckel & Hughes, 2015), has observed 6-year-old children's motor planning was adult-like in their study. Stöckel and Hughes (2015) suggested that grasp postures of young children reflect a bias toward performing actions successfully executed in the past, due to cognitive demands outweighing available cognitive resources. With age, children are better able to integrate multisensory information to consider future demands and thus demonstrate action suitable for task which require second-order planning (Stöckel & Hughes, 2015).…”

“…Findings with older adults are in line with Scharoun et al (), who suggested cognitive development and decline to explain similarities in behavior at either end of the lifespan. Findings with children are concurrent with a systematic review of end‐state comfort (Wunsch et al, ); however, more recent work (e.g., Stöckel & Hughes, ), has observed 6‐year‐old children's motor planning was adult‐like in their study.…”