Working memory and sleep in 6- to 13-year-old schoolchildren.
OBJECTIVE
To study the associations between sleep quality/quantity and performance in auditory/visual working memory tasks of different load levels.


METHODS
Sixty schoolchildren aged 6 to 13 years from normal school classes voluntarily participated. Actigraphy measurement was done during a typical school week for 72 consecutive hours. It was timed together with the working memory experiments to obtain information on children's sleep during that period. The n-back task paradigm was used to examine auditory and visual working memory functions.


RESULTS
Lower sleep efficiency and longer sleep latency were associated with a higher percentage of incorrect responses in working memory tasks at all memory load levels (partial correlations, controlling for age, all p values < .05, except in visual 0-back and auditive 2-back tasks); shorter sleep duration was associated with performing tasks at the highest load level only (partial correlations, controlling for age,p < .05). Also in general linear models (controlling for age, gender, and socioeconomic status), sleep efficiency (F = 11.706, p = .050) and latency (F = 3.588, p = .034) were significantly associated with the mean incorrect response rate in auditory working memory tasks.


CONCLUSIONS
Sleep quality and quantity affect performance of working memory tasks in school-age children. In children with learning difficulties the possibility of underlying sleep problems should be excluded.
Steenari
Maija-Riikka
MR
Hospital for Children and Adolescents, Child Psychiatry, Helsinki University Central Hospital, Finland.
Vuontela
Virve
V
Paavonen
E Juulia
EJ
Carlson
Synnove
S
Fjallberg
Mika
M
Aronen
EevaT
E
D000293:Adolescent; D002648:Child; D005260:Female; D005387:Finland; D006801:Humans; D016014:Linear Models; D008297:Male; D008570:Memory, Short-Term; D011930:Reaction Time; D012890:Sleep; D018709:Statistics, Nonparametric