نقش اضطراب خصلتی در شناخت عبارات عاطفی چهره

Previous work has suggested that elevated levels of trait anxiety are associated with an increased ability to accurately recognize the facial expression of fear. However, to date, recognition has only been assessed after viewing periods of 10 s, despite the fact that the process of emotion recognition from faces typically takes a fraction of this time. The current study required participants with either high or low levels of non-clinical trait anxiety to make speeded emotional classification judgments to a series of facial expressions drawn from seven emotional categories. Following previous work it was predicted that recognition of fearful facial expressions would be more accurate in the high-trait anxious group compared with the low-trait anxious group. However, contrary to this prediction, no anxiety-related differences in emotion perception were observed across all seven emotions. This suggests that anxiety does not influence the perception of fear as has been previously proposed.

The ability to interpret correctly the emotional facial expressions of others is a skill fundamental to successful human interaction. It has been suggested that emotional facial expressions evolved as an external representation of internal emotional states as a means for swift communication of these states between individuals (Blair, 2003). Darwin (1872) believed that facial expressions are an innate and universal component of non-verbal communication. In support of this view, Ekman (1972) has shown comparable patterns of production and recognition of emotional facial expressions across different cultures. Atypical processing of emotional facial expressions is thought to be a feature of some neuropsychological and clinical disorders. For example, recognition of disgust is impaired in Huntington's disease (Gray, Young, Barker, Curtis, & Gibson, 1997). Furthermore, recognition of anger is thought to be impaired in patients with clinical depression (Mendlewicz, Linkowski, Bazelmans, & Philippot, 2005; although see Persad and Polivy (1993) who present evidence for a general processing deficit of emotional facial expressions in depression). In contrast to these processing deficits associated with some conditions, recent evidence has emerged suggesting that heightened (but non-clinical) levels of trait anxiety are associated with an ability to more accurately recognize fearful facial expressions (Surcinelli, Codispoti, Montebarocci, Rossi, & Baldaro, 2006) relative to lower levels of trait anxiety. The current paper explores the relationship between recognition of emotional facial expressions and individual differences in trait anxiety. Early cognitive theories of emotional disorders (Beck, 1976 and Bower, 1981) predict that anxiety should be associated with biases favoring the processing of emotional stimuli across all domains of information processing (e.g., attention, memory, etc.). However, despite attempts to find such an information processing bias in memory (e.g., Mogg, Mathews, & Weinman, 1987) there currently exists no consensus on the relationship between memory for emotional stimuli and anxiety (Richards et al., 2002). Some studies have shown that high levels of trait anxiety are associated with improved retrieval of threat-related information compared with neutral information (e.g., Claeys, 1989; Eysenck & Byrne, 1994), while others have found no effects (e.g., Foa, McNally, & Murdock, 1989; Lang & Craske, 1997). Contrary to this, there is a large body of evidence suggesting anxiety is associated with a bias in attentional processing; a bias that favors the processing of threat-related information (e.g., Eysenck, 1992; Mathews & Mackintosh, 1998; see Bar-Haim, Lamy, Pergamin, Bakermans-Kranenburg, & van Ijzendoorn, 2007 for a recent meta-analysis). Furthermore, it has been argued that this bias in attentional processing towards threat stimuli is the most important cognitive factor in the etiology and maintenance of anxiety (Mogg & Bradley, 1998). While such attentional bias is the most documented of information processing biases in anxiety (Mathews, Mackintosh, & Fulcher, 1997) it is not the only reported. Anxiety is also thought to influence the interpretation of ambiguous stimuli. For example, when presented with threat/neutral homophones and asked to make a classification judgment, high-anxious individuals are more likely than low-anxious individuals to interpret the word as threat-related rather than neutral (Mathews, Richards, & Eysenck, 1989). Evidence for such anxiety-related biases in attention and interpretation are also displayed in relation to the processing of emotional facial expressions. In the dot-probe task for example,1 individuals with high levels of anxiety demonstrate attentional biases towards the location of both angry (e.g., Bradley, Mogg, Falla, & Hamilton, 1998) and fearful (Fox, 2002) expressions relative to expressions that are happy or neutral.2 Furthermore, in an interpretation task, Richards et al. (2002) presented ambiguous emotional facial expressions that had been constructed by morphing together two different emotional expressions (e.g., fear and surprise). When these ambiguous expressions were presented, high-anxious participants were more likely than low-anxious participants to identify them as fearful. Taken together, these studies demonstrate that at least some aspects of the processing of threat-related emotional facial expressions (i.e., allocation of attention; interpretation of ambiguous stimuli) are susceptible to individual differences in anxiety. However, even in the study of attention there have been mixed findings in terms of how anxiety influences the way attentional resources are allocated to emotional facial expressions. Rossignol, Phillippot, Douilliez, Crommelinck, and Campanella (2005) gave participants a visual oddball task where they had to detect a discrepant fearful or happy face amongst a series of neutral faces. Participants who rated highly on self-report measures of anxiety were quicker to identify discrepant faces than non-anxious participants. However, fearful faces were detected just as quickly as happy faces. Similarly, Fox et al. (2000) gave participants a visual search task in which they had to search for either a positive or negative schematic face amongst sets of distracter faces. They reported that negative faces were found more efficiently than positive faces but that this effect was not modulated by participants’ level of self-reported anxiety. Thus, some tasks demonstrate anxiety-related differences in the way threat-related emotional facial expressions are processed while others do not, suggesting anxiety may only be influencing certain aspects of the way attention is allocated (Mathews & Mackintosh, 1998). More recently, and importantly for purposes of the present study, research has examined how emotion recognition (i.e., the ability to classify different emotional facial expressions as belonging to different discrete categories) might be influenced by anxiety. Surcinelli et al. (2006) gave a non-clinical sample of high- and low-trait anxious participants an emotion recognition task. Participants were presented with a series of images of emotional facial expressions, each for 10 s. Once each image disappeared from the screen, participants were required to select one of seven emotional labels (anger, sadness, happiness, fear, surprise, disgust, and neutral) they thought best described the face. Surcinelli et al. reported that recognition accuracy was equivalent across all emotional expressions with the exception of fear. Fearful faces were more accurately recognized by high-trait anxious compared with low-trait anxious participants. There are, however, two potential limitations to Surcinelli et al.'s (2006) study that question the specifics of their conclusion that trait anxiety is associated with an improvement in the ability to recognize fearful emotional expressions. Firstly, although Surcinelli et al. assume they are measuring recognition of the emotional facial expressions in their experiment, the details of their methodology are such that this assumption may not be appropriate. The faces in their experiment were presented for 10 s before a response was allowed. Recognition rates (i.e., the accuracy with which the emotional facial expressions are correctly identified) similar to those reported by Surcinelli et al. can be achieved with presentation times of only 100 ms (Prkachin, 2003). Thus, if the process of recognition takes only a fraction of the time allowed to Surcinelli et al.'s participants, it may not be recognition per se that is being measured in their study. For example, deployment of visual attention to emotional facial expressions is thought to differ between high- and low-anxious individuals with high-anxious individuals being less able to disengage their attention from threat-related faces (Fox, Russo, Bowles, & Dutton, 2001). Across the 10-s presentation time in Surcinelli et al.'s study, it could be that the high-anxious participants spend more time attending to the fearful faces than the low-anxious participants and this difference in attention could account for the reported difference in recognition. Furthermore, this relatively long presentation time of 10 s is a concern for reasons of ecological validity. In evolutionary terms, a 10-s latency for recognition of the emotional content of a conspecific's facial expression would render the system redundant in terms of signaling imminent danger. Thus, testing recognition rates following a shorter exposure duration would provide a more robust test of whether or not trait anxiety influences the recognition of emotional facial expressions and not some other cognitive process that might be influenced by anxiety in the 10 s that elapse before a response is made. Secondly, and presumably because of the 10-s exposure duration, only accuracy, and not reaction time, was recorded in Surcinelli et al.'s (2006) study. Accuracy, as a measurement, gives only an absolute value for whether or not the emotions on the faces were recognized correctly. It does not, for example, provide any information as to whether elevated levels of anxiety are associated with faster, more efficient, recognition of emotional expressions such as fear. There are many studies of information processing in anxiety that show differences in choice reaction time as a function of anxiety level, but no such differences in task accuracy (for a summary see Eysenck, Derakshan, Santos, & Calvo, 2007). Thus, reaction time to recognize the displayed emotion might be a more sensitive measure to assess the influence of anxiety on the processing of emotional facial expressions compared with accuracy alone. The Surcinelli et al. (2006) study is, to our knowledge, the only one to date that has examined recognition of emotional facial expressions as a function of non-clinical trait anxiety.3 However, similar studies using word and picture stimuli have provided equivocal findings. Across three experiments, and against their predictions, Mathews and Milroy (1994) found no evidence that anxious participants were any better at making a speeded valence judgment concerning negative words (e.g., funeral, stupid) than positive words (e.g., healthy, clever) when compared with non-anxious participants. In contrast, Bradley and Lang (1999) required participants to perform a very similar task to Mathews and Milroy, this time in response to the display of pleasant (e.g., flowers) and unpleasant (e.g., a snarling dog) images. They found anxious participants were faster at identifying the unpleasant images compared with non-anxious participants but there was no difference in participants’ ability to identify the pleasant images. Given the equivocal nature of findings in this area with non-face stimuli, we look again at the relationship between anxiety and the recognition of emotional facial expressions. The current study attempts to extend the work conducted by Surcinelli et al. (2006). A non-clinical sample of high- and low-trait anxious participants were asked to perform a speeded emotional facial expression recognition task in which both response time and accuracy were recorded. Following findings of Surcinelli et al. it was predicted that participants with high self-reported levels of trait anxiety should be more accurate in the recognition of fear compared to those with low levels of trait anxiety. In addition, following the work of Bradley and Lang (1999), response times to identify fearful emotional expressions should be faster in individuals with elevated levels of trait anxiety compared with individuals with low levels of trait anxiety.