RESUMO
BACKGROUND: Very preterm infants more likely exhibit deficient executive functions than term born controls. Delay of gratification, as part of the executive functions, allows for rejecting an immediate in favor of a greater future reward. Time comprehension might help to delay gratification. AIMS: We hypothesized that delay of gratification and time comprehension is less developed in preterm children and that time comprehension is associated with the ability to wait for a greater reward. STUDY DESIGN: Very preterm children (<32weeks' gestation) and term born controls were tested for receptive language skills, time comprehension and delay of gratification at the (corrected) age of 4years. SUBJECTS: 25 preterm subjects (12 female; median: gestational age (GA) 28.3weeks, corrected age 4years, 22days) and 26 controls (16 female, median GA: 40.0weeks, age 4years, 25days) participated. OUTCOME MEASURES: Correct answers in the time comprehension and receptive language task, waiting time in the delay-of-gratification task were measured. RESULTS: Preterm subjects had less time comprehension than controls (43% vs. 53%, p=0.017, one-tailed) but receptive language skills were similar. Waiting time in the delay-of-gratification task was 3:42min in preterm subjects, versus 10:09min in controls (p=0.043, one-tailed). Even after controlling for language skills, waiting time correlated positively with time comprehension in both groups (r=0.399, p=0.004, two-tailed). CONCLUSIONS: Preterm children's time comprehension and delay of gratification ability is impaired. Future research is warranted to investigate whether training in time comprehension increases the ability to delay gratification.
