دامنه خاص و حساسیت انزجاری عمومی در هراس از "جراحت - تزریق - خون": استفاده از روش/وظایف اجتناب رفتاری

The separate and combined roles of fear and disgust in mediating phobic responding in blood-injection-injury (BII) phobia have generated considerable empirical interest. The present study aimed to replicate previous research regarding fear and disgust responding to phobia-relevant and generalized disgust elicitors, as well as to provide a novel examination of performance on behavioral approach/avoidance tasks (BATs) and the “contaminated cookie” procedure (i.e., willingness to eat a cookie after it has come into brief contact with a threat-relevant stimulus). Fear and disgust responses toward pictures (mutilation, insects) and in vivo stimuli (bloody gauze, severed deer leg, cockroach, worm) were assessed in a sample of analogue BII phobics and nonphobics. Consistent with previous research, BII phobics expressed significantly greater fear and disgust toward phobia-relevant pictures and BAT stimuli, with disgust being the dominant emotional response. We failed to find any between-group differences on disgust responding toward the generalized disgust pictures and BAT stimuli. Results from the BATs suggest that BII phobics were less willing to perform all tasks involving blood stimuli, and less willing to complete the latter stages of the insect BATs. BII phobics were less likely to eat the “contaminated cookie” after it had come into contact with only the insect stimuli. Future implications for research examining domain-specific and generalized disgust sensitivity in BII phobia are outlined.

The separate and combined roles of fear and disgust in blood-injection-injury (BII) phobia have generated considerable interest in the empirical literature (Sawchuk, Lohr, Tolin, Lee, & Kleinknecht, 2000). While both emotions are characterized by avoidance of threat-relevant stimuli (Woody & Teachman, 2000), fear typically involves arousal of the sympathetic nervous system (Ekman, Levenson, & Friesen, 1983), whereas disgust evokes parasympathetic arousal (Levenson, 1992 and Rozin & Fallon, 1987; Rozin, Haidt, & McCauley, 1993). The potential to experience aversion, nausea, dizziness, and vasovagal syncope upon exposure to blood-injury stimuli has lead various authors to speculate that disgust serves a distinct role in BII phobia (Page, 1994 and Rachman, 1990; Tolin, Sawchuk, & Lee, 1999). Several studies have demonstrated that self-reported disgust among BII phobics is domain specific, characterized by heightened aversion toward mutilation, wounds, injections, and venipunctures. de Jong and Merckelbach (1998) found that measures of blood-injury fear correlated with animal-reminder disgust domains (e.g., envelope violations, death) assessed by the Disgust Scale (DS; Haidt, McCauley, & Rozin, 1994). This domain-specific disgust reactivity toward blood-injury stimuli has been largely replicated in analogue samples of BII phobics using both the Disgust Emotions Scale (DES; Walls & Kleinknect, 1996) and DS, when compared to spider phobics (Sawchuk et al., 2000; Sawchuk et al., in press and Tolin et al., 1997) and nonphobic (NP) controls (Sawchuk, Lohr, Lee, & Tolin, 1999). A number of studies have also suggested that BII phobics may be characterized by a generalized sensitivity to other classes of disgust elicitors completely unrelated to phobic concerns (e.g., rotting foods, smells, body products). The majority of these studies have found that analogue BII phobics do report significantly greater aversion toward these generalized domains on the DES and DS relative to NPs, although typically no significant between-group differences emerge, when directly comparing BII phobics to spider phobics (Sawchuk et al., 2000 and Sawchuk et al., in press; Tolin et al., 1997). The lack of between-phobia-group differences on generalized disgust domains suggests that generalized disgust sensitivity may serve a role in the onset and maintenance of disgust-related avoidance in small animal and BII phobias. A number of authors have forwarded alternative views regarding the phobia-disgust relationship. Thorpe and Salkovskis (1998) argue that disgust may not be directly involved in the etiology of spider phobia, and rather observed disgust reactivity is merely an amplified component of the primary phobic fear response. Alternatively, Woody and Teachman (2000) suggest that fear and disgust operate in a bi-directional, synergistic manner, with each emotion serving to intensify the experience of the other. Finally, Sawchuk et al. (in press) argue that while both fear and disgust co-occur in phobic responding, the dominant emotional label applied to the phobic stimuli likely involves consideration of the primary conditioned emotional response, the contextual features present during exposure, and idiosyncratic threat beliefs held by the individual. The findings generated from questionnaire research have also been replicated in studies in which BII phobics have been directly exposed to pictures and videos depicting BII stimuli and various disgust elicitors. Earlier research examining physiological reactivity among BII phobics to surgical videos suggested a response pattern of bradycardia and parasympathetic activity (Öst, 1992; Öst, Sterner, & Lindahl, 1984), which is related to the emotion of disgust (Levenson, 1992). Facial expressions of BII phobics upon exposure to surgical films have been found to be more associated with disgust than fear (Lumley & Melamed, 1992). Using a controlled attention task, Tolin et al. (1997) found that analogue BII phobics spent significantly less time viewing injection pictures, when compared to spider phobics and NPs, and other picture categories (i.e., spiders, appliances). Furthermore, affective ratings of the pictures indicated that BII phobics rated these pictures as significantly more fearful and disgusting than the other groups, with disgust being rated as the dominant emotion. These findings were replicated in a subsequent study in which analogue BII phobics were exposed to various surgical pictures (Sawchuk et al., in press). A limited number of studies have investigated BII phobics’ affective reactions during exposure to generalized disgust elicitors. Sawchuk et al. (1999) exposed analogue BII phobics and NPs to a disgust video depicting maggots and larvae. BII phobics not only reported significantly higher disgust than their NP counterparts, but also significantly higher fear and anger, which is suggestive of a pattern of negative affectivity. A subsequent study exposed BII phobics, spider phobics, and NPs to a video depicting solid waste management (Sawchuk et al., in press). Both phobic groups rated these scenes significantly more disgusting than the NP group. Furthermore, the same study found that BII phobics and spider phobics judged pictures of rotting foods and body products to be significantly more disgusting than the NP controls. In sum, the results of questionnaire research have been replicated during exposure to pictures and videos of generalized disgust elicitors. Despite growing evidence to support domain-specific and generalized disgust sensitivity reactions among BII phobics, the current study is the first to utilize a behavioral approach/avoidance task (BAT) to disgust stimuli in vivo. BATs provide a useful measure of phobic avoidance (Bellack & Hersen, 1988) and have been specifically applied in studies assessing disgust sensitivity in spider phobia. For example, approximately 75% of spider phobics refused to eat a preferred cookie in comparison to 30% of NP controls after a spider had come into brief contact with the food item (Mulkens, de Jong, & Merckelbach, 1996). Examining disgust-mediated avoidance using this methodology has become known as the “contaminated cookie” paradigm in which a previously preferred food item is rendered inedible following brief contact with a phobic object due to perceived transmission of contaminated properties. Phobic avoidance and rejection could, therefore, be construed as the unwanted physical contact with a repulsive phobic stimulus (de Jong, Vorage, & van den Hout, 2000). Given that the functional value of disgust is specifically related to the oral rejection of a potentially contaminated substance (Izard, 1993), the “contaminated cookie” paradigm has practical applications to the examination of disgust reactivity in BII phobia. Several BATs based on disgust domains measured by the DS have recently been developed (Rozin, Haidt, McCauley, Dunlop, & Ashmore, 1999) which offer a paradigm to examine disgust-mediated avoidance in phobic participants (Sawchuk et al., in press). The current study attempted to further explore the emotional responses of analogue BII phobics and NPs to pictures depicting blood-injury and general disgust elicitors (i.e., insects). We also directly examined disgust-mediated avoidance to domain-specific and generalized disgust elicitors by having participants engage in a series of BATs based on the “contaminated cookie” paradigm. Our specific hypotheses included the following: (1) analogue BII phobics would rate blood- and animal-related subscales on the DES significantly more disgusting than NPs; (2) BII phobics would rate fear and disgust significantly higher than NPs, when exposed to pictures depicting mutilation and insects; (3) BII phobics, relative to NPs, would endorse significantly more self-reported physical symptoms upon exposure to mutilation and insect stimuli; (4) BII phobics would be less willing to perform and complete the BATs involving actual exposure to various blood and insect stimuli; and (5) BII phobics would be less likely to consume a preferred cookie after it had come into brief contact with the blood and insect BAT stimuli.

Descriptive statistics of the BIIP and NP groups on the questionnaires are presented in Table 1. A 2 (DES subscale) mixed-factor ANOVA was conducted, using the DES subscales as the repeated measure. This analysis revealed significant main effects for subscale [F(2,142)=32.72, P<.0001] and group [F(1,71)=55.04, P<.0001], as well as a significant group×subscale interaction [F(2,142)=11.98, P<.0001]. One-way ANOVAs were conducted to examine the interaction. As predicted, the BIIP group rated DES subscales directly related to blood-injury stimuli (Mutilation and Death, Injections and Blood Draws) as significantly more disgusting than the NP group (). BII phobics also rated the Animals subscale as significantly more disgusting than the NP controls (P<.04).