Development of cool and hot executive function deficit in children born very low birth weight with normal early development: A longitudinal cohort from aged 6 to 10

Background: Studies showed preterm children born with very low birth weight (VLBW, <1500 g) are at risk for poorer executive functions (EFs). However, very little research has been reported longitudinally on the development of both cool and hot EFs deficits in preschool to school-age VLBW preterm children with normal early development. Aims: Present study aimed to investigate the development of cool and hot EFs in VLWB preterm children longitudinally. Methods: Forty preterm children born VLBW were followed up at ages 6, 8, and 10. Fifty term-born controls were recruited at each age stage. Cool EFs was assessed using backward digit span subtest of WISC-IV, Knox's Cube Test, Comprehensive Non-verbal Attention Test Battery (CNAT), Tower of London (ToL), Wisconsin Card Sorting Test (WCST), and hot EFs was assessed using Theory of Mind (ToM) and Delay of Gratification (GIFT) tasks. Results: The six-year-old VLBW preterm group showed significantly lower scores of planning in ToL, inhibition control in CNAT, and in both ToM and GIFT tasks. There is no significant difference in average cool and hot EFs between the eight and ten-year-old preterm group and the control group. Conclusions: At six, VLBW preterm infants with normal early development have delayed cool and hot EFs development. Although the average performance of EFs can reach the level of the control group with age increasing to eight and ten years, there are still individual differences. It is recommended that more complete development indicators be established in the future, and early intervention should be made for VLBW premature children with delayed EFs.