Tablet Use Affects Preschoolers' Executive Function: fNIRS Evidence from the Dimensional Change Card Sort Task.

This study aims to examine the impact of heavy use of tablets on preschoolers' executive function during the Dimensional Change Card Sort (DCCS) task using the functional near-infrared spectroscopy (fNIRS). Altogether, 38 Chinese preschoolers (Mage = 5.0 years, SD = 0.69 years, 17 girls) completed the tasks before the COVID-19 lockdown. Eight children never used tablets, while 16 children were diagnosed as the 'heavy-user'. The results indicated that: (1) the 'non-user' outperformed the 'heavy-user' with a significantly higher correct rate in the DCCS task; (2) the two groups differed significantly in the activation of the prefrontal cortex (BA 9): the 'non-user' pattern is normal and healthy, whereas the 'heavy-user' pattern is not normal and needs further exploration.