Spontaneous Trait Inference Erp Study

Spontaneous trait inferences refer to the cognitive processes in which individuals infer actors'personality traits from their behaviors without intention or awareness. STIs are implicit inferential processes and relative automatic in the sense that they require little mental effort, and are difficult to suppress and hard to interfere with. It is very important in social interaction and job-hunting interviews. Traditional behavioral experiments are all limited, because these studies indeed proved STIs existing but they only explored general process of STIs, which can't be used to find the brain and neural mechinisms. Recently social cognitive neuroscience is burgeoning and enormously developing. So it is one of very popular topics to studying the neural correlates of STIs in current social cognitive neuroscience.STIs are important social cognitive processes with lots of cultural variations and individual differences. Recent evidences showed these cultural variations and individual differences are paralleling, persons in individual culture (generally, they are more idiocentric). So it is valuable to explore cultural and individual differences using brain imaging techniques. But now relevant studies are so scarce. How can cultural and individual differences influence the brain activity underlying STIs. It is very valuable to explore deeply in the future.Implicit trait theory or implicit personality theory refer to lay person understand and have basic knowledge and cognitive scheme about trait or disposition (eg. intelligence, moral characters, personality trait), which is an important topic in folk theory. Entity theorists and incremental theorists may have fundamental cognitive styles to understand others'behaviors, forming impression and evaluating others'traits.Based on relevant literatures in two areas, this present thesis selected some healthy undergraduates and graduates and used Neuroscan's ERP recording and analyzing systems to study the entity and incremental theorists'behavioral and ERP differences with many advantages in high time resolutions. Firstly I modified Dweck and his colleagues'questionnaires (1995) and used this modified tool to identified two kind of subjects. Then I borrowed and modified Bartholow's stimulus materials (2001, 2003) and finished some supplements, make it suitable to study STIs and its neural correlates in our country.Experiments include two procedures: reading task on computer screen and following sentences completion task. Systems recorded subjects'EEG while reading. After reading, they completed sentences completion task. I used SCAN 4.3 software systems to record and analyze EEG. Results indicated that entity and incremental theorists have some differences and parallels in behaviors and ERPs. The main conclusions have been drawn as follows:1. Differences of recalls of inconsistent and consistent behavioral information between entity theorists and incremental theorists in sentence completion tasks are not significant statistically. But the tendency is that incremental theorists are better than entity theorists.2. Entity theorists and incremental theorists showed more similarities at the early stage (50-250ms) and late stage (650-1250ms) during STIs.3. Entity theorists are different from incremental theorists in latencies of ERP components. About at 250-450ms, the speed of inconsistent and irrelavent behavioral information detection and evaluation are different between entity and incremental theorists, that is, entity theorists processed inconsistency and irrelevant information more slowly involve longer response inhibition and conflict monitoring. But there are no differences in trait-consistencent information processing.4. In Central and Frontal areas, about at 450-650ms after stimulus onset, the latency of P300 of incremental theorists is later than entity theorists'. This result revealed that incremental theorists evaluated and categorized person information more effortly and more longer and had a longer time to orient attention to this kind of information. Moreover, although there are some significant differences in latency of P300 between entity theorists and incremental theorists, there are important paralles in amplitues of P300 between entity theorists and incremental theorists. Only on F3 and Fz site in Frontal areas, incremental theorists paid stronger attention to person information than entity theorists.5. In Parietal areas, on P4 site, TI evoked a stronger P300 than TC. And entity theorists have larger amplitude of P300 than incremental theorists. P4 scalp site is very important for individual differences, where entity theorists and incremental theorists mainly differ in processing speed and timing in trait information detection and stimulus classification during STIs.