Socio-demographic characteristics of participants [n (%)].

a)<p>Dada may not sum up to n = 206 in School A due to non-response.</p>c)<p>Dada may not sum up to n = 221 in School B due to non-response.</p>b)<p>and^d) Dada sum up to 100% due to calculation not included non-response.</p>e)<p>A chi-square test or Fisher’s exact test was used to compare categorical variables.</p><p>^f)Monthly income per capita.</p

Summary of results from multiple linear regression models.

a)<p>Independent variables included exposure status(0 = school A, 1 = school B), age(years), years of education(years), familiarity with computer games (0 = little to none, 1 = much), sex(0 = male, 1 = female), length of residency(years), body mass index(BMI), second-hand smoking (0 = no,1 = yes), sleep status(0 = bad, 1 = not bad, 2 = good), household fuel (0 = coal, 1 = liquified petroleum gas, 2 = electricity, 3 = others), high-tension lines surrounding residence (0 = no,1 = yes) and frequent use of household appliances(0 = no,1 = yes).</p>b)<p>4 different multiple linear regression models were done considering NAI scores of VRT, DSB, VSRT and PAT as dependent variables. Backward selection for independent variable was used in the model with the entry significance level set to 0.05 and a removal level of 0.10.</p>#<p>Independent variable reserved in the model was with a p-value <0.05;</p>*<p>Independent variable reserved in the model was with a p-value <0.001.</p><p>Beta = standardized coefficients; VRT = visual retention test; DSB = digit symbol; VSRT = visual simple reaction time; PAT = pursuit aiming test.</p

ANOVA results from computerized neurobehavioral testing.

a)<p>4 different ANOVAS were done considering NAI scores of VRT, DSB, VSRT and PAT as dependent variables.</p>*<p>Compared with students in School A, P<0.05.</p><p>VRT = visual retention test; DSB = digit symbol; VSRT = visual simple reaction time; PAT = pursuit aiming test.</p

Power frequency electric field measurements (V/m).

#<p>Reference limit came from the Technical Regulations on Environmental Impact Assessment of Electromagnetic Radiation Produced by 500 kV Ultrahigh Voltage Transmission and Transfer Power Engineering (HJ/T24-1998) in China.</p>**<p>Two-Independent Samples Nonparametric Test, Z = 3.981, p<0.001.</p><p>N = number of spot measurements; M = median = P₅₀; IR = interquartile range = P₇₅–P₂₅.</p

Socio-demographic characteristics of participants (Mean ± SD).

<p>^a)One-way analysis of variance was used for continuous variables; BMI = body mass index.</p

Investigation of EMF exposure from sources other than HVT lines.

a)<p>Dada may not sum up to n = 206 in School A due to non-response.</p>c)<p>Dada may not sum up to n = 221 in School B due to non-response.</p>b)<p>and^d) Dada sum up to 100% due to calculation not included non-response.</p>e)<p>It was defined as the use of one or more of the household appliances, namely computers, TVs, mobile phones and fixed-line telephone in daily life.</p>*<p>Compared with students in School A, P<0.05.</p