تاثیر بروز ترس در پردازش خطر: نفوذ سطح اضطراب خصلتی

Threat estimation is crucial for the adaptation of behavior to a dangerous situation. In anxiety, a bias to threat has been described as a core feature. Therefore, the sensitivity for threatening information in anxious individuals may have consequences for danger estimation. In this study, we used the affective priming paradigm to test the assumption that fearful expressions would facilitate danger detection in natural scenes in anxious individuals. Twenty-three high trait anxious individuals and 22 low trait anxious individuals participated in the study. They had to detect the potential threat of a target scene (neutral or threatening) following neutral or fearful face primes. High trait anxious participants detected threat more rapidly than low trait anxious participants, consistent with previous reports of emotional hypervigilance in anxiety. Furthermore, this effect was enhanced when the target scene followed a fearful expression: Only in anxious participants were reaction times shorter to detect danger following a fearful prime than a neutral prime. Our results tend to show that in anxiety, the hypervigilance to threat may be of an important value such as increasing the detection of a subsequent potential danger. Implication of attentional processes and attentional control is discussed.

Cognitive models of anxiety assume that the etiology and maintenance of anxiety disorders are related to individual differences in the processing of threat-related material (Beck and Clark, 1997, Eysenck and Calvo, 1992 and Mathews and MacLeod, 2002). According to these models, anxiety would be dependent on distorted perceptions of danger. Research findings have provided strong support for the hypothesis that anxiety is associated with cognitive biases for threatening information. Anxious individuals selectively attend to potentially threatening stimuli. Such attentional biases for threat have been widely observed both in clinical anxiety and in non clinical high trait anxiety and replicated using a variety of paradigms (Bar-Haim, Lamy, Pergamin, Bakermans-Kranenburg, & van IJzendoorn, 2007). Those biases may appear at different stages of information processing: In the early stages, an automatic attentional orienting to threat has been shown in paradigms such as the dot probe, the visual search and the spatial cueing paradigms (Carlson and Reinke, 2008, Juth et al., 2005, Koster et al., 2006 and Rinck et al., 2003). For example, dot probe tasks showed that high trait anxious individuals (HTA) are quicker at responding to probes in the location of a threat stimulus than a neutral stimulus (Mogg & Bradley, 1999). This tendency for threatening stimuli to attract attention to a greater extent in anxious individuals also results in a later difficulty in disengaging attention from such stimuli (Amir et al., 2003, Lipp and Waters, 2007, Salemink et al., 2007 and Van Damme et al., 2006). Globally, compared to controls, anxious individuals orient their attention to threatening stimuli more than to neutral stimuli (Cisler & Koster, 2010). Consistent with this attentional bias for threat, anxious individuals show enhanced processing of threat related information. Using the face in the crowd paradigm (Hansen & Hansen, 1988), some data established that HTA individuals were faster than low-trait anxious (LTA) individuals to detect angry faces in a neutral crowd (Byrne & Eysenck, 1995). Anxious individuals not only detect threat more quickly than do LTA individuals, they also recognize fear more accurately (Surcinelli, Codispoti, Montebarocci, Rossi, & Baldaro, 2006). Besides, fearful faces may influence attentional processes in high anxious individuals (Georgiou et al., 2005 and Ladouceur et al., 2009) and previous studies showed a bias towards facilitated processing of fearful faces in anxiety (Avram, Balteş, Miclea, & Miu, 2010). Although fearful faces are not threatening in their appearance, they may be interpreted as such by anxious individuals since fear expression is considered to indicate danger in the environment. Emotional facial expressions act as functions of signalization; they are recognized as an important fundamental social phenomenon (Kaiser, Wehrle, & Schenkel, 2009). According to LeDoux (1996), fearful expressions may facilitate danger detection. For Frijda, 1953 and Frijda, 1986, emotional facial expressions are similar to a way of action preparation. Frijda distinguishes three possible reactions of an observer in front of a facial expression, of which “environmental expectation”. This behavior is defined by the allocation of attention on a particular object or by arousing expectation of this object. The perception of fear expression, for example, may induce such a reaction by indicating the presence of a threat in the environment. Recently, Browning and Harmer (2012) found that threat expectation may influence deployment of attention to threat. Their results suggest that expectancy-based processes are involved in the control of attention to threatening information and that these processes are perturbed in anxiety. Indeed, they obtain a negative correlation between high levels of trait anxiety of the participants and the threat-expectation signal measured in attentional control and visual cortical structures. However, this relationship was not observed in their behavioral data. The present study is based on this idea that threat expectation influences the control of attention, and that perturbed expectancy based processes may lead to attentional biases in anxious individuals. As described above, fearful facial expressions represent a signal of potential danger and arouse threat expectation. We suggest therefore that perception of a fearful expression involves a lack of attentional control in anxious individuals, by increasing threat expectation. To test this assumption we used a behavioral task based on the affective priming paradigm. Specifically, we analyzed the effect of a neutral or fearful face prime on the detection of danger in complex scenes representing physically dangerous real situations, as a function of trait anxiety level. Traditionally, the affective priming paradigm implies that participants evaluate the emotion depicted by a target stimulus of either positive or negative valence preceded by an emotional prime stimulus (Fazio, Sanbonmatsu, Powell, & Kardes, 1986). Such studies using the affective priming paradigm have evidenced facilitation for the processing of emotional information. The affective priming effect thus relates to shorter reaction time recorded when the prime and target have the same valence than for incongruent prime-target pairs (Aguado et al., 2007, Calvo and Avero, 2008, Carroll and Young, 2005 and Storbeck and Clore, 2008). The spreading of activation in memory has been proposed to be the mechanism responsible for the affective priming effect: the presentation of the prime was presumed to temporarily enhance the activation level of the associated affective evaluation (Fazio, 2001). More precisely, a recent ERP study showed that two mechanisms participate to the affective priming effect in an evaluation task: semantic priming and response priming (i.e. automatic activation of the evaluative response through the affective prime) (Eder, Leuthold, Rothermund, & Schweinberger, 2012). Besides, other authors underline the importance of attention for the appearance of the affective priming effect (Calvo and Nummenmaa, 2007 and De Houwer and Randell, 2002). Using face material, Li, Zinbarg, Boehm, and Paller (2008) found that affective ratings of emotional faces were more influenced by the expression of a subliminal fearful face prime the higher the individual’s trait anxiety level. That is, surprised faces were more often rated as negative when preceded by a subliminal fearful prime with anxiety level increasing. This result goes along with the notion that the processing of fearful faces is facilitated or enhanced in anxiety. In the present study, we aim to test the hypothesis that a threat stimulus, such as a fearful expression, would modulate differently the subsequent detection of danger in anxious individuals compared to controls. Taking into account the arguments demonstrating an enhanced processing of threat in anxiety, we presume that, in the context of the affective priming paradigm, the detection of dangerous target scenes will be facilitated in anxious individuals compared to non anxious participants when preceded by a fearful face prime.

According to the evaluation model of Lazarus (1966), estimation of the danger conveyed by a stimulus is the first step towards developing strategies leading to the adaptation of behavior. In a real situation of threat, danger evaluation can be determinative for survival. The results of our study provide new insight into threat processing in anxiety. We brought evidence that in HTA individuals, the perception of a fearful face as a signal of potential danger may facilitate the subsequent detection of danger in a complex scene. In anxiety, the hypervigilance to threat may be of an important value such as increasing the detection of a subsequent potential danger. However, our study presents a main limitation, that the specificity of fearful expressions cannot be demonstrated. To specify the bias for fear, future research should include other negative stimuli, such as anger expressions for example.