عوامل آلکسیتیمیا و اجرای حافظه برای کلمات خنثی و هیجانی

Alexithymia is a multifaceted personality construct, which includes difficulties in identifying and expressing feelings and an externally-oriented cognitive style. We investigated the effects of alexithymia and its subscales on recall and recognition rates for neutral, joy, disgust and anger words. We found that the alexithymia-factor difficulties identifying feelings was negatively associated with memory performance for emotion words whereas a positive association was found between the alexithymia factor externally-oriented cognitive style and recognition rates for all words (emotional and neutral). The deficit for difficulties identifying feelings was particularly strong for remember responses. Such a deficit in the ability to consciously recognize emotional concepts could be related to the observed difficulties in regulating intense feelings found in high alexithymia scorers.

Alexithymia is a multifaceted construct that includes difficulties in identifying and expressing feelings, a reduced capacity to engage in fantasy and other imaginal activities, and a stimulus-bound, externally-oriented cognitive style (Taylor, Bagby, & Parker, 1997). Empirical findings have shown that high alexithymia scorers report lower intensity of emotional responses at the cognitive/experiential level to an emotional visual stimulus (e.g., lower reports of emotional appraisals; Luminet, Rime, Bagby, & Taylor, 2004). Some studies have demonstrated that participants scoring high in alexithymia show deficits in anger processing (Vermeulen et al., 2008 and Vermeulen et al., 2006). At a neurophysiological level, some Event-Related Potential (ERP) findings have revealed that high alexithymia scorers can correctly perceive and categorize aversive pictures but that they need more cognitive resources to do so (Franz, Schaefer, Schneider, Sitte, & Bachor, 2004). For Taylor et al. (1997), high alexithymia scorers are often unable to link feelings with memories. Therefore, understanding how alexithymia moderates memory performances is an important step to better understand how this construct disrupts emotional processing. Some research has started to investigate memory performance in alexithymia but contrasting findings have been obtained. Indeed, whereas some studies have found a deficit in memory for emotional stimuli in alexithymia (i.e., Luminet et al., 2006, Montreuil and Pedinielli, 1995 and Suslow et al., 2003), other studies have failed to find an effect of alexithymia (Jacob and Hautekeete, 1998 and Lundh et al., 2002, Study 1). It has been proposed that some methodological differences and shortcomings could account for such contrasting results (Luminet et al., 2006). For instance, Lundh and colleagues (2002) studied episodic memory by measuring response latencies whereas Luminet et al. (2006) studied semantic memory by scoring recall rates in a depth-of-processing manipulation. Importantly, an alternative explanation was proposed for the results of Luminet et al. (2006). The authors posited that higher alexithymia scorers rated emotion words as less emotional than lower alexithymia scorers. Therefore, the way people initially appraised the words could explain the poorer performance of high alexithymia scorers. Also in Luminet et al. (2006), there was a floor effect in the shallow condition (4.6% of recalled words). Finally, previous studies only compared neutral to positive and negative material without paying attention to discrete emotions and particularly anger. Therefore, further studies are needed in order to assess such memory performance in alexithymia. The main aim of the present study is to investigate whether the memory for different types of emotion is moderated by alexithymia level. We decided to introduce four different discrete emotional states such as neutral, joy, disgust and anger. As was done in Luminet et al. (2006), we used the level of processing (LOP) paradigm (Craik & Tulving, 1975). In the LOP paradigm, stimuli are processed either in a shallow way that focuses on the physical features of the stimuli (e.g., size of font), or in a deep way in which the meaning of the stimuli must be processed to adequately complete the task (e.g., adequacy of a word in a sentence). In order to avoid a floor effect, we decided to use another shallow condition which enhanced memory performance (Craik & Tulving, 1975, Experiment 5). We also decided to use a deep task in which participants had to evaluate the emotional meaning of the words (Niedenthal, Winkielman, Mondillon, & Vermeulen, in press). This procedure ought to be better adapted to alexithymia since it forces participants to access emotional meaning of the words in order to answer. Moreover, we decided to use the Remember/Know procedure which is proposed to operationally define autonoetic (self-knowing) and noetic (knowing) consciousness during retrieval of information (Gardiner, 1988 and Tulving, 1985). The “Know” responses, produced by noetic consciousness, reflect this feeling of knowing that a stimulus has been presented before. The “Remember” responses indicate that participants could consciously recollect some aspects of what was experienced at the time the stimuli were presented (e.g., what one was thinking at the time of encoding) (Gardiner, 1988). We hypothesized that participants would recall and recognize more words in the deep (semantic) vs. shallow (perceptual) processing condition (Craik & Tulving, 1975). It was also predicted that the participants would recall and recognize more emotion words than neutral words (e.g., Ferré, 2003). Based on previous findings (e.g., Luminet et al., 2006), we hypothesized that alexithymia would moderate the overall retention of emotional words but not of neutral words. Moreover, based on previous findings showing a deficit in anger processing in alexithymia (e.g., Vermeulen et al., 2006 and Vermeulen et al., 2008), we expected a stronger moderating impact of alexithymia on memory performance for anger words. We also chose to contrast anger words with positive emotion words (i.e., joy) and another high arousal negative emotion (i.e., disgust). Regarding the differential effects of the three factors, as proposed by Suslow et al. (2003), we suggest that the factor ‘‘difficulty in identifying feelings” (DIF) and the factor ‘‘difficulty in describing feelings” (DDF) would be associated with poor memory performance for emotional words. Inversely, the cognitive factor “externally-oriented cognitive style” (EOT) of alexithymia would be less or not at all related to memory performance for emotional words. Based on Luminet et al. (2006), we hypothesize that these effects should be particularly marked for the “Remember” but not for the know level of consciousness.