高强迫症状个体对图片刺激的注意偏向

以往强迫症注意偏向研究呈现出不一致的结果。为探索研究结果的不一致性是否由于被试取样和刺激选择所导致,当前研究改用非临床强迫症状个体作为研究对象,采用图片作为刺激来引发被试的反应和脑电波的变化。研究采用2(高强迫症状组、低强迫症状组)×3(中性图片、一般威胁图片和强迫相关图片)的混合实验设计,因变量为反应时和相关的脑电成分,结果显示:高强迫症状组较低强迫症状组对强迫相关图片表现出了更大幅度的P2波幅的变化。从而可以推断出,高强迫症状个体对强迫相关图片表现出了明显的注意偏向,其成分为注意脱困,主要发生在早期自动化加工阶段。

Attentional Bias of Individuals with High Obsessive-Compulsive Symptoms to Pictures Stimuli

Obsessive-Compulsive Disorder(OCD)affected people’s life,study and work seriously.Some researches on the attentional bias of OCD individuals were done to reveal the mental and physical mechanism of this disorder.Results of these researches were not consistent.Several researches provided some evidence that compared with other stimuli,the obsessive-compulsive stimuli would draw the attention of OCD patients more than healthy people,but no similar results were obtained by other researches.Perhaps research material and participants caused these contradictory results,i.e.,word material was used for stimuli and OCD patients were selected to participate in these researches.This research attempts to use pictures as stimuli and to select non-clinical OCD university students to take part in experiments to explore the attentional bias of OCD individuals.One hundred and ninety five volunteer undergraduates and postgraduates from Gannan Normal University were recruited for this research.The obsessive-compulsive symptoms were rated by The Padua Inventory Washington State University Revised(PI-WSUR).High and low obsessive-compulsive symptom groups each include 25 individuals selected to participate in the experiments.The PI-WSUR score between the high obsessive-compulsive(HOC)group and the low obsessive-compulsive(LOC)one had a significant difference.Two mixed factors were designed in the experiments.Group is between-subject factor including HOC and LOC levels,and picture category is within-subject factor including neutral,threatening and obsessive-compulsive picture levels.The dependent variables involve in response times and event-related potentials.The experimental program was written by E-Prime2.0 software according to the task paradigm of point detection.Results of the behavioral experiment show that the main effect of group was not significant,the main effect of picture category is not significant,and the interaction effect between group and picture category is not significant.In the ERPs experiment,20 LOC group data and 22 HOC group data were screened for the following analysis.P1 and P2 amplitudes were observed.For P1 amplitude,only the main effect of picture category is significant,compared with neutral picture,threatening and obsessive-compulsive pictures evoked enhanced P1 amplitude.For P2 amplitude,(a)the main effect of the group was significant,relative to LOC group,HOC group had a enhanced amplitude,(b)the main effect of picture category is significant,obsessive-compulsive pictures can evoke a more enhanced amplitude than neutral and threatening pictures,and threatening pictures can evoke a more enhanced amplitude than neutral pictures,(c)the interaction effect between group and picture category is also significant,obsessive-compulsive pictures can evoke a more enhanced amplitude for HOC group than for LOC group,but the two other pictures cannot lead to the different results for these two groups.The experimental results implied that the attentional bias of high obsessive-compulsive individuals to obsessive-related pictures can not be found in the behavioral experiments,but can be discovered by ERPs changes.This attentional bias occurs in the early stage of automated processing,and is manifested as a phenomenon of difficulty in disengaging attention away from threat.