Correlation of self-reported sleep duration with working memory of adolescents

With the increasing use of electronic devices and social media, the duration of sleep has consistently reduced in adolescents. Sleep restriction eventually leads to cognitive performance declines. Poor sleep and working memory difficulties are both associated with learning difficulties leading to poor academic performance.

We postulated that decreased sleep duration decreases the working memory of adolescents and eventually their academic performance.

Cross-sectional Study.

The study was conducted on 114 school students; 62 boys and 52 girls (age 13.8 ± 0.91 and 13.65 ± 0.88 years, respectively). Sleep was monitored by self-reported diary. Working memory was tested by the n-back task. The students were given 1-back and 2-back visual tasks in two blocks and accuracy of each of the tests was calculated.

Prism software was used and Mann-Whitney-U test and Spearman Correlation tests were employed.

Sleep duration range was 4.15-12 hours with a mean of 7.63 ± 1.35 hours. The sleep duration in males and females, respectively was 6.94 ± 0.94 hrs. and 8.5 ± 1.31 hrs.; significant (p = 0.0001). The total n-back score accuracy (1-back and 2-back) was 52.11 ± 17.32% in males and 52.24 ± 17.40% in females (p = 0.976). Spearman Correlation between sleep-duration and total n-back score was not found to be statistically significant (p = 0.611). However, the correlation of total n-back score with academic performance was statistically significant.

The working memory was not statistically different in males and females, and was not significantly correlated with sleep duration, though it was significantly associated with the academic performance.