The effect of task complexity on planning in preterm-born children

Objective: Planning is an important executive function (EF) skill that is fundamental to the capacity to achieve everyday goals that require a series of intermediate steps. This study examined the effect of preterm birth on planning skills in early and middle childhood using Tower problems that made different cognitive workload demands.

Method: We administered a novel touchscreen Tower of Hanoi task (Monkey Tree Task; MTT) in three age cohorts (3, 6, and 9 years) to 485 children born between 2000 and 2010 (105 extremely low birth weight [ELBW], 248 late preterm [LP], and 132 term-born [Term]).

Results: Children born with ELBW completed significantly fewer Tower problems with higher cognitive demands than children born at Term or LP. Likewise, Term- and LP-born children completed more Tower problems than children born with ELBW. In the youngest cohort, Term-born children solved Tower problems more efficiently than either preterm group, and LP-born children solved problems more efficiently than those born with ELBW. However, there were no group differences in efficiency in the older age cohorts. Significant correlations between our MTT measures and performance on other EF tasks were found.

Conclusions: The MTT captured significant performance differences in planning skills between children born term vs. preterm. This study provides important information on the impact that cognitive workload, as a function of Tower problem complexity, has on planning skills in preterm children. This study adds to a growing body of research that distinguishes LP birth as having subtle, but distinguishable, adverse neuropsychological outcomes at earlier ages.