The study habits at home are important contributors to lifestyle and they affect cognitive ability. However, there is no research on the effect of study habits at home on the brain structure of children, which is the purpose of this study.
Data of 229 healthy children (111 males and 118 females; aged 5.6-18.4 years) who joined our experiment twice, with a 3-year interval (time 1 and time 2) were analyzed for our study. All subjects and their parent gave informed consent in the study, which was approved by the local ethical committee. MRI scans and Wechsler IQ test were conducted at both time 1 and time 2. Behavioral data such as study time at home were collected at time 1. We conducted voxel-based morphometry analysis and applied multiple regression analysis to reveal the correlation between longitudinal change in rGMV/ rWMV, and study time at home and IQ subscales where the effect of study time at home was seen.
We found a significant positive correlation between study time at home and change in the Verbal comprehension index (VCI), (P = 0.038, β= 0.134). The whole-brain analyses revealed a significant positive correlation between study time at home and rWMV in the right superior frontal gyrus (SFG), (P < 0.05 voxel-wise FWE-corrected). There was the significant positive correlation between changes in VCI score and changes in rWMV in the right SFG in the ROI analysis (P < 0.05 voxel-wise FWE-corrected, SVC within the cluster identified above).
Our study revealed that longer study time at home was associated with an increase in VCI score, increase in rWMV in the SFG which in turn explained the increase of the VCI score. The increase in rWMV might be due to use dependent change in myelin, spine axon and glia caused by studying. Our study suggested the study time at home develops children's verbal skills as well as development of rWMV in the SFG which is known to be involved in diverse higher order cognitive processes including memory control.