The Mechanism Of Sensation Seeking Trait-related Stimuli Processing By ERPs Study

Sensation seeking (SS) is the endophenotype and predisposing factor of risk takingbehavior. It is of great significance to explore the psychological and physiologicalmechanisms of SS trait for intervene in the risk taking behavior of sensation seekers(SSs). Based on previous researches, high sensation seekers（HSSs） showed strongerapproach response to intense stimuli and preferred high arousal stimuli, however, lowsensation seekers （LSSs）displayed a defensive response and were more sensitive tovalence effects. But the stimuli of previous researches were too simple and coarse,limited to the International Affective Picture System and only controlled the valenceand arousal of stimuli. No researchers regulated trait-related variables directly to studySS trait and considered the negative stimuli and other interference factors. On the basisof previous researches, this study originated the SS trait-related pictures system and weused HSS and LSS trait-related pictures respectively to study the mechanism of SStrait-related stimuli processing for the first time. Additionally, this research excluded theinterference of negative and sexual arousal stimuli. We used passive view paradigm tomeasure the ERP components in order to study the neural processing mechanisms oftrait-related stimuli. Two ERP components P3and LPP were investigated. The P3component reflects the arousal level and attentional resources allocation. The LPPcomponent is influenced by sustained attentional processing.Objective: The present study compares the different ERP components of HSSsand LSSs when the moderate-intense trait-related stimuli are presented; analysis therelationship between SS and attentional resources allocation, the ability to distinguishthe potential dangers.Methods: All the participants，answered the Sensation Seeking Scale Form Vconsisted of students from the Dalian Medical University, were divided into two groups(HSSs and LSSs). In order to enlarge the SS trait, according to their SS scores, we selected the subjects with highest and lowest scores as high or low SSs respectively.Thirty-two young adults (16female) participated in the study. The two groups differedsignificantly only in SS score with no difference in age, gender and educational level.Select90extreme sports,90leisure sports,90surreal, and90neutral pictures.Participants rated each image on levels of valence, arousal and motivation on a9pointLikert scale. Select25extreme sports,25leisure sports,25surreal, and25neutralpictures according to the rating scores as the experimental stimuli and control thevalence level of the pictures. All subjects received a passive view paradigm.Electroencephalogram (EEG) was recorded continuously by a set of32Ag/AgCIelectrodes placed. We measured the amplitude of P3at central、centro-parietal andparietal sites (Electrode sites: C3、CZ、C4、CP3, CPZ, CP4, P3, PZ, P4) and LPP atcentro-parietal site (CPZ). Subjects rated the pictures after ERP experiment. The rateddata was analyzed via t-test and ANOVAs. For ERPs data, within-group comparisonsand between-group comparisons were performed using repeated measurement analysisof variance.Results:1、There were no significant differences of P3among four stimuli. The P3components were significant different between left and right brain zones.Between-group comparisons show significant difference in P3components.2、There were significant difference of LPP among four stimuli. An interactionbetween group and stimuli style was significant. The group effect was not significant.3、The group effects were significant in valence、arousal、motivation rating data ofextreme sport pictures and neutral pictures, and in valence and arousal rating data ofleisure sport pictures.Conclusions：1、 LSSs allocated more attentional resources than HSSs tomoderate-intensity trait related stimuli.2、LSSs had a better ability to find the potential risk than HSSs.3、HSSs were dull to identify the potential risk.