A Comparative Behavioral And Event-Related Potentials Studies On Preschoolers’ Expression Cognition Of Cartoon Face And Real Face

The ability of facial expressions recognition, which often plays a remarkable role in daily communication, is the highlight of emotional psychology and cognitive neuroscience studies in recent years. Cartoon faces, as an important part of children’s daily life, are exercising an invisible, formative influence on children’s cognitive and social development. To explore the differences in time courses of brain responses and in accuracy rates of behavioural reactions, six-year-old children were given facial expression recognition and labeling tasks in behavioural study and large numbers of other six-year-old children were given explicit and implicit facial expression processing tasks during ERP recording with10kinds of stimuli,5kinds of expression (Happiness, Neutral, Sadness, Fearful and Angry)×2face type (Cartoon and Real). The conclusions are as follows:(1) During the facial expression recognition and labeling tasks, cartoon faces had more advantage in expression cognition than real faces.6-year-old children were mature in facial expression cognition but were slightly better on the facial expression recognition than facial expression labeling, expression of fearful in especial. Different facial expressions were learnt as an order from expression of happiness to sadness in children. In addition, compared with boy, girls did better on expression recognition of sadness.(2) During implicit facial expression processing tasks (Gender Discrimination&Target Stimuli), the N170was sensitive to both cartoon and real faces; real faces had an advantage in intensity over cartoon faces at the early encoding stage during the gender discrimination tasks. But cartoon faces had a significant advantage in the late processing also during the gender discrimination task, which reflected that children paid more attention to cartoon faces as products of art and invested more mental resources.In both tasks, N170evoked by different facial expressions had no significant differences in latency and amplitude, indicating that face specific component N170was independent of facial expression of emotion; but P2evoked by negative facial expression was significantly larger than neutral, and expression of sadness got the largest. During the gender discrimination task, N2evoked by expression of sadness and LPC evoked by expression of neutral were significantly larger than other expressions of real faces. Hemispheric dominance was founded in N170and central processing advantage was founded in LPC. No gender differences were founded. During implicit expression processing, the results may be affected by different tasks.(3) During explicit facial expression processing tasks (Expression Judgement&Expression Matching), the N170was sensitive to both cartoon and real faces; real faces had an advantage in intensity over cartoon faces at the early encoding stage. But cartoon faces had a significant advantage in the late processing also during the gender discrimination task, which reflected that children paid more attention to cartoon faces as products of art and invested more mental resources.Because there is no separation of each expression (Happiness, Neutral, Sadness, Fearful and Angry) in both tasks, expression effect was not concluded. Hemispheric dominance was not founded in N170but central processing advantage was founded in LPC. No gender differences were founded. Combining the results of two explicit expression processing tasks, although the difficulty of the task is greater in expression matching task, but the result was similar. It suggested that during explicit expression processing, the results may not affected by the difficulty of tasks.In conclusion, our findings confirm the significant difference between cartoon and real facial expressions cognition and its neural mechanisms. It demonstrated that:(1) Children’s cognitive ability of cartoon facial expression is better than real faces, sadness, fear and neutral expressions in special, which is due to the exaggerated expressions and simplified features on cartoon faces that in line with the children’s development on facial cognition;(2)The neural mechanisms between cartoon and real faces is significantly different, corresponding to the Bruce&Young’s face processing model; the intensity of real faces is larger than cartoon faces at early encoding stage on6-year-old children suggesting the higher degree of automotive processing on real faces; the intensity of cartoon faces is larger than real faces at late features processing stage suggesting that cartoon faces are more attractive for young children and children put more attention resources;(3) under the implicit processing tasks, the difference of ERP components evoked by different expressions between real and cartoon faces is significant, indicating that facial expression of children processing is automated;(4)(4)6-year-old children’s implicit and explicit processing of facial expression is not significantly different at the early coding stage, and is significantly different at late features processing stage, suggesting that expressions the depth of explicit processing is higher than the implicit processing;(5) behavioral and ERP experiments showed that it is imbalance on the development of6-year-old children’s ability to identify different expressions; according to the results of this study, using cartoon faces as learning materials of facial expressions, will promote face cognitive ability of children.