An ERP Study In Facial Information Processing Of Different Cognitive Style Individuals

There has been numerous researches about cognitive style since it was put forward.Of the cognitive styles that have been identified, field dependence-independence has received the greatest research attention over the years. As a kind of relatively steady individual differences, cognitive style is regarded as an important personality dimension. According to the prevenient behavioral studies about cognitive style, the judgement and attitude of the field dependent individuals tend to be influenced by social cues at the outside. In other words, the field dependent individuals would like to refer to information that others offer with. While the field dependent individuals pay mort attentions to the information that related with the task.Face is the most popular thing in our daily lives. We can get lots of very important social information from the face recognition. Now, one of the hotspot of face recognition research is the research to face-specific components and structural encoding. In the research of face identification, investigators adopt manipulating face-specific components and structural information, the experimental manipulation to face-specific components is to change the attributes of the face components or replace them. To structural information, the manipulation is to invert the face and change the spatial distance of the face components. As a kind of objective and effective research approach, the technique of event-related potential(ERP) has been used widely in many aspects with the development of neuroelectrophysiology and computer technology since the 60s of the 20th century. The event-related potential(ERP) is a neural signal that reflects coordinated neural network activity. In the field of psychology, ERP method is a available tool to study the cognitive processing( perception, attention, memory etc.) and cognitive function. Already there has been ERP researches about field dependent-independent cognitive style which suggest the existence of cerebral electrophysiological differences in working memory and inhibition processes between different cognitive style individuals. Therefore, we try to realize the differences of cognitive styles in facial information processing with ERP technique, if the differences between the field dependent-independent individuals really exist, we try to understand the neurophysiological mechanism inside our brains.The study included two experiments: Experiment 1 let the subject distinguish the sex of the face. Its design was a 2(cognitive style: FD;FI)×2(locatin of face: upright, inverted) mixed factorial that included the between-subjects variables of FDI and effectiveness of the the within-subject variables of location of face. Experiment 2 uses the study-test paradigm and asks the subject to judge the familiarity of the separate face-specific components, whose design was a 2(cognitive style: FD;FI)×2(familiarity: familiar , unfamiliar)×3 ( face-specific components: eye, nose, mouse)mixed factorial that included the between-subjects variables of FDI and the within-subject variables of the others. The EEG was recorded by the 32 channel quik-cap and amplified by the SynAmps equipment produced by Neuroscan company. The recording frequency band was 0.05~100Hz with an A/D rate 1000Hz, all the data was stored for off-line analysis.The main results in the study were:1. There were great statistically differences by N170 amplitude between two groups in the structural information processing experiment. The amplitude in FI group was higher than FD, while no statistically significant difference was found in the latency of N170. Moreover, the amplitude in inverted face of N170 is much higher than upright face.2. The interaction between cognitive style and face location is significant. The difference of the average amplitude of LPC in upright and inverted face between FI and FD group is not significant through the simple effect test, but reaches significant in FI individuals while the opposite result in FD individuals.3. In the face-specific components experiment, there were significant differences between field-independent(FI) and field-dependent(FD) subjects in the amplitude of N170, While the differences in the latency of N170 is not significant. And the amplitude of N170 is not effected by the familiarity of the face.4. In the face-specific components experiment, the difference between field- independent(FI) and field-dependent(FD) subjects in the average amplitude of late positive component LPC is not significant, it is not significant in familiar face-specific components and unfamiliar face-specific components for field-dependent subjects.