Differential aversive outcome expectancies for high- and low-predation fear-relevant animals

Cognitive mechanisms of disgust in the development and maintenance of psychopathology: A qualitative review and synthesis

A growing body of research has implicated disgust in various psychopathologies, especially anxiety-related disorders. Although the observed role of disgust in many disorders is robust, the mechanisms that may explain this role are unclear. Cutting-edge research in cognitive science has the potential to elucidate such mechanisms and consequently improve our understanding of how disgust contributes to the etiology and maintenance of psychopathology. In this qualitative review, we systematically assess cognitive bias mechanisms that have been linked to disgust and its disorders. This review suggests that disgust-related biases may be observed in memory, interpretation, judgment of expectancies, and attention, as well as at implicit levels. Of these cognitive domains, the most robust bias appears to be observed at the level of attention. However, reliable moderators of attentional biases for disgust have not yet been identified, and this bias has not been systematically linked to other levels of analysis. Despite these limitations, the available research indicates that attentional avoidance rather than orienting or maintenance may be the most characteristic of disgust. Attentional avoidance of disgust may have important implications for etiological and treatment models of disorders characterized by excessive disgust reactions. The implications for advancing such models are discussed in the context of a combined cognitive bias hypothesis.

Effects of attitudes and demography on public support for endangered species conservation

It is critical for managers to understand how attitudes and demography affect public's preferences for species protection for designing successful conservation projects. 1080 adults in Greece were asked to rate pictures of 12 endangered species on aesthetic and negativistic attitudes, and intention to support their conservation. Factor analysis identified a group of animals for which respondents indicated high levels of support for their conservation (red deer, loggerhead sea turtle, brown bear, common pheasant, European ground squirrel, glossy ibis) and a group of animals for which respondents indicated low levels of support (black vulture, great white shark, fire-bellied toad, western barbastelle, Cretan tube web spider, Milos viper). The species that received the highest support were also rated as the most attractive and safest, excluding the fearsome brown bear. Structural models revealed that aesthetic, moralistic and negativistic attitudes were the stronger predictors of support. Aesthetic and moralistic attitudes were positively, and negativistic attitudes negatively, correlated with support for conservation in both groups. Consumptive users scored lower in aesthetics and were less supportive of protection in the high support group, while nonconsumptive users showed the opposite trend. Respondents residing in urban areas deemed animals of high support more attractive and less fearsome and were more supportive of conservation than rural residents in both groups. Females of higher education viewed animals of low support as fearsome, however they supported their conservation. Our study identified popular species that can be used as flagship species to facilitate the implementation of conservation projects. The results of this study could also be used to design a communication and outreach campaign to raise awareness about the ecosystem value of less attractive species.

Fear-relevant illusory correlations in different fears and anxiety disorders: A review of the literature

Fearful individuals often overestimate the relationship between fear-relevant stimuli and aversive consequences. Such fear-relevant illusory correlations (ICs) might be involved in the maintenance of anxiety disorders. In this literature review, we found clear evidence that ICs are present and enhanced in fear of animals. We also revealed some evidence for ICs related to fear of flying, social anxiety, contamination fear, panic disorder, and post-traumatic stress disorder, but with considerably less clarity. Fear-relevant ICs seem to be best explained by both a priori expectancies and biased encoding of the experienced associations. Studies to date suggest that one important biased encoding process is the enhanced aversiveness/salience of fear-relevant outcomes. Future studies may improve insight by developing more reliable IC measures and testing the effect of encoding processes on treatment outcomes.

Attention bias modification in specific fears: Spiders versus snakes

BACKGROUND AND OBJECTIVES

Attention Bias Modification (ABM) is used to manipulate attention biases in anxiety disorders. It has been successful in reducing attention biases and anxious symptoms in social anxiety and generalized anxiety, but not yet in specific fears and phobias.

METHODS

We designed a new version of the dot-probe training task, aiming to train fearful participants' attention away from or towards pictures of threatening stimuli. Moreover, we studied whether the training also affected participants' avoidance behavior and their physical arousal upon being confronted with a real threat object.

RESULTS

In Experiment 1, students with fear of spiders were trained. We found that the attention manipulation was successful, but the training failed to affect behavior or arousal. In Experiment 2, the same procedure was used on snake-fearful students. Again, attention was trained in the expected directions. Moreover, participants whose attention had been trained away from snakes showed lower physiological arousal upon being confronted with a real snake.

LIMITATIONS

The study involved healthy students with normal distribution of the fear of spider/snake. Future research with clinical sample could help with determining the generalizability of the current findings.

CONCLUSIONS

The effect of ABM on specific phobia is still in question. The finding in the present study suggested the possibility to alter attentional bias with a dot-probe task with general positive stimuli and this training could even affect the behavior while encountering a real threat.

Snakes and snakebite envenoming in Northern Tanzania: a neglected tropical health problem

Background

Snakebites cause considerable human and livestock injuries as well as deaths worldwide, and particularly have a high impact in sub-Saharan Africa. Generating a basic platform of information on the characteristics of snakes and snakebites in various countries is relevant for designing and implementing public health interventions.

Methods

This study was performed to identify types of snakes and some of the characteristics of snakebite cases in two communities, an agricultural and a pastoralist, in Arusha region, northern Tanzania. A total of 30 field visits were carried out in areas considered by local inhabitants to be potential microhabitats for snakes. Direct observation of snake types based on morphological features and a structured questionnaire were employed for data collection.

Results

A total of 25 live and 14 dead snakes were encountered. Among the dead ones, the following species were identified: two black-necked spitting cobras (Naja nigricollis); five puff adders (Bitis arietans), one common egg-eater (Dasypeltis scabra); two rufous-beaked snakes (Ramphiophis rostratus); two brown house snakes (Lamprophis fuliginosus); one Kenyan sand boa (Eryx colubrinus), and one black mamba (Dendroaspis polylepis). The frequency of snake encounters was significantly higher (χ² = 4.6; p = 0.03) in the pastoral than in the agricultural area; there were more snakebite cases in the former, but the differences were not statistically significant (p = 0.7). A total of 242 snakebite victims attended at the Meserani Clinic, located in the study area, between the years 2007 to 2012. Of all cases, 146 (61.6 %) and 96 (38.4 %) were male and female patients, respectively. As for age distribution, 59.1 % of snakebite victims were from the economically active age groups between 15 and 55 years.

Conclusion

Snakebites are a threat to rural communities and public health in general. The burden of snakebites in Tanzania presents an epidemiologically similar picture to other tropical countries. Livestock keeping and agriculture are the major economic activities associated with snakebites. Community-based public education is required to create awareness on venomous snakes and predisposing factors to snakebites. These tasks demand integration of diverse stakeholders to achieve a common goal of reducing the impact of human suffering from these envenomings in Tanzania.

In the grip of fear: dissociations in attentional processing of animal fearful individuals

Using a modified attention paradigm we investigated specific attentional mechanisms in processing animal feared stimuli. In this paradigm arrays of four pictures were displayed and after its disappearance from view a probe (a letter, X or P) then followed unpredictably in the location of one of the four pictures. The results showed that discriminations of probes tended to be impeded by spider stimuli, compared to snake stimuli. This effect was potentiated by high anxiety but only for those individuals fearful of spiders, since no such effect was observed for snake fearful individuals. Moreover, the discrimination of the probes was not facilitated when presented after the feared stimuli. The implications of these findings are discussed as a function of the cognitive bias involved in specific fear.

Rating data are underrated: validity of US expectancy in human fear conditioning

BACKGROUND AND OBJECTIVES

Human fear conditioning is widely regarded as one of the prime paradigms for the study of fear and anxiety disorders. We provide an evaluation of a commonly used subjective measure in the human fear conditioning paradigm, namely the US-expectancy measurement.

METHODS

We assess the validity of US-expectancy with respect to conditions of pathological fear and anxiety using four established criteria for scrutiny of a laboratory test or model (i.e., face validity, diagnostic validity, predictive validity, construct validity).

RESULTS

Arguably, there is sufficient evidence for the face validity, diagnostic validity, predictive validity and construct validity of the US-expectancy measure.

LIMITATIONS

Presumed limitations of the US-expectancy measure, including its susceptibility to experimental demand and memory bias, are discussed.

CONCLUSIONS

The US-expectancy measure is a valuable measurement method that can be effectively used in research that aims to enhance our understanding of fear and anxiety disorders.

A glimpse of fear: Fast detection of threatening targets in visual search with brief stimulus durations

Reliable detection of a threat based on temporally restricted information allows organisms to activate their defensive mechanisms. In the present study we investigated attentional efficiency for prototypical evolutionarily relevant stimuli, snakes (compared with spiders and mushrooms), during visual search conditions in which displays were presented for brief durations and under conditions of high perceptual load. Participants were exposed to a visual search paradigm in which the duration of the display varied between 150 and 300 ms. Perceptual load was manipulated using small, medium, and larger displays (4, 6, and 8 items, respectively). The results showed that fear stimuli, compared with neutral stimuli, were more accurately and quickly detected under both visually degraded conditions. The results also showed differences between the two categories of fear-relevant stimuli (snakes and spiders) in their dependency on perceptual load manipulations. Snake targets were overall detected more accurately than spiders, with this snake advantage effect being more clear-cut with many distracters (high load) than with few (low load). The results were interpreted in light of an evolutionary-based theory (the snake detection theory), which posits that snakes are the prototypical predators of primates.

Fear- and disgust-related covariation bias and eating disorders symptoms in healthy young women

Covariation bias refers to the phenomenon of overestimating the contingency between certain stimuli and negative outcomes, which is considered as a heuristic playing a role in the maintenance of certain types of psychopathology. In the present study, an attempt was made to investigate covariation bias within the context of eating pathology. In a sample of 61 female undergraduates, a priori and a posteriori contingencies were measured between pictures of obese and slim bodies, on the one hand, and fear- or disgust-relevant outcomes, on the other hand. Results indicated that participants in general displayed an a priori and an a posteriori covariation bias reflecting an overestimation of the link between obese bodies and disgust-relevant outcomes. However, this bias was not related to eating disorder symptomatology. Meanwhile, eating pathology was positively associated with a priori covariation biases referring to the associations between obese bodies and fear-relevant outcomes, and between slim bodies and disgust-relevant outcomes. All in all, these findings suggest that covariation bias plays a role in eating pathology.

Disgust and fear-related UCS-expectancy bias in blood-fearful individuals

People with specific fears tend to overestimate the occurrence of unpleasant consequences in situations involving their feared objects. Such expectancy bias logically acts in a way to confirm phobic fear and avoidance. Increasing evidence suggests that blood phobia is qualitatively different from other specific phobias. Confrontation with phobic stimuli gives rise to disgust and repulsion rather than (threat-induced) fear. Therefore, this study examined the role of disgust-related UCS expectancies following confrontation with blood phobia-relevant stimuli. Using a thought-experiment procedure, high (n = 30) and low (n = 30) blood-fearful individuals estimated the probability that the presentation of slides showing a bloody wound and a series of filler slides would be followed by a sip of nauseating juice, a threat-related electrical shock or nothing. Although participants generally expected shock and juice following blood, UCS expectancies for both aversive outcomes for blood were significantly more pronounced in high blood-fearful participants. This implicates that UCS-expectancy biases may be involved in the development and maintenance of blood phobia.

Asymmetrical stimulus generalization following differential fear conditioning

Rodent ultrasonic vocalizations (USVs) are ethologically critical social signals. Rats emit 22kHz USVs and 50kHz USVs, respectively, in conjunction with negative and positive affective states. Little is known about what controls emotional reactivity to these social signals. Using male Sprague-Dawley rats, we examined unconditional and conditional freezing behavior in response to the following auditory stimuli: three 22kHz USVs, a discontinuous tone whose frequency and on-off pattern matched one of the USVs, a continuous tone with the same or lower frequencies, a 4kHz discontinuous tone with an on-off pattern matched to one of the USVs, and a 50kHz USV. There were no differences among these stimuli in terms of the unconditional elicitation of freezing behavior. Thus, the stimuli were equally neutral before conditioning. During differential fear conditioning, one of these stimuli (the CS(+)) always co-terminated with a footshock unconditional stimulus (US) and another stimulus (the CS(-)) was explicitly unpaired with the US. There were no significant differences among these cues in CS(+)-elicited freezing behavior. Thus, the stimuli were equally salient or effective as cues in supporting fear conditioning. When the CS(+) was a 22kHz USV or a similar stimulus, rats discriminated based on the principal frequency and/or the temporal pattern of the stimulus. However, when these same stimuli served as the CS(-), discrimination failed due to generalization from the CS(+). Thus, the stimuli differed markedly in the specificity of conditioning. This strikingly asymmetrical stimulus generalization is a novel bias in discrimination.

Blood-injection-injury fears: harm- vs. disgust-relevant selective outcome associations

There is increasing evidence that blood-injection-injury (BII) phobia is qualitatively different from the other specific phobias in the sense that phobic distress takes the form of disgust rather than (threat-induced) fear. Following this, we tested the relative importance of harm and disgust-related associative biases in BII-fear. High (n=25) and low (n=27) fearful individuals saw a series of fear-relevant (blood-related) and fear-irrelevant (rabbit and flower) slides which were randomly paired with either a harm-related outcome, a disgust-related outcome, or nothing. Preexperimentally, participants expected blood-related slides to be followed by both disgust- and harm-relevant outcomes. These selective preexperimental outcome expectancies were readily corrected during the experiment. Neither low nor high fearful participants showed a postexperimental covariation bias. The absence of differential effects between high and low fearful participants does not support the idea that disgust- or harm-relevant associative biases play a role in the maintenance of BII-fears. The results corroborate the previous finding of Pury and Mineka [1997. Covariation bias for blood-injury stimuli and aversive outcomes. Behaviour Research and Therapy, 35, 35-47] that people are generally liable to selectively associate BII-stimuli with aversive outcomes.

Contamination vs. harm-relevant outcome expectancies and covariation bias in spider phobia

There is increasing evidence that spiders are not feared because of harmful outcome expectancies but because of disgust and contamination-relevant outcome expectancies. This study investigated the relative strength of contamination- and harm-relevant UCS expectancies and covariation bias in spider phobia. High (n=25) and low (n=24) spider fearful individuals saw a series of slides comprising spiders, pitbulls, maggots, and rabbits. Slides were randomly paired with either a harm-relevant outcome (electrical shock), a contamination-related outcome (drinking of a distasting fluid), or nothing. Spider fearful individuals displayed a contamination-relevant UCS expectancy bias associated with spiders, whereas controls displayed a harm-relevant expectancy bias. There was no evidence for a (differential) postexperimental covariation bias; thus the biased expectancies were not robust against refutation. The present findings add to the evidence that contamination ideation is critically involved in spider phobia.

Differential UCS expectancy bias in spider fearful individuals: evidence toward an association between spiders and disgust-relevant outcomes

Recently, differential UCS expectancies were found for high- and low-predatory fear-relevant animals [Davey, G. C. L., Cavanagh, K., & Lamb, A. (2003). Differential aversive outcome expectancies for high- and low-predation fear-relevant animals. Journal of Behavior Therapy and Experimental Psychiatry, 34, 117-128]. The present study extends these findings to spider phobia. In a hypothetical experiment, high (n = 27) and low (n = 28) spider fearful individuals estimated the probability that slides of spiders, maggots, pit bull terriers, or rabbits would be followed by a sip of nauseating juice, a shock, or nothing. Maggots were selectively associated with the disgusting juice, pit bull terriers with the harm-related shock, and rabbits with nothing. Spiders were associated with both aversive UCSs, but significantly stronger in the high fear group. Additionally, an expectancy bias toward disgust-relevant consequences was the single best predictor of spider fear. These findings imply that in accordance with the disease-avoidance model, expectations of disgust-relevant consequences are involved in spider phobia.