The Role of Gender and Nap Status in Executive Functioning of Four-Year Old Korean Children

Abstract

Most children discontinue daytime napping by the age of five. This study investigated the role of nap status and gender in executive functioning of Korean four-year olds, about half of whom have transitioned out of naps. Thirty-seven children living in the Gyeonggi-do area in South Korea participated in this study. A sleep diary filled out by parents was used to identify their nap habits and their executive function was assessed using the Fish Flanker Task involving three phases (standard, reverse, mixed). Looking at speed, reaction-time analyses suggested that girls take longer to warm up on the standard flanker task compared to boys a difference that diminishes by the next phase when children encounter the reverse flanker task. Looking at accuracy, children were slow to warm up. Although there were no differences in initial exposure to the standard flanker task, children were more accurate on congruent than incongruent trials in the the mixed phase regardless of nap status or gender. When shifting from the standard flanker to the reverse flanker task, habitual nappers were more accurate on incongruent trials in the reverse-flanker task compared to non-habitual nappers. There were no statistically significant differences in duration of nighttime sleep for habitual and non-habitual nappers supporting the idea that the advantage in accuracy on incongruent trials for habitual nappers was due to the nap. The results suggest that four-year olds may still receive a cognitive benefit from habitual naps, especially when they must shift between tasks.