Background and aims The human brain is highly susceptible to the consequences of preterm birth. Cognitive tasks vary in complexity and resource requirements, thus performance on tasks with different demands may provide information on specific cognitive differences in children related to the degree of prematurity. Mathematical performance requires simultaneous processing of information which is particularly compromised in preterm children. Our aim was to investigate the relationships between task complexity and incremental performance deficits across the full spectrum of gestational age (GA).
Methods 1,513 children ranging from 27 to 43 weeks GA were studied from birth to 8; 5 years as part of a prospective geographically defined longitudinal investigation of neonatal at-risk children in South Germany (Bavarian Longitudinal Study). Children’s cognitive performance at 8; 5 years was measured with K-ABC subtests Number recall, Pattern reasoning, and Calculating and with a standardized mathematics test.
Results Results were twofold:
Preterm children showed incremental performance deficits with increasing task complexity.
There was a curvilinear relationship between GA and task performance with a point of change around 32 weeks of GA.
In general, every lost week of gestation increased the adverse impact on performance. However, this relationship was strongest among tasks which required the highest cognitive workload.
Conclusions With increasing cognitive workload preterm children fall behind in test scores. This suggests that brain organisation or damage limits cognitive resources. The relationship between GA and task performance is curvilinear. Our approach may offer a theoretical foundation to scrutinize the cognitive characteristics of the preterm phenotype.