Abstract:

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that originated from childhood, social deficits are core symptoms of ASD. Previous studies, from a information processing perspective, proposed that a deficit in social cognitive is the cause of social impairment. However, research showed that the lack of cognitive ability was not the only reason for the social deficits of individuals with ASD, but also closely related to the social motivation deficits. Social motivation theory suggests that social motivation deficits exist in the early life of individuals with ASD and affect their subsequent development. Studying the social motivation of individuals with ASD is of great value to explain the causes of their social deficits and find the direction of intervention in the future. Therefore, this study summarizes the specific behaviors and internal and external influencing factors of social motivation deficits in individuals with ASD. In the future, it is important to comprehensively consider these factors, to strengthen the integrated research on the social motivation theory of individuals with ASD, so as to accurately understand the social motivation deficits of individuals with ASD.
Social motivation theory suggests that social motivation is a powerful driving force to guide individual’s social behavior. The theory also highlights that social behavior is mainly manifested in social orientation, social reward and social maintenance, so this paper firstly summarizes the related researches on the behavioral level of social motivation deficits in individuals with ASD, which are mainly reflected in the following three aspects: (1) The results of social orientation research show that individuals with ASD often show impaired attention to social stimuli, reduced direct gaze on the face, reduced gaze on the eyes, etc. On the one hand, this deficit is related to their abnormal face processing strategies; on the other hand, they may have difficulties in representing the intrinsic reward value of social stimuli; (2) The results of social reward research show that social reward stimulation has no significant incentive effect on individuals with ASD. They lack the ability to experience the happiness of social interaction, can't get happiness from interaction and lack the desire to help others, which is related to the abnormality of reward processing system (amygdala, ventral striatum, prefrontal cortex and other brain regions). (3) The results of social maintenance research show that individuals with ASD have few social maintenance strategies, they are not good at maintaining social relationships with others, do not actively show their own advantages, do not actively imitate others, and lack the desire and motivation to establish and maintain good relationships with others.
Finally, because the research conclusions of social motivation deficits in individual with ASD are not completely consistent, this paper comprehensively and systematically analyzes the influencing factors of social motivation deficits, and finds that it includes internal factors and external factors. The internal factors are mainly reflected in individuals' age, gender and physiological mechanism, while the external factors are mainly reflected in social communication environment, experimental stimulus materials, difficulty and nature of experimental tasks. In order to improve the credibility and effectiveness of the research on the social motivation of individuals with ASD, and fully and accurately grasp the characteristics of social motivation in individuals with ASD, in the future, it is important to study the social motivation deficits of individuals with ASD of different ages and genders, to optimize the experimental tasks, broaden the types of materials, further improve the experimental design, and to strengthen the integrated research on the social motivation theory of individuals with ASD, deeply explore the relationship among the behavioral, biological and evolutionary levels under this theory, and further analyze the relationship among the three behaviors of social motivation(social orientation, social reward and social maintenance).

Key words: autism spectrum disorder, social motivation deficits, social orientation, social reward, social maintenance