Charting The Developmental Trajectories Of Visual Attention And Executive Function Of Normal Pupils And Adolescents

Attention is the focus of the mind, which can be selected, shifted and divided. It is the cognitive course to select one object or event from some irrelevant objects. The executive function is to use complex strategy, plan, and monitor response while solving problem. The ability to focus objects and events is the first principle cognitive function to survive, and the same is executive function. But there are many children who suffered from those malfunction, such as ADHD, learning disability, schizophrenia and so on. Most of research on the relativity of gene and cognitive indicates that it is important to study each cognition under developmental condition. In order to know the mechanisms and developmental course of those abnormal functions, we should understand how the normal attention and executivefunction are developed. But few developmental studies across whole childhood are carried out and there are almost blank in our country, and there are few comparison studies on different attention components and executive function. By randomized sampling, we recruited 576 children and adolescents from a primary school and a middle school at a county. Using the computerized program, we are trying to chart the developmental trajectory of visual attention and executive function in normal children from 6 to 18 years. We studied some components of visual attention and the executive function about concept forming and set-switching, and observed the age and gender effects on those functions, r-nd explored whether those components of attention and executive function develop in parallel.Part one The selective attentionMethods The part of selective attention study held three single-task visual search tests . In the first one, subjects were told to find out the special black upright ellipses around many non-targets with different color or shape or direction;the second and the third tasks were to find out the red horizontal ellipses, but in the third task equal number of red horizontal ellipses flatter than the targets were added. The correct hits, total clicks, mcr-m time per hits, meandistance per hits and four kinds of errors were recorded by program. The mean measure of task one and task two were serviced as the measures of selective attention.Results The data from 555 subjects were recorded. The measures of selective attention were different in different age and gender. Girls have higher accuracy but slower speed than that of boys. By curve regression the results indicated that the relationship between the accuracy and the speed with age were quadratic. The accuracy was close to mature level at 10 years old;Speed improved most quickly in the early school-age;Search distance become shortened cross the childhood and matured at a.round 14 years old. Although the numb^r of different non-targets gave some burden on the accuracy and speed of selective attention, the ability to select targets from more complex non-targets improved across the whole childhood. As to the type of errors, there were few color confusions, but some shape confusions and more other errors. By curve regression, the results showed that the relation between the repeat errors and other errors with age were quadratic, and those errors were less in older children. Conclusions The accuracy and speed of selective attention are developed with quadratic model across childhood, and the accuracy and speed of different gender develop in different way. Boys use different strategy from girls. In simple visual selective attention task,the errors are more possible to correlate with the fine motor controlling function, and seldom with the cognition of the character of targets. The ability to inhibit the irrelevant objects is developed across childhood.Part two The switching attentionMethods Using duel-task visual search test, subjects were told to find out the special black upright ellipses and the red horizontal ellipses sequentially, with many non-targets similar to selective tasks. The correct hit", total clicks, mean time per hits, mean distance per hits and five kinds of errors were recorded by program. Those measures are compared with those of selective attention. Results The data from 555 subjects were recorded. By curve regression the results indicated that the relationship between the accuracy and the speed with age were quadratic, and showed that the accuracy, reaction time and reaction distance were developed across childhood and matured at around 14 years old. The accuracy of switching attention was different in different gender that girls had better accuracy than boys before the age of 16. Two targets and the switching gave some burden on the speed of switching attention, but the accuracy seemed no difference between selective and switchingattention. By partial correlated methods controlling the measures of selective attention, the results indicated that the ability to switch attention from previous targets to other targets are developed, the accuracy was positively correlated with age, while reaction time and distance were correlated with age negatively. As to the type of errors, it was more possible to make mistakes in the other type and switching type, the number of those errors is quadratic related with age, and those children above 10 years made less of those errors than those of younger. Across the childhood the shape confusion and the other errors declined before the age of 10. There were no significant gerder effects in all kinds of errors associated with switching attention.Conclusions The normal children after 6 years old have the excellent ability to switching attention under their controlling. The accuracy and speed of switching attention are developed across childhood and matured around 14 years old. The accuracy is different in different gender that girls are better in accuracy. In switching attention task, the frequent error are possible to correlate with the fine motor controlling function and attention shifting, in older children the ability to control their motor and attention shifting become better than the younger, and the ability to shift attention in boys is like that in girls.Part three The sustained attention and comparison with those components of attentionMethods This part held one test. Subjects were told that just those shapes with a yellow light ring was the targets, but we didn't know when the ring would arrive, they should keep their attention and waiting for it, any click in non-targets and click in targets while the ring absent were recorded as false alarm. The test longed for 10 to 20 minutes. The correct hits, the number of false alarm, mean time per hits, mean distance per hits were recorded by program. Results The data from 560 subjects were recorded. The results showed that the relationship between measures and age were quadratic. The accuracy improved, the number of false alarm and the distance were reduced across childhood, and matured around 12-14 years old. But the speed is improved across childhood until 18 years old. The number of false alarm and the reaction distance is different in different gender, girls made more mistakes than boys, but they searched less distance than boys. About comparison of those components of attention, the results showed that they were developed in different trajectories. The accuracy of selective attention matured earliest than those of other attention, but switching and sustained attentions were developed in parallel. As to the speedof those attentions they were developed in parallel. Conclusions The ability to sustain attention in normal children above 6 years old are developed under quadratic model, the accuracy is matured at the age of 12-14. The speed is matured until 18 years old. Boys and girls seem to use different strategy and have different ability to control attention. Those three components develop under different way with selective attention matured earlier than other two.Part four The executive functionMethods Using Wilding monster sorting test (WMST), which is similar to the Wisconsin card sorting test, we observed the ability to form concept, sustain set and the ability to shift attention from one set to another while solving a problem. First, showed them four monster kings with different numbers, colors, and shape characteristics. Then asked them to sort 64 monsters one by one to the king based on either of the characteristics. And the king would smile if they did correctly. After 10 correct sorting, the rule to sort was changed and we didn't let it known to subjects. There were 6 categories. The correct number, the categories they solved, the number of repeat errors, repeat corrects and errors after the set switching were recordedResults The data from 485 children were recorded. Although there were no gender differences in all measures, the executive function was developed in non-linear model. The number of correct response and categories solved improved and the number of repeat errors was reduced across childhood. By factor analysis, we extracted two main factors from the performance of WMST. The factor 1 was related with correct number, the number of categories, and conceptual level. The factor 2 was related with the number of repeat errors and perseverative errors. The results showed that factor 1 was correlated with age in quadratic model and improved across childhood. Conclysions The ability to form conception and switch attention correlated with problem solving is developed across whole childhood and seem to mature until the early stage of adulthood. It is mature later than all components of attention we studied, which seems to be related with the different mature course of different brain .regions. The performance of WMST reflects two factors, which are conceptual forming and set-shifting. The result indicated that we should evaluate the executive function from different factors.General conclusionOur study was charting the developmental trajectories of some attention components with selective, shifting, sustained attention and executive function in concept forming by a set of simple and interesting games across the age of 6 to 18. The findings suggest that age and gender related profiles across different attention components. Distinct attention and executive function are developed under distinct trajectory, selective attention is matured earliest followed by switching and sustained attention, and the executive function are immature within the age range tested. And the results demonstrate the critical importance of teasing apart components of attention and will help guide our understanding of both typical and atypical trajectories across childhood. And the results support the theory that it is important to study the normal and abnormal cognition under their developmental conditions.