ABSTRACT
Objective:To explore the developmental characteristics of Chinese semantic and orthographic processing in normal school-age children by event-related potential (ERP) technique.Methods:Children aged 7-11 in an ordinary primary school in Changzhou were randomly selected and divided into 7-year old group ( n=21 ), 8-year old group ( n=21), 9-year old group ( n=19), 10-year old group ( n=20) and 11- year old group ( n=22) according to their age.ERP was recorded while subjects completed the Chinese character semantic activation task and pseudo word judgment task. Then the N400 and P200 amplitudes of school-age children under the conditions of semantic correlation, semantic uncorrelation and pseudo word judgment were collected, and the data were analyzed by three factors mixed design ANOVA.Data of behavioral accuracy and response time were analyzed by one-way ANOVA and Bonferroni correction was used for multiple hypothesis testing. The statistical software was SPSS 25.0. Results:(1)Behavioral results: the accuracy of semantic related and semantic unrelated tasks of children in the five groups aged 7, 8, 9, 10 and 11 were statistically significant ( F=15.55, 4.01, both P<0.01), and the accuracy of children in the 7-year old group was significantly lower than those in the other four groups (all P<0.05). There was no significant difference in the accuracy of pseudo word judgment task among the five groups ( F=0.68, P=0.609). The response time of children in the five groups under semantic related and semantic unrelated tasks was significantly different ( F=3.90, 3.13, both P<0.05). The response time of the 11-year old group under semantic related tasks was significantly shorter than those of the 7-, 8- and 9-year old groups (all P<0.05). The response time of the 7-year old and 11-year old groups under semantic unrelated tasks was significantly shorter than those of the 8-, 9- and 10-year old groups (all P<0.05). (2)ERP results: N400 amplitudes of 7-, 8-, 9-, 10- and 11-year old children under semantic related tasks were significantly smaller than those under semantic unrelated tasks and pseudo word judgment tasks (all P<0.05). The N400 amplitude of the subjects gradually decreased with the increase of age, except that there was no statistical difference between the 10-year old and 11-year old groups under the semantic related task, between the 8-year old and 9-year old groups under the semantic unrelated task and the pseudo word judgment task, and between the 10-year old and 11-year old groups (all P>0.05), there were statistical differences between the other age groups (all P<0.05). P200 amplitude of semantic related task at 7-, 8-, 9- and 10-year old was significantly higher than that at semantic unrelated task (all P<0.05), and the amplitude of semantic related task at 7-, 8-, 10- and 11-year old was significantly higher than that at pseudo word judgment (all P<0.05). The amplitude of P200 gradually increased with age, and there were significant differences in pairwise comparison among other age groups ( P<0.05), except semantic related task and unrelated task among 7-, 8- and 9-year old groups, between 10- and 11-year old groups, and pseudo word task between 7- and 8- years old groups, 10- and 11- year old groups (all P>0.05). Conclusion:The semantic processing and orthographic processing of school-age children develop with age in a unique way. The age of 7 is an important period for cognitive development of Chinese language.The age of 8-9 may be a sensitive period for the development of brain plasticity, and the development slows down at the age of 10-11.
ABSTRACT
Objective To investigate the lipid levels of Han ethnicity Chinese children at school-age,to provide objective data for the formulation of prevention and management strategy regarding dyslipidemia among children and adolescents.Methods 20 191 children (with 10 669 boys and 9522 girls) aged 7 to 16 years old from 6 representative geographical areas,including Beijing,Tianjin,Hangzhou,Shanghai,Chongqing and Nanning,were surveyed in a randomly selected clustered sample in China.Data on fasting blood triglyceride (TG),total cholesterol (TC),lowdensity lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels were measured.Non-high-density lipoprotein cholesterol (non-HDL-C) levels were calculated with data collection,entry,and collation were under the same criteria.Results (1) In the 7-16 year-old group,TG (P95) fluctuated between 1.26 mmol/L and 1.88 mmol/L,while TC (P95) was between 4.80 mmol/L and 5.46 mmol/L.LDL-C(P95) was between 2.67 mmol/L and 3.27 mmol/L while non-HDL-C (P95) was between 3.36 mmol/L and 3.91mmol/L,sugesting that age did not seem to be an affecting factor for the lipid level (P＞0.05).The level of HDL-C (P5) fluctuated bctwcen 1.08 mmol/L and 0.83 mmol/L,and the dependability analysis on HDL-C and age showed statistically significant difference (P＜0.01,r=-0.274).(2) In the 7-9 year-old group,the levels ofTG,TC,LDL-C and non-HDL-C of boys were lower but the HDL-C level was higher than in girls.However,in the 10-16 year-old group,the levels of five lipids of boys were all lower than in girls,with all the differences statistically significant (P＜0.05).(3) The levels of TG,TC,LDL-C and non-HDL-C in the obese group were significantly higher than those in non-obesity group,as HDL-C was significantly lower than in non-obese group(P＜0.01).Incidence rates of single and multiple dyslipidemia in obese group were significantly higher than in non-obese group (P＜0.01).(4) Grouped by region,the abnormal rates of TG were descending,with the ranking as North (10.4％),Midwest (9.7％) and East (8.3％),while the abnormal rates of TC were descending with the ranking as Midwest (6.0％),North (5.2％)and East (4.8％).The abnormal rates of LDL-C were descending as the ranking of North (3.1％),East (2.6％) and Midwest (0.9％),with the abnormal rates of non-HDL-C were descending as Midwest (6.5％),North(4.2％)and East (3.6％).The abnormal rates of HDL-C were descending as Midwess (14.2％),North(5.7％) and East(5.5％).All the differences in the above-said items were statistically significant (P＜0.05).(5) According to the standards of hyperlipidemia formulated by the American Academy of Pediatrics,the incidence rates of abnormal TG,TC,LDL-C,non-HDL-C,HDL-C were 9.4％,5.4％,2.2％,4.8％,8.6％ respectively.Conclusion (1) Levels of lipids were affected by many factors,but age was not one of them in children and adolescents.However,HDL-C was declining along with the increase of age,to some extent.(2)Girls had a relatively protective tendency through the increasing HDL-C level when they entered the puberty years.(3)Lipids levels in non-obese group were significantly better than the obese group.(4)The lipids levels of children and adolescents in the Eastern region of the country were better than that in the northern and mid-western areas.