Delay of gratification and time comprehension is impaired in very preterm children at the age of 4 years

Abstract

BackgroundVery 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. AimsWe 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 designVery 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. Subjects25 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 measuresCorrect answers in the time comprehension and receptive language task, waiting time in the delay-of-gratification task were measured. ResultsPreterm 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). ConclusionsPreterm 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.