Department of Psychology, University of Konstanz, Germany.
Psychol Med. 2012 Jun;42(6):1283-91. doi: 10.1017/S0033291711002273. Epub 2011 Oct 20.
Traumatized individuals and particularly post-traumatic stress disorder (PTSD) patients are characterized by memory disturbances that suggest altered memory control. The present study investigated the issue using an item method, directed forgetting (DF) paradigm in 51 civil war victims in Uganda. All participants had been exposed to severe traumatic stress and 26 additionally suffered from PTSD.
In an item cued, DF paradigm photographs were presented, each followed by an instruction to either remember or forget it. A recognition test for all initially presented photographs and thematically similar distracters followed. DF patterns were compared between the non-PTSD and the PTSD groups. Post-experimental ratings of picture valence and arousal were collected and correlated with DF.
Results revealed DF, that is, reduced recognition for 'to-be-forgotten' items in the non-PTSD but not in the PTSD group. Moreover, in the non-PTSD, but not in the PTSD group, false alarms were reduced for 'to-be-remembered' items. Finally, DF was reduced in those participants who rated the pictures as more arousing, the PTSD group giving, on average, higher arousal ratings.
Data indicate that DF is reduced in PTSD and that the reduction is related to stimulus arousal. Furthermore, individuals with PTSD are characterized by a more global encoding style than individuals without PTSD, reflected in a higher false alarm rate. In sum, traumatized individuals with (but not without) PTSD are impaired in their ability to selectively control episodic memory encoding. This impairment may contribute to clinical features of the disorder such as intrusions and flashbacks.
创伤个体，尤其是创伤后应激障碍（PTSD）患者，其记忆障碍特征表明记忆控制发生改变。本研究采用项目方法，即直接遗忘（DF）范式，在乌干达的 51 名内战创伤患者中对此进行了研究。所有参与者均经历过严重的创伤性应激，其中 26 人还患有 PTSD。
在项目提示的 DF 范式中呈现照片，随后会出现一个记住或忘记的指令。接下来是对所有最初呈现的照片和主题相似的干扰项进行识别测试。比较非 PTSD 组和 PTSD 组之间的 DF 模式。实验后收集照片效价和唤醒的评分，并与 DF 相关联。
结果显示，在非 PTSD 组中存在 DF，即“待遗忘”项目的识别率降低，但在 PTSD 组中则没有。此外，在非 PTSD 组中，“待记忆”项目的错误警报减少，但在 PTSD 组中则没有。最后，那些对图片评价为更令人兴奋的参与者的 DF 减少，而 PTSD 组平均给出的唤醒评分更高。
数据表明，DF 在 PTSD 中减少，并且这种减少与刺激唤醒有关。此外，与非 PTSD 个体相比，PTSD 个体的编码风格更为整体，表现为更高的错误警报率。总之，患有（而非没有）PTSD 的创伤个体在选择性控制情景记忆编码的能力上存在障碍。这种障碍可能导致该障碍的临床特征，如闯入和闪回。
