Abstract:

Previous studies have found that the behavioral patterns of individuals with autistic traits are similar to those of individuals with autism spectrum disorders (ASD). That is, individuals with autistic traits show the impairment of empathy in daily life, but the severity of such impairment is not enough to meet the clinical diagnostic criteria for ASD. The similar behaviors between the two mean that studying individuals with autistic traits can help us understand the empathy characteristics of ASD. At present, the results of studies on the empathy for pain of autistic individuals are not consistent. It is possible that attention cues and specific face processing affect their empathy processing.
Therefore, in this study, pictures of painful faces were used as stimulus materials, and the event-related potentials (ERP) technique was adopted to explore the effect of attention cues on the pain empathy processing in autistic individuals. The study randomly selected 30 healthy undergraduates (15 males) as the autistic trait group, and 30 healthy undergraduates (16 males) as the control group. The experiment, based on three-factor mixed design (2×2×2), included two tasks: 1) Pain judgment task: The subjects were required to judge whether there was pain in the pictures of the painful faces (with a needle in the cheek) and the pictures of the non-painful faces (touched gently with a cotton swab), where the subjects' attention was directed to the pain cues. 2) Attractiveness judgment task: The subjects were required to judge whether the faces were attractive or unattractive, where the subjects' attention did not point to the pain cues. EEG during the observation of pictures under different experiment tasks was recorded by a 64-channel amplifier using a standard 10-20 system (Brain Products).
The ERP results revealed that the attention cues would influence the late cognitive processing stage component P3, but not the early automatic component. Compared with the control group, the autistic trait group induced a larger P3 amplitude by the painful face pictures in the attractiveness judgment task; however, in the pain judgment task, there was no significant difference between the two groups.
This suggests that top-down attention to visual pain cues may modulate the late processing of pain empathy in autistic individuals, as manifested in the following fact: When autistic individuals pay attention to pain cues, they have similar empathic neural responses to the control group; when they do not pay attention to pain cues, they process other people's painful faces to a higher degree. This result also suggests that autistic individuals may avoid other people's face information, and provides evidence for the empathy deficit of autistic individuals. This conclusion is helpful for understanding the cognitive processing characteristics and influencing factors of pain empathy in ASD.

Key words: empathy, empathy for pain, autism spectrum disorders (ASD), autistic traits, event related potentials (ERP)