Clinical and Health Psychology, Utrecht University, PO Box 80140, 3508 TC, Utrecht, The Netherlands.
J Behav Ther Exp Psychiatry. 2011 Mar;42(1):32-7. doi: 10.1016/j.jbtep.2010.09.004. Epub 2010 Sep 21.
Eye movements during exposure to distressing mental images reduce their vividness and emotional intensity, which may be due to both tasks competing for working memory (WM) resources. WM theory predicts an inverted U-shaped relationship between degree of taxing and beneficial effects: greater taxing of WM will more greatly reduce vividness/emotionality, but extremely taxing tasks prevent holding the image in mind, thereby reducing benefits. This study examined whether mental arithmetic (subtraction) tasks during visual imagery reduce image vividness/emotionality ratings, and taxing WM and reduced vividness/emotionality show the predicted quadratic relationship. A non-clinical sample retrieved a distressing image of the Queen's Day tragedy (which occurred 1-3 months earlier in the Netherlands), and rated it for vividness and emotionality. Participants were assigned to one of four conditions: exposure alone or exposure with concurrent 'simple' subtraction, 'intermediate' subtraction, or 'complex' subtraction. Afterwards, vividness and emotionality were rated again. A reaction time task showed that the subtraction tasks increasingly taxed WM. Consistent with WM theory, exposure with subtraction reduced image vividness and emotionality compared to exposure alone. The expected inverse U-curve relationship was found for emotionality, but not for vividness: simple or intermediate subtraction had more beneficial effects than no dual-task or complex subtraction. Clinical implications are discussed.
在观看令人痛苦的心理图像时，眼球运动可以降低图像的逼真度和情绪强度，这可能是因为这两个任务都在争夺工作记忆（WM）资源。WM 理论预测，任务的难度与有益效果之间存在着倒 U 型关系：WM 的负担越大，降低图像逼真度/情绪性的效果就越明显，但负担过重的任务会阻止图像在脑海中保持，从而减少益处。本研究考察了在视觉想象过程中进行心算（减法）任务是否会降低图像的逼真度/情绪性评分，以及 WM 的负担和降低的逼真度/情绪性是否表现出预测的二次关系。一个非临床样本回忆了荷兰女王日悲剧（1-3 个月前在荷兰发生）的一幅令人痛苦的图像，并对其逼真度和情绪性进行了评分。参与者被分配到以下四种条件之一：单独暴露或同时进行“简单”减法、“中等”减法或“复杂”减法的暴露。之后，再次对逼真度和情绪性进行评分。一项反应时间任务表明，减法任务对 WM 的负担越来越大。与 WM 理论一致，与单独暴露相比，暴露加减法会降低图像的逼真度和情绪性。对于情绪性，发现了预期的倒 U 型关系，但对于逼真度没有发现这种关系：简单或中等减法比没有双重任务或复杂减法有更有益的效果。讨论了临床意义。
