هویت و بیان حافظه برای چهره شاد و عصبانی در اضطراب اجتماعی
|کد مقاله||سال انتشار||مقاله انگلیسی||ترجمه فارسی||تعداد کلمات|
|32731||2003||15 صفحه PDF||سفارش دهید||7359 کلمه|
Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Acta Psychologica, Volume 114, Issue 1, September 2003, Pages 1–15
We examined the influence of social anxiety on memory for both identity and emotional expressions of unfamiliar faces. Participants high and low in social anxiety were presented with happy and angry faces and were later asked to recognise the same faces displaying a neutral expression. They also had to remember what the initial expressions of the faces had been. Remember/know/guess judgements were asked both for identity and expression memory. For participants low in social anxiety, both identity and expression memory were more often associated with “remember” responses when the faces were previously seen with a happy rather than an angry expression. In contrast, the initial expression of the faces did not affect either identity or expression memory for participants high in social anxiety. We interpreted these findings by arguing that most people tend to preferentially elaborate positive rather than negative social stimuli that are important to the self and that this tendency may be reduced in high socially anxious individuals because of the negative meaning they tend to ascribe to positive social information.
Cognitive theories of social phobia are based on the idea that differences in how individuals process social/evaluative information may be causal in the development or maintenance of the disorder (Clark & Wells, 1995; Rapee & Heimberg, 1997). Accordingly, researchers have investigated whether social phobics and non-clinical individuals high in social anxiety show biases towards processing socially threatening information at several levels within the information-processing system. The literature clearly indicates that social phobia is associated with an attentional bias towards socially threatening words and an interpretational bias towards self-relevant social information (see Eysenck, 1999; Heinrichs & Hofmann, 2001; Musa & Lépine, 2000 for reviews). On the other hand, the existence of a memory bias has received mixed support in research. Several studies have failed to find an explicit memory bias both in social phobics (Cloitre, Cancienne, Heimberg, Holt, & Liebowitz, 1995; Lundh & Öst, 1997; Rapee, McCallum, Melville, Ravenscroft, & Rodney, 1994) and in non-clinical individuals high in social anxiety (Foa, McNally, & Murdock, 1989; Sanz, 1996). In contrast, other studies have found that non-clinical individuals high in social anxiety tend to recall more negative words than individuals low in social anxiety (Breck & Smith, 1983; O’Banion & Arkowitz, 1977). Finally, Mansell and Clark (1999) found that non-clinical individuals high in social anxiety tended to recall less positive adjectives than individuals low in social anxiety but only when information was encoded in reference to their public self and when they were anticipating a social evaluation. However, high and low socially anxious participants were not significantly different with regard to recall of negative adjectives. When considering these divergent results, a recent review of information processing in social phobia concludes that ‘… the literature reports little evidence to suggest that social phobia is associated with a memory bias’ (Heinrichs & Hofmann, 2001, p. 763). The majority of studies have used verbal stimuli in order to investigate memory bias in social anxiety and this may be problematic for several reasons. First, it has been argued that words are only indirect representations of threat and that studies should try to use more ecologically valid stimuli like facial expressions connoting approval or disapproval because these stimuli are directly related to social evaluations (Mogg & Bradley, 1999). Second, Clark and Wells (1995) argued that word-processing studies are modelling attention to mental preoccupations rather than attention to actual social cues, whereas the reverse is true for studies that used more ecological stimuli like faces. Taking these reflections into account, it might be more appropriate to use faces as stimuli if one wants to investigate potential memory biases in social anxiety. The human face is a highly significant social stimulus which provides various information that can be used to recognise familiar people and also to infer people’s age, gender, or emotional state (Bruce & Young, 1986). Among all these information, information about face identity and emotional expressions are probably the most salient and important aspects of non-verbal communication in social situations. Accordingly, memory for these two kinds of information might be especially interesting to study in social anxiety. As far as we know, only one published study examined memory for the identity of new faces in social anxiety. Lundh and Öst (1996) presented photos of faces to social phobics and control participants, asking them to state whether the persons on the photos looked critical or accepting. Participants were then faced with an unexpected recognition task in which they were presented with photos of individuals encountered in the encoding task along with distracter photos depicting other individuals and they were asked to identify the faces they had seen previously. There was no difference between social phobics and controls in terms of overall memory for the faces. However, social phobics recognised more faces they had rated as critical than faces they had rated as accepting, whereas controls tended to display the opposite pattern. One could conclude from these findings that identity memory for critical faces is enhanced in social phobia. However, as the authors acknowledged, the design of the study does not permit to determine whether the results are due to a true memory bias or to a response bias. It is indeed possible that social phobics tended to designate critical faces as familiar regardless of whether they had seen them before. To explore this alternative explanation, a comparison of the hits and false alarms for each face category (critical vs. accepting) should have been conducted. However, this was not possible because participants did not rate the degree of critical attitude of the distracter faces shown during the recognition task. It is therefore impossible to draw clear conclusions about identity memory from Lundh and Öst’s results. Memory for facial expressions themselves may also be worthy of interest in social anxiety. Indeed, memory for expressions connoting approval or disapproval probably plays an important role in the retrospective evaluation of social situations and consequently it could influence the way one interprets and apprehends current and future interactions. Expression memory was recently examined by Foa, Gilboa-Schechtman, Amir, and Freshman (2000) and Pérez-Lopez and Woody (2001). In the first experiment reported by Foa et al. (2000), patients with social phobia and control participants learned the names of several faces. They were then presented with photos of the same individuals displaying happy, angry, or neutral expressions and they were asked to name the person on the photo again and also to label his or her emotional expression as happy, angry, or neutral. Finally, they completed a free recall test in which they were asked to write down the names and the expressions of the individuals they had seen previously and a cued recall test in which they were provided with the names of the individuals and were asked to write down the corresponding expressions. Patients with social phobia had an overall better memory for facial expressions than control participants in both tests. Moreover, a memory bias towards threatening (angry) faces in social phobia was found, but only in the cued recall test. In the second experiment reported by Foa et al. (2000), participants were presented with photos of individuals displaying neutral, happy, angry, and disgusted expressions. They were then presented with the same photos interspersed with photos of the same individuals displaying different emotional expressions and they were asked to recognise the photos they had seen previously. Recognition of facial expressions was overall better in patients with social phobia than in control participants. Moreover, patients with social phobia recognised negative facial expressions (anger, disgust) better than other expressions whereas this was not the case for control participants. Finally, in the study reported by Pérez-Lopez and Woody (2001), patients with social phobia and control participants were presented with faces displaying either a threatening or a reassuring expression while they were waiting to give a speech in front of an audience. They subsequently completed a forced-choice recognition test in which they viewed pairs of photos consisting of one of the photos seen during the encoding phase and another picture of the same individual displaying a facial expression opposite in valence to the first one. Results showed that patients with social phobia had an overall poorer recognition for facial expressions. However, the difference between the two groups was no longer significant when state anxiety was controlled. In addition, patients with social phobia showed a small bias toward remembering reassuring facial expressions over threatening facial expressions. The findings concerning memory for emotional expressions reported by Foa et al., on the one hand, and by Pérez-Lopez and Woody, on the other, are inconsistent. However, these studies suffer from several limitations. Firstly, one cannot conclude from Foa et al.’s first experiment that social phobics had a better memory for emotional expressions themselves. Indeed, participants were asked to name each face depicted on the photos and to label the corresponding expression. In these conditions, it is possible that participants recalled the associations between the names and the verbal labels for the expressions rather than the visual aspect of the expressions themselves. Secondly, in the second experiment reported by Foa et al., the individuals depicted on the photos were not presented with all expressions (each model was represented with a neutral and one emotional expression, either happy, angry, or disgust). This made it impossible to look for the effect of particular emotional expressions unconfounded with differences in the memorability of particular people’s faces. Finally, and more importantly, in Foa et al.’s second experiment as well as in Pérez-Lopez and Woody’s study, the same photos were used during the encoding and recognition phases. This poses a problem of interpretation because, as Bruce (1982) has pointed out, the recognition of identical photos and the recognition of faces (or, as this is the case here, the recognition of facial expressions) are distinctly different tasks. Indeed, recognition of photos may depend as much on remembering pictorial details (e.g., details of the lighting, grain and flaws in the photos) as it does on remembering the faces and the facial expressions depicted. Thus, it is not possible to know if individuals actually remembered the expressions of the faces in those studies. Furthermore, the use of a recognition task may not be the best way to assess expression memory. Indeed, in everyday life, we rarely try to remember what the expression of an individual was in a previous situation by seeing the same expression again and choosing it among distracters. Instead, we more probably try to retrieve and reconstruct a visual representation of what that expression was. Accordingly, recall or cued recall tasks might be more appropriate and more ecological to assess expression memory. When considering the reflections we developed above, it is difficult to draw clear-cut conclusions from the existing studies either about identity or expression memory in social anxiety. Accordingly, the present study was designed to address the methodological problems of previous studies in order to further investigate the potential influence of social anxiety on both identity and expression memory. Participants high and low in social anxiety were presented with happy and angry faces and were later asked to recognise neutral faces of the same individuals. This change of the expression of the faces between presentation and test enabled us, on the one hand, to be sure that memory performances would reflect face recognition rather than mere stimulus recognition, and, on the other hand, to investigate memory bias without confounding with response bias. When a face was claimed to be recognised, expression memory was also assessed by asking participants to decide whether this face had been presented earlier with a happy or an angry expression. A second purpose of the present study was to examine qualitative aspects of identity and expression memory (see Gardiner & Richardson-Klavehn, 2000; Wheeler, Stuss, & Tulving, 1997). Indeed, face recognition can be associated with different states of awareness. In many cases, recognition of a face is accompanied by a recollection of something that occurred or something that one experienced (what one thought or felt) when this face was seen previously. In other cases, a face can be recognised because it evokes strong feelings of familiarity but nothing about its prior occurrence can be remembered. An investigation of these qualitative aspects of memory with the remember/know/guess procedure (see Gardiner & Richardson-Klavehn, 2000) enabled us to investigate both identity and expression memory in a more precise way. Indeed, recent findings suggest that the effect of emotion on memory, and especially the comparison of memory for positive and negative stimuli, is not always reflected in overall recognition scores but may nevertheless be located in qualitative aspects of recognition memory (Dewhurst & Parry, 2000; Ochsner, 2000). Similarly, it might be that the influence of social anxiety on memory for positive and negative social stimuli is more easily detected when one takes qualitative aspects of memory into account. In particular, if, as argued by Clark and Wells (1995), social anxiety is associated with a tendency to allocate fewer attentional resources to process social stimuli, one should observe a decrease in the frequency of rich recollections of the faces and their expressions (as assessed by “remember” responses) for people high compared to low in social anxiety. Indeed, extensive research has shown that “remember”, but not “know”, responses are affected by the amount of attention allocated to the stimuli and by the elaboration of their encoding (Gardiner, 1988; Gardiner & Parkin, 1990; see Gardiner & Richardson-Klavehn, 2000 for a review). In addition, if, as assumed by Rapee and Heimberg (1997), socially anxious people tend to preferentially process socially threatening rather than reassuring stimuli, participants high in social anxiety should specifically report more “remember” responses for angry than for happy faces. These predictions were examined in the present study.