PTSD青少年对威胁图片注意偏向的时程特点及习惯化倾向

探讨创伤后应激障碍(post-traumatic stress disorder,PTSD)青少年(n=20)与创伤控制组(n=20)对威胁图片注意偏向的时间进程特点以及习惯化倾向.在线索提示任务中,图片的呈现时间为100ms、500ms和1250ms.研究表明:(1)在时间进程上,当图片呈现100ms时,创伤控制组对地震图存在注意警觉;当呈现时间为500ms时,两组被试对负性图和地震图存在注意回避;当呈现时间为1250ms时,PTSD组对负性图仍存在注意回避、对地震图的注意偏向消失,创伤控制组对负性图和地震图的注意偏向均消失.(2)在习惯化倾向上,当第六次呈现威胁图片时,PTSD组对负性图和地震图的注意偏向消失,而创伤控制组对负性图和地震图的注意回避仍未消失.

The temporal course and habituation tendency of the attention bias to the threaten stimulus in the adolescents with post-traumatic stress disorder(PTSD)

Since Wenchuan earthquake,researchers paid much attention to individuals with posttraumatic stress disorder(PTSD) in China.And attentional bias has been widely demonstrated in PTSD individuals.However,few studies discussed the change of the bias in PTSD adolescents.In two experiments of present study,we intended to examine the time-course and the habituation in attentional bias to the threatening pictures in 40 children who had experienced the Wenchuan earthquake and counterpart without PTSD as control group by the exogenous cueing paradigm.Threat value,presentation duration and frequency of the cues were systematically varied.Results suggest that:(1) when the presentation duration was 100 ms,the trauma control group showed facilitated attentional engagement to the earthquake related pictures.When the presentation duration was 500 ms,all participants showed avoidance of attention to the earthquake related and negative pictures.When the presentation duration was 1250 ms,PTSD group still showed avoidance of attention to negative pictures,but avoidance to earthquake related pictures disappeared;avoidance of attention in trauma control group disappeared.(2) when the cue presentation frequency was six times(presentation duration was 500 ms),the attentional bias to negative and earthquake related pictures disappeared in PTSD group,while that still existed in control group.The present results support that the cycle of "alert-avoid-difficulties in disengaging" existing in the attentional bias of PTSD adolescents to the threatening information,while their attentional bias will be eliminated with the increase of the presentation frequency.Besides,the control group’s attentional bias to threatening stimulus is easier to eliminate with longer present time.