| Theory of mind (ToM) refers to the ability to understand other people's mental states and to infer their behaviors. Executive function (EF) refers to a set of higher order cognitive skills that are responsible for conscious and effortful control of thought and behavior. Both ToM and EF are important for human development and social life. According to previous studies, EF influence the development of ToM and the on-line processing by constructing the conception of ToM and inhibiting the prepotent response. However, so far the detailed mechanism of the influence from EF to ToM has not been clear. The present studies focused on such mechanism, and there were four studies.The first study adopted three types of executive function (EF) tasks which came from Hala's study, and four (TOM) questions to examine the relation between TOM and EF in 114 Chinese children at 3 years and 6 years. It was found that the ability to attribute ignorance and the EF matured at about four years, and the false belief (FB) understanding ability became mature at about five years. That the development of EF was earlier than FB understanding supported the hypothesis of Russell that EF was the precondition of FB understanding ability. The relation between TOM and EF was changed according to the different developmental stages of TOM and EF, or the different components or dimension. On the one hand, at the elementary developing stage of FB understanding ability, the relation between it and working memory EF was significant; at the fast developing stage of FB understanding ability, the focus of the relation was transferred to the relation between it and EF combined with working memory and inhibitory control gradually; at the developed stage of FB understanding ability, it was significantly related to the combined EF. On the other hand, the ability to attribute ignorance was always significantly related to the combined EF.On the basis of Study 1, study 2 investigated how EF influenced the development of children's ToM. According to documents, there might be two ways by which EF influenced ToM. The expression account implicates poor EF as the cause of young children's failure to express their false belief conception that they already have acquired (Russell,1996; Moses,2001). The emergence account holds that EF might actually take part in constructing false belief conception (Russell,1996; Moses,2001). To investigate the controversy involving the relationship between false belief (FB) and executive function (EF), four components in an unexpected location FB task were separated by designing a conflicting true belief task and adopting standard and diverse belief tasks. The four components were'acting according to belief,'differentiating another's belief,'inhibiting reality bias', and'FB understanding'. Children 3 to 6 years old (N=105) partook in these belief tasks and in two conflict control tasks. Children's difficulty in the FB task reflected a lack of FB conception, rather than inhibition of reality. Only the location FB task was significantly related to the EF task, after ruling out age and PPVT scores. Overall, these results supported the emergence over the expression account.Next, in Study 3 there were three experiments to explore children's performance on fasle belief tasks with different executive demandings. In the first experiment, the inhibiting demands were manipulated in four conditions, which are the standard condition, the disappeared condition, the taken away condition and the uncertain condition. The experiment 1 was purposed to investigate which condition could significantly improve 4-and 5-year-old children's performance compared with the standard condition. The second experiment replicated the produce of experiment 1 and was purposed to investigate whether 3-year-old children's performance would increase in these conditions. In experiment 3, two new conditions were designed to investigate whether 4-and 5-year-old children's improving performance in disappeared condition in experiment 1 was because of the effective manipulation or was due to their random guess. The results was as following, experiment 1 and 2 showed that compared to the standard condition, the disappeared and taken-away condition could significantly improve 4-and 5-year-old children's performance; anywhere condition improved 5-year-old children's performance; while none of the manipulations could improve 3-year-old children's performance. In the experiment 3, it was showed that the at least some of children's improvement in disappeared condition was due to their random guess. According to the results in all the experiments, it was implied that both conceptual change and early competence was important for children's successfully inferring FB.On the basis of the Study 1 to 3, it could be implied that EF influence children's development through double ways. On the one hand, EF takes part in the on-line processing of ToM; and on the other hand, EF helps children with constructing false belief conception. However for adults, they have good false belief conception, then what is the mechanis that EF influences ToM processing. Study 4 investigated the neural course of different ToM processing with variable EF demandings. In experiment 1, event-related potentials (ERPs) elicited by FB reasoning in the standard unexpected location FB tasks were compared with those in the adapted unexpected location FB tasks. In both kinds of tasks, participants firstly read the stories depicting by four pictures and then inferred the puppet's FB. The story was following, a puppet put a ball at location A and then left; after his leaving, ball was carried to location B in the standard condition; in the adapted condition, the ball was carried to certain place where the participants did not know. After the stories, participants were asked FB question (where will the puppet think the ball is after he come back). To infer FB, participants need inhibit their own knowledge about the ball's current location in the standard condition; while they need not in the adapted condition. Results showed that participants'average response time in the standard condition was significantly longer than that in the adapted condition; the ERP component elicited by FB reasoning in the standard tasks was more positive at 470-520ms than that in the adapted tasks; and this late positive component (LPC) divergence was located in the left middle frontal gyrus (LMFG). The results confirm the on-line influence of inhibitory control to FB reasoning, and imply that inhibition process in FB reasoning is earlier than the operation of FB conception.Experiment 2 adopted true belief tasks, besides standard and adapted false belief tasks and investigated the neural correlates of three kinds of belief reasoning. It was found that the ERPs elicited by them were significantly different at four epochs. Firstly, N170 elicited by standard and FB was more negative than that elicited by TB reasoning at the bilateral partial-occipital electrodes; then from 350-400ms post-stimulus, both types of FB reasoning elicited the more positive P300 than TB reasoning at central-partial cortex; next from 500-550ms, TB and standard FB reasoning elicited the more negative potentials than adapted FB reasoning at frontal-central electrodes; finally, the late slow wave in FB belief tasks were more positive than that in TB tasks on the left hemisphere. Experiment 2 declared once more that the late positive components might be important for EF processing in belief reasoning. However, this experiment implied that the role of EF in belief reasoning was not inhibiting prepotent responses as the previous studies proposed, but was cognitive selection.Taken together, these four studies showed that (1) the relation between ToM and EF was variable for the different components and developmental stages; (2) EF influenced ToM by two ways, EF took part in children and adults'on-line ToM processing and for children only EF helped children with constructing false belief concept; (3) late positive components might related to executive selection in ToM processmg.
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