Origins and development of human fear reactions

Rule-governed behavior: Unifying radical and paradigmatic behaviorism

Commonalities and differences between Skinner's analysis of verbal behavior and the paradigmatic behaviorism (PB) approach are described as a means of introducing the latter to behavior analysis. The focus is on treating the topic of rule-governed behavior-a topic of current interest in behavior analysis in addressing the challenge of cognitive psychology-within the PB framework. Dealing behaviorally with traditional psychology interests is considered important in PB, and this article aims to advance toward that goal. PB has presented a framework that deals with not only the behavioral description of language but also with language function as well as language acquisition. This includes a treatment of the manner in which verbal stimuli generally can control motor behavior. This framework includes analyses in addition to those present in the behavior analytic framework, along with empirical developments, and these can be used to enhance a behavioral understanding of important parts of verbal behavior and the effects of verbal stimuli on behavior, including rule-governed phenomena. Our purpose is to use the particular topic of rule-governed behavior to argue that a more explicit interaction between radical and paradigmatic behaviorism would advance behaviorism and also enable it to have a stronger impact upon psychology and the scientific community.

The vicarious learning pathway to fear 40 years on

Forty years on from the initial idea that fears could be learnt vicariously through observing other people's responses to a situation or stimulus, this review looks at the evidence for this theory as an explanatory model of clinical fear. First, we review early experimental evidence that fears can be learnt vicariously before turning to the evidence from both primate and human research that clinical fears can be acquired in this way. Finally, we review recent evidence from research on non-anxious children. Throughout the review we highlight problems and areas for future research. We conclude by exploring the likely underlying mechanisms in the vicarious learning of fear and the resulting clinical implications.

Evaluative learning and emotional responding to fearful and disgusting stimuli in spider phobia

The present study explores possible changes between spider phobics (N=22) and nonphobics (N=28) in fear, disgust, and neutral ratings of neutral expressions as a result of their pairing with spiders. No statistically significant differences were detected between pre and post fear ratings of the expressions as a result of their association with spiders. However, post disgust ratings were marginally higher than pre disgust ratings and post neutral ratings were significantly lower than pre neutral ratings. The present study also examined differences in fear and disgust responding to threat-relevant and disgust-relevant stimuli between spider phobics and nonphobics. Spider phobics reported significantly more fear and disgust than nonphobics towards threat and disgust-relevant stimuli. The relation between spider phobia and disgust responding to spiders was partially mediated by fear whereas the relation between spider phobia and disgust responding to rotting foods and body products was fully mediated by fear. Emotional responding to threat-relevant and disgust-relevant stimuli was also significantly associated with disgust sensitivity when controlling for trait anxiety. These findings support the notion that the disgust response in spider phobia is independent of fear to the extent that it is specifically bound to spiders.

Cognitive vulnerability: a model of the etiology of fear

This paper attempts to fill the partial theoretical vacuum surrounding the understanding of fear acquisition. A review of recent and contemporary theories of the etiology of fear is presented, serving as a justification for further theorizing and allowing for greater understanding of those aspects of fear that remain to be adequately explained. A new model of the etiology of specific fears is subsequently put forward and the various aspects and implications of this model are discussed. How an individual perceives a stimulus is proposed as being critical in determining fear in relation to the stimulus. In particular, perceptions of the stimulus as uncontrollable, unpredictable, dangerous and disgusting create a schema of vulnerability. The Cognitive Vulnerability Model integrates much of the extensive body of research on fears and specific phobias into a unifying theory of the etiology of fear. The model offers parsimonious explanations for the various characteristics of specific fears and phobias.

Using facial expressions as CSs and fearsome and disgusting pictures as UCSs: affective responding and evaluative learning of fear and disgust in blood-injection-injury phobia

Two experiments examine use of an evaluative conditioning (EC) paradigm in the acquisition of fear and disgust responding to neutral facial expressions. In Experiment 1, 60 participants were randomly assigned to one of three evaluative learning conditions in which neutral facial expressions were paired with fearsome, disgusting, or neutral pictures. No statistically significant differences were detected between the three conditions. However, significant differences emerged within subjects as post-exposure of fear and disgust ratings were higher among expressions that were paired with pictorial stimuli. Experiment 2 sought to examine if an analogue sample of BII phobics would be more susceptible than nonphobic controls to fear and disgust EC utilizing a similar experimental design, given the co-occurrence of fear and disgust in BII-phobic responding. Results failed to demonstrate an EC effect specific to the analogue phobic group, although both groups showed an evaluative shift toward disgust for those facial expressions paired with BII-relevant pictures. Consistent with previous findings, examination of picture rating data suggested that analogue BII phobics rated the BII pictures as significantly more disgusting than fearful. The role of EC processes and a priori expectancy biases in the associative learning of disgust in BII phobia is discussed.

Multimodal classical conditioning of fear: contributions of direct, observational, and verbal experiences to current fears

The authors propose that a multimodal classical conditioning model be considered when clinicians or clinical researchers study the etiology of fears and anxieties learned by human beings. They argue that fears can be built through the combined effects of direct, observed, and verbally presented classical conditioning trials. Multimodal classical conditioning is offered as an alternative to the three pathways to fear argument prominent in the human fear literature. In contrast to the three pathways position, the authors present theoretical arguments for why "learning by observation" and "learning through the receipt of verbal information" should be considered classical conditioning through observational and verbal modes. The paper includes a demonstration of how data, commonly collected in research on the three pathways to fear, would be studied differently using a multimodal classical conditioning perspective. Finally, the authors discuss implications for assessment, treatment, and prevention of learned fears in humans.

Using mental imagery with subclinical OCD to 'freeze' contamination in its place: evidence for looming vulnerability theory

The present research examines the possibility that 'freezing' or slowing-down the rate at which threats can advance and thereby blocking a sense of looming vulnerability can reduce fears of contamination and avoidance behavior among individuals with obsessional symptoms. Mental imagery was used to reduce the rate at which threat can advance by means of instructions to imagine that contamination was 'frozen' in place and unable to move. Measures included self-reports of anxiety and worry, and indirect assessments of fear and avoidance behavior. A parallel mental imagery condition was used to examine the possibility that accentuating the spread or contamination, or its 'looming', would in turn accentuate fear and avoidance. The results, particularly of the more unobtrusive measures, indicated that freeze imagery reduced fear and avoidance for the relatively obsessional participants. In addition, support was found that it reduced fear for participants with relatively higher levels of imagination. However, the freeze imagery paradoxically seemed to sensitize the non-obsessional participants to possibilities of contamination they had not previously considered, and thus increased their fear. The results provide support for the looming vulnerability model of anxiety and suggest applications to treatment.

Looming vulnerability to spreading contamination in subclinical OCD

The present study examined the hypothesis, stimulated by the looming vulnerability model of anxiety (Riskind, in press, Behaviour Research and Therapy), that subclinical OCD is associated with a subjective sense of looming vulnerability. One-hundred and four undergraduates rated vignettes of common, everyday situations involving exposure to possible dirt, germs, or contamination. Participants in a subclinical obsessional group had a far higher sense of looming vulnerability to spreading contamination than did those in a control group. Results verified that the subjective sense of looming vulnerability still had separate, distinct and significant contributions to fear-of-contamination symptoms, with the effects of cognitive appraisals of other aspects of threat (such as probability of harm, or lack of control) removed. In contrast, these other cognitive appraisals had no significant associations with symptoms that proved to be independent of the subjective sense of looming vulnerability. A path analysis further explored the dependency of these other cognitive appraisals on looming vulnerability. This analysis found that part of the effects of the subjective sense of looming vulnerability on fears may be indirect and mediated via correlated effects of other cognitive appraisals.

The looming of spiders: the fearful perceptual distortion of movement and menace

The current study examined the relation between the perception that fear-stimuli are looming and fearful cognitive distortions. As hypothesized, high-fear-of-spider Ss were significantly more likely than low-fear Ss to imagine that a spider in a room would move rapidly and selectively to them in proximity, rather than towards three other individuals in the same physical space. This finding was observed with a measure of perceptual-cognitive distortion as well as with self-reports. High-fear Ss were also more likely to perceive spiders as angry and belligerent, as intending to move towards them, and as singling them out from other people. These results suggest that perceptions of looming danger and fearful cognitive distortions are closely linked phenomena. Finally, the perception that spiders are looming and the other cognitive variables could be used to successfully classify the fear-group memberships of the Ss in 98% of the cases. Perceptions that spiders are looming made the single largest unique contribution to the discriminant classification function.

Effects of endorphin blocking on conditioned SCR in humans

In order to test the hypothesis that low levels of endogenous opioids (endorphins) predispose to strong conditioning effects, female Ss (N = 36) were assigned to a placebo group, a low-dose naltrexone group, or a high-dose naltrexone group and then underwent a classical conditioning procedure. This procedure consisted of an acquisition phase in which all Ss received 5 pairings of a CS+ (neutral picture) and a UCS (100 dB white noise). The CS- (neutral picture) was never followed by a UCS. During extinction, Ss received 4 unreinforced presentations of CS+ and CS-. Throughout the experiment, skin conductance responses (SCRs) to the CSs and UCSs were recorded. Acquisition was successful in that CS+ slides elicited stronger SCRs than CS- slides. However, during acquisition, there was no interaction between drug and differential response (CS+ vs CS-). During extinction, there was no overall remaining effect of conditioning. Again, no evidence was found to suggest that (remaining) effects of conditioning were stronger in the naltrexone treated Ss than in the placebo Ss. If anything, the opposite seemed to be true with especially high-dose naltrexone Ss showing relatively weak conditioning effects.

Pathways to spider phobia

Using a revised version of the Phobic Origin Questionnaire (POQ; Ost, L. G. & Hugdahl, K. Behaviour Research and Therapy, 19, 439-477; 1981), the present study examined whether conditioning experiences, modeling experiences, and/or informational learning experiences were more often reported by spider phobics (n = 41) than by non-fearful controls (n = 30). The two groups did not differ with regard to the overall frequency of conditioning or modeling events. Remarkably, the frequency of informational learning was higher among non-fearful Ss than among phobics. Although the limitations inherent to the retrospective nature of the present study should be borne in mind, the data suggest that, at least in spider phobics, conditioning events, modeling experiences, and/or informational learning do not necessarily give rise to phobic fears.

Origins of childhood fears: an evaluation of Rachman's theory of fear acquisition

This study explored Rachman's (1977) theory of fear acquisition in a large sample of Australian and American children and adolescents. Participants completed a questionnaire that addressed different pathways of fear acquisition for 10 highly prevalent fears. The majority of children attributed the onset of their fears to vicarious and instructional factors, although these indirect sources of fear were often combined with direct conditioning experiences. Also examined were effects for gender, age, and nationality. Boys and preadolescents were found to report more direct and vicarious experiences than girls or adolescents. Effects due to nationality were minimal. Methodological limitations attendant to self-reports were acknowledged.

Acquisition of blood and injection phobia and anxiety response patterns in clinical patients

The ways in which blood phobics (N = 81) and injection phobics (N = 56) had acquired their phobias were retrospectively investigated. The patients were required to answer a questionnaire concerning: (a) the origin of the phobia, with items relevant for conditioning experiences, vicarious experiences and experiences of negative information/instruction; (b) physiological reactions; (c) anticipatory anxiety; and (d) negative thoughts while in the phobic situation. In addition background data on marital and occupational status, family history of phobia, fainting history, and severity of the phobia were obtained. Furthermore, the patients' behavioral, physiological, and cognitive-subjective reactions during the behavioral test were assessed. The results showed that a majority (52%) of the patients attributed the onset of their phobias to conditioning experiences, while 24% recalled vicarious experiences, 7% instruction/information and 17% could not remember any specific onset circumstances. There was no significant relationship between ways of acquisition and anxiety components, nor did conditioning and indirectly acquired phobias differ in severity.

Conditioning experiences and phobias

A retrospective study was conducted to examine the extent to which phobias are associated with a conditioning pathway to fear. The Phobic Origin Questionnaire (Ost and Hugdahl, Behav. Res. Ther. 19, 439-477, 1981) was administered to a sample of 91 phobic outpatients (patients with panic disorder with agoraphobia, social phobics, simple phobics). Results show clearly that conditioning experiences occur more frequently than either vicarious or informational, learning experiences, which confirms the findings previously reported by Rimm, Janda, Lancaster, Nahl and Dittmar (Behav. Res. Ther. 15, 231-238, 1977) and by Ost and Hugdahl (1981; Behav. Res. Ther. 21, 623-631, 1983). Yet, conditioning experiences consist mainly of panic attacks in confirmed environments. The findings also suggest that a considerable number of phobias are based on a combination of different pathways to fear.