Chronotype and time-of-day effects on spatial working memory in preschool children

Nur K. Abdul Jafar, Elaine K. H. Tham, Derric Z. H. Eng, Anne Rifkin-Graboi, Joshua J. Gooley, Daniel Y. T. Goh, Oon-Hoe Teoh, Yung S. Lee, Lynette Pei-Chi Shek, Fabian Yap, Peter D. Gluckman, Yap-Seng Chong, Michael J. Meaney, Shirong Cai, Birit F. P. Broekman

Research output: Contribution to journalArticleAcademicpeer-review

2 Citations (Scopus)

Abstract

STUDY OBJECTIVES: Spatial working memory (SWM) capacity subserves complex cognitive functions, yet it is unclear whether individual diurnal preferences and time-of-day influence SWM in preschool children. The main and interaction effects of chronotype and time-of-day on SWM and SWM differences in preschoolers with different chronotypes within each time-of-day group will be examined. METHODS: We studied a subset of typically developing 4.5-year-olds taking part in a birth cohort study (n = 359). The Children's Chronotype Questionnaire categorized children into morning-, intermediate-, and evening-types. Using a computerized neuropsychological test (Cambridge Neuropsychological Test Automated Battery), SWM was determined from the total number of between-search errors (ie, between search-total errors) and Strategy scores. Higher between search-total errors or lower Strategy scores indicated worse SWM. Time-of-day was categorized into late morning (10:00 am to 11:59 am), afternoon (12:00 pm to 3:59 pm), and late afternoon (4:00 pm to 6:30 pm). In a subsample (n = 199), caregiver-reported chronotype was validated using actigraphy-measured sleep midpoint. RESULTS: After controlling for ethnicity, no significant main and interaction effects of chronotype and time-of-day on between search-total errors and Strategy scores were seen (all P > .05). However, evening-types outperformed morning-types (ie, lower mean between search-total errors) in the late afternoon (P = .013) but not in the late morning and afternoon (all P > .05). Actigraphy data in the subsample confirmed that evening-types had later sleep midpoints during weekdays and weekends (P < .001). CONCLUSIONS: Since evening-type preschoolers had better SWM in the late afternoon compared to morning-type preschoolers, this gives insights into optimal learning opportunities in early childhood education. CITATION: Abdul Jafar NK, Tham EKH, Eng DZH, et al. Chronotype and time-of-day effects on spatial working memory in preschool children. J Clin Sleep Med. 2023;19(10):1717-1726.

Original languageEnglish
Pages (from-to)1717-1726
Number of pages10
JournalJournal of clinical sleep medicine
Volume19
Issue number10
DOIs
Publication statusPublished - 1 Oct 2023

Keywords

  • actigraphy
  • chronotype
  • preschool children
  • spatial working memory
  • time-of-day

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