Effects of Intentional Suppression of Recall of Unwanted Images in Repressors and Nonrepressors

Article excerpt

Most people experience intrusive thoughts they do not want to have, such as thoughts that are aversive and distressing and/or thoughts about traumatic events (Wegner, 1994). Individuals may often use a coping style, such as a suppression strategy, to manage or avoid unwanted thoughts. Repressor means a person who has a repressive coping style that is both an automatic and an intentional defensive strategy, a kind of avoidant way of coping with aversive events through not thinking about any painful or distressing things (Weinberger, Schwartz, & Davidson, 1979). A repressor has psychophysiological characteristics that lead to heightened autonomic arousal, despite his or her self-report of low anxiety (Derakshan & Eysenck, 1997).

The findings in studies about memory suppression in repressors have been inconsistent. In some studies, repressors have been found to suppress negative autobiographical memories (Myers & Derakshan, 2004) or unwanted thoughts (Barnier, Levin, & Maher, 2004) successfully. On the other hand, in some recent studies in which repressors have been classified as individuals who are low in anxiety and high in social desirability, no difference was found between repressors and nonrepressors in ability to suppress thoughts (Luciano & Algarabel, 2006; Myers, Vetere, & Derakshan, 2004) or that initially repressors can suppress unwanted, intrusive thoughts, but, because of rebound effects, they show maladaptive long-term consequences of such suppression (Geraerts, Merckelbach, Jelicic, & Smeets, 2006). The reason for these inconsistent results regarding thought suppression in repressors might be that in most previous studies word-based stimuli were used, even though the unwanted, intrusive thoughts comprised visual images. Therefore, further research is needed to establish whether or not repressors can successfully suppress unwanted visual images.

In the present study, we used the think/no-think (TNT) paradigm (Anderson & Green, 2001) to investigate characteristics of memory suppression. The TNT paradigm is used as a measure of the intentional suppression of unwanted memories, and it is suggested that trying not to think about information could increase subsequent memory inhibition. The TNT paradigm consists of three phases: a study phase, a TNT phase, and a cued-recall test phase. In the study phase, participants learn the cue-target pairs, such as word-word pairs (Anderson & Green, 2001; Lambert, Good, & Kirk, 2010), face-word pairs, face-picture pairs (Depue, Banich, & Curran, 2006), and word-neutral picture pairs (Peterson, 2006). In these previous studies the word or neutral picture items used yielded results that showed the TNT paradigm significantly reduced memories for to-be-suppressed items. However, suppression of memories related to aversive or traumatic events might follow different patterns compared to patterns of suppression regarding memories of words or neutral images, because aversive thoughts and trauma consist of sensory images that exposure to relevant cues could automatically trigger (Holmes, Brewin, & Hennessy, 2004). In the present study, therefore, our aim was to establish whether or not repressors experienced fewer aversive images when using the TNT paradigm than when it was not used.

Thus, we investigated differences in suppression of the recall of visual images between repressors and nonrepressors using the TNT paradigm. Our hypotheses in this study were as follows: We predicted that (a) when instructed to suppress images (no-think condition), repressors would show greater recognition reduction than would nonrepressors; (b) after watching motorbike accident video clips, repressors would show higher negative valence than would nonrepressors; and (c) repressors and nonrepressors would show no differences in degree of galvanic skin response.

Method

Participants

The participants were 87 male undergraduate students who were divided into two groups (repressor and nonrepressor) according to the distribution means of the State-Trait Anxiety Inventory-Trait (STAI-T; Spielberger, Gorsuch, & Lushene, 1970) and the Marlowe-Crowne Social Desirability Scale (MCSDS; Crowne & Marlowe, 1964). …