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.     

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 (Öst 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 phobies). 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 Öst and Hugdahl (1981; Behav. Res. Ther. 21, 623–631, 1983). Yet, conditioning experiences consist mainly of panic attacks in confined environments. The findings also suggest that a considerable number of phobias are based on a combination of different pathways to fear.     

Learning history in fear of blushing

Two studies, investigating the learning history (i.e. traumatic conditioning experiences, vicarious learning, informational learning) of individuals with and without fear of blushing, are presented. In study 1, individuals high (n=61) and low (n=59) in fear of blushing completed the (revised) Phobic Origin Questionnaire [POQ; Öst, L. G., & Hugdahl, K. (1981). Acquisition of phobias and anxiety response patterns in clinical patients. Behavior Research and Therapy, 19, 439–447]. In study 2, individuals who applied for treatment for fear of blushing (n=31) and a nonfearful, matched control group (n=31) were interviewed with the same instrument, taking into account only specific memories. High fearful individuals reported more negative learning experiences in connection with blushing than low fearful individuals, irrespective of the type of questioning. Meanwhile, study 1 (written POQ) produced higher percentages of negative learning experiences for both high and low fearful individuals than study 2 (interview). It is concluded that the POQ interview showed a more realistic picture than the written POQ. The possible role of learning history in the acquisition of fear of blushing is discussed.     

Acquisition of agoraphobia, mode of onset and anxiety response patterns

The ways in which 80 agoraphobic patients had acquired their phobia were investigated. The patients were requested 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; (d) negative thoughts while in the phobic situation. In addition, data on mode of onset, precipitating factors, family history of phobias, marital and occupational status and severity of the phobia were obtained. The reported anxiety reaction was conceptualized in terms of the Three-Systems Model of fear and anxiety, i.e. anxiety as composed of a physiological, cognitive and behavioral component. The results showed that a large majority (81%) of the patients attributed their phobias to conditioning experiences, while 9% recalled vicarious learning, none recalled instruction/information and 10% could not recall any specific onset circumstances at all. In another classification 46% of the patients had a rapid, 36% a gradual and 18% a slow onset of their phobias. There was no relationship between either the ways of acquisition, or the modes of onset, and the anxiety components, nor did the conditioning and the indirect groups differ in severity of phobic reactions.     

Acquisition of phobias and anxiety response patterns in clinical patients

The ways in which phobic patients (N = 106; animal-, social- and claustrophobics) acquired their phobias were investigated in the present study. The results showed that a large majority (58%) of the patients attributed their phobias to conditioning experiences, while 17% recalled vicarious experiences, 10% instructions/information and 15% could not recall any specific onset circumstances. There was no clearcut relationship between the ways of acquisition and anxiety components (subjective, behavioral, physiological), nor did the conditioning and indirectly acquired phobias differ in severity. However, some interesting trends emerged in the data, showing that animal phobics who recalled conditioning experiences to a larger extent also responded physiologically. For patients with indirect onset experiences (for all three types of phobias) the reverse was true, i.e. they responded to a larger extent in a cognitive-subjective way, rather than with increased physiological arousal.     

Pathways to fear in spider phobic children

Twenty-two children with spider phobia were interviewed about the origins of their fear. More specifically, children were asked about conditioning events, modeling experiences, and negative information transmission. To evaluate the reliability of the information provided by the children, parents were independently interviewed about the origins of their children's phobias. While 46% of the children claimed to have always been afraid, 41% ascribed the onset of their fear to aversive conditioning events. The large majority of these events were confirmed by parents. These findings cast doubts on a strong version of the non-associative account of spider phobia, i.e. the idea that spider phobia is acquired in the complete absence of learning experiences.     

Children's nighttime fears: parent-child ratings of frequency, content, origins, coping behaviors and severity

The present study investigated nighttime fears in normal school children aged 4 to 12 yr (N=176). Children and their parents were interviewed about the frequency, content, origins, coping behaviors and severity of children's nighttime fears. Results showed that 73.3% of the children reported nighttime fears, indicating that these fears are quite prevalent. Inspection of the developmental course of nighttime fears revealed that these fears are common among 4- to 6-year-olds, become even more frequent in 7- to 9-year-olds and then remain relatively stable in 10- to 12-year-olds. Inspection of the origins of nighttime fears revealed that most of the children (i.e., almost 80%) attributed their fear to negative information; conditioning and modeling were endorsed less frequently (25.6% and 13.2%, respectively). A substantial percentage of the children (24.0%) indicated that learning experiences had not played a role in the acquisition of their nighttime fears. Children reported a variety of coping strategies in order to deal with their nighttime fears and generally rated these strategies as helpful in reducing anxiety. Furthermore, children's nighttime fears were associated with moderate levels of anxiety. Moreover, in about 10% of the children, nighttime fears were related to one or more DSM-III-R anxiety disorders. Finally, parental reports of children's nighttime fears substantially deviated from children's reports. Most importantly, parents provided a marked underestimation of the frequency of nighttime fears, at least as reported by their children.     

Origins of fear of dogs in adults and children: the role of conditioning processes and prior familiarity with dogs.

One hundred adults and 30 children completed questionnaires to investigate fear of dogs. Dog fearful adults asked to recall the origins of their fear reported classical conditioning experiences more frequently than vicarious acquisition or informational transmission. Overall, however, there was no difference in the frequency of attacks reported by the fearful and non-fearful groups. Significantly more fearful than non-fearful adults reported little contact with dogs prior to the onset of their fear which suggests that early non-eventful exposure to dogs may prevent a conditioning event from producing a dog phobia. Most adults reported that their fear began in childhood, and dog fear were more frequently reported by children than by adults. In the aggregate, however, dog-fearful adults and children differed in several ways; children were more likely than adults to report having received warnings about dogs, but also to recognize the potential attractiveness of a friendly dog. Unlike dog-fearful children, dog-fearful adults reported many other fears in addition to their fear of dogs. A better understanding of fear of dogs in adults may depend on discovering why some dog-fearful children, but not others, apparently lose their fear of dogs as they become older.     

The origins of fear of snakes

In the present study, a questionnaire about the nature and origin of fear of snakes was administered to 60 Phobic, 82 Low Fear and 35 High Fear college students. Phobic and High Fear subjects reported greater fear on a variety of components of snake fear. There was little evidence supporting the role of direct conditioning experiences in the acquisition of fear of snakes. Rather, the results suggested a variety of observational and instructional learning experiences as related to the acquisition of snake fear. Although preparedness for direct conditioning does not seem relevant, a preparedness for observational and instructional learning is possible.     

Re-examining the effects of verbal instructional type on early stage motor learning

The present study investigated the differential effects of analogy and explicit instructions on early stage motor learning and movement in a modified high jump task. Participants were randomly assigned to one of three experimental conditions: analogy, explicit light (reduced informational load), or traditional explicit (large informational load). During the two-day learning phase, participants learned a novel high jump technique based on the ‘scissors’ style using the instructions for their respective conditions. For the single-day testing phase, participants completed both a retention test and task-relevant pressure test, the latter of which featured a rising high-jump-bar pressure manipulation. Although analogy learners demonstrated slightly more efficient technique and reported fewer technical rules on average, the differences between the conditions were not statistically significant. There were, however, significant differences in joint variability with respect to instructional type, as variability was lowest for the analogy condition during both the learning and testing phases, and as a function of block, as joint variability decreased for all conditions during the learning phase. Findings suggest that reducing the informational volume of explicit instructions may mitigate the deleterious effects on performance previously associated with explicit learning in the literature.     

Learning Experiences and Anxiety Sensitivity in Normal Adolescents

The present study examined the relationships between learning experiences with respect to somatic symptoms and levels of anxiety sensitivity in youths. Fifty-two normal adolescents aged 12 to 14 years were interviewed about their learning experiences with anxiety-related and nonanxiety-related somatic symptoms and completed the Childhood Anxiety Sensitivity Index. Results showed that informational learning to some extent contributed to adolescents' anxiety sensitivity levels. That is, parents' transmission of the idea that somatic symptoms might be dangerous was significantly associated with levels of anxiety sensitivity. Other learning experiences such as parental reinforcement or observational learning were not found to be related to anxiety sensitivity. It can be concluded that learning experiences seem to play a small but significant role in the development of high levels of anxiety sensitivity.     

Ways of acquiring phobias and outcome of behavioral treatments

The way of acquisition of phobias was studied in relation to different behavioral treatments for phobias. Ss (N = 183) were clinical patients belonging to six different phobic groups (agoraphobics, claustrophobics, social phobics, animal phobics, blood phobics and dental phobics), and the treatments were categorized as behaviorally focused (exposure in vivo and social-skills training), physiologically focused (systematic desensitization and applied relaxation) and cognitively focused (self-instruction training and fading). Results showed that both for patients with direct conditioning experiences and indirect acquisition those treated with behavioral and physiological methods improved more than those receiving cognitive methods when looking at the change-score data. Regarding the proportion of clinically improved patients there was no difference between treatments among the Ss with a background of conditioning experiences. In the group with indirect acquisition, on the other hand, the cognitive methods were more effective.     

Contingency awareness in a symptom learning paradigm: necessary but not sufficient?

In previous studies, we found that bodily symptoms can be learned in a differential conditioning paradigm, using odors as conditioned stimuli (CSs) and CO2-enriched air as unconditioned stimulus (US). However, this only occurred when the odor CS had a negative valence (a selective conditioning effect), and tended to be more pronounced in persons scoring high for Negative Affectivity (NA). This paper considers the necessity and/or sufficiency of awareness of the CS-US contingency in three studies using this paradigm. The relation between contingency awareness and the selective conditioning effect, and between contingency awareness and NA was also considered. Both self reported symptoms and respiratory physiology served as dependent variables. A learning effect on symptoms was found only for participants aware of the CS-US contingency, but not all participants reporting contingency awareness showed a learning effect. No conditioning effects appeared on the physiological measures. Also contingency awareness did not account for the selective conditioning effect, and did not interact with NA. Overall, the necessity but insufficiency hypotheses can only be withhold for group data and not for individual data.     

The etiology of specific fears and phobias in children: a critique of the non-associative account

The non-associative account of phobic etiology assumes that a number of specific fears (e.g., fear of heights, water, spiders, strangers, and separation) have an evolutionary background and may occur in the absence of learning experiences (e.g., conditioning). By this view, these specific fears pertain to stimuli that once posed a challenge to the survival of our prehistoric ancestors. Accordingly, they would emerge spontaneously during the course of normal development and only in a minority of individuals, these specific fears would persist into adulthood. While the non-associative approach has generated interesting findings, several critical points can be raised. First, it capitalizes on negative findings, i.e., the failure to document learning experiences (e.g., conditioning, modeling) in the history of phobic children. Second, it largely ignores factors that have been found to be crucial for the acquisition of early childhood fears (e.g., the developmental level of the child, stimulus characteristics such as novelty, aversiveness, and unpredictability, and early experience with uncontrollable events). As an alternative to the non-associative account, we briefly describe a multifactorial model of childhood fears and phobias.     

Elevated disgust sensitivity in blood phobia

In order to demonstrate elevated disgust sensitivity and facilitated disgust learning in patients suffering from blood injection injury phobia, 23 phobics and 20 controls underwent an evaluative conditioning experiment. They were presented with picture pairs consisting of affectively neutral pictures (CS), which were followed by either disgust-inducing, fear-inducing, pleasant, or neutral scenes (US). During the presentation we recorded the electromyogram (EMG) of the musculus levator labii as a specific disgust indicator. Affective ratings for the pictures were determined before and after conditioning. Also, CS-US contingency verbalisation (CV) was assessed. Phobics reported a greater overall disgust sensitivity, experienced stronger feelings of disgust, and showed greater EMG responses while viewing disgust-eliciting scenes than control subjects. Evaluative conditioning occurred equally in both groups and depended on CV.     

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.     

Human evaluative conditioning: acquisition trials, presentation schedule, evaluative style and contingency awareness.

Two different processes may be operative in human Pavlovian conditioning: signal learning and evaluative learning. Whereas most studies on evaluative conditioning focused on a mere demonstration of the phenomenon or on a theoretical analysis of the underlying processes, some basic parameters of evaluative learning are still unexplored. Hence, using the standard neutral picture--(dis)liked picture pairing paradigm (Baeyens, Eelen & Van den Bergh, 1990), in this study the effect of two parameters of evaluative conditioning was assessed on a between-subjects base, namely the Number of Acquisition Trials (2/5/10/20) and the Presentation Schedule of the stimulus pairs (blockwise or random). Additionally, the study included an exploratory analysis of the potential effects of the Evaluative Style of subjects (Feelers vs Thinkers, operationalized in terms of speed of emitting evaluations). Finally, the relationship between contingency awareness and evaluative learning was reassessed. Neutral-liked conditioning was found to be quadratically related to the number of acquisition trials (increase in effect up to 10 trials, decrease from 10 to 20 trials), whereas neutral-disliked conditioning linearly increased with increasing numbers of trials. Randomized vs blockwise presentation schedules of the stimulus pairs did differentially affect the overall pattern of conditioning, but in a way which was both unexpected and difficult to account for theoretically. Both the Evaluative Style of subjects and contingency awareness were demonstrated to be generally orthogonal to conditioned shifts in CS valence. Based on these findings, some practical suggestions are provided for the application of evaluating conditioning based therapeutical interventions to affective-behavioral disorders which are centred around inappropriate (dis)likes.     

Heart Rate Reactivity in HAD and LAD Rats during Pavlovian Fear Conditioning

Recently, we reported that High-Alcohol-Drinking (HAD) rats exhibited selective deficits in active avoidance learning under alcohol-naive conditions, and that administration of moderate doses of alcohol (0.5 and 1.0 g/kg) facilitated learning in these rats (Blankenship et al., 2000; Rorick et al., 2003b). We hypothesized that the deficits resulted from excessive fear in the aversive learning context and that the anxiolytic properties of alcohol may have contributed to the improved learning that was observed after alcohol administration. This hypothesis was supported by a recent study in which prolonged freezing in HAD rats was seen after a classical fear conditioning procedure (Rorick et al., 2003a). To provide additional evidence that HAD rats indeed exhibit behaviors consistent with the expression of increased fear in aversive learning contexts, we employed a Pavlovian fear conditioning task to measure heart rate in HAD and Low-Alcohol-Drinking (LAD) rats. In this study, HAD (HAD-1 and HAD-2) and LAD (LAD-1 and LAD-2) rats were assigned to one of three pre-exposure conditions: Context Only, Context/Tone, or Sequential (Context Only followed by Context/Tone) Pre-Exposure. Following pre-exposure, fear conditioning acquisition and extinction procedures were identical for all groups. Results indicated that although no baseline differences were observed between HAD and LAD rats, HAD rats receiving Context-Only pre-exposure exhibited excessive heart rate reactivity to the tone conditional stimulus during fear conditioning acquisition, compared to LAD rats receiving the same pre-exposure conditions. These findings support the hypothesis that HAD rats exhibit behaviors consistent with increased fear in aversive learning contexts, as measured by autonomic conditioning.     

Acquisition of blood, injury, and needle fears and phobias

The origins of fear and phobia of blood, injury, and injections were investigated in a sample of 128 fearful university students. Based on Mutilation Questionnaire scores, subjects were designated as common fear, high fear, or phobic. Ss reports of their onset experiences obtained from structured interviews were categorized into one or more acquisition pathways of conditioning, vicarious observation, and information. Of the 73% of Ss who recalled one or more onset experiences, 76% reported conditioning-like events as the primary pathway with the majority reporting fear-related UCSs. Vicarious experiences were reported as primary by 20% and 3% reported information as being primary in their fear onset. Severity of fear was unrelated to the pathway by which it was acquired, to whether the onset was recalled, and if recalled, whether it was due to a single or to multiple traumatic events. Results are discussed in terms of methodological problems of memory issues and means by which data are collected.     

Heart rate reactivity in HAD and LAD rats during Pavlovian fear conditioning

Recently, we reported that High-Alcohol-Drinking (HAD) rats exhibited selective deficits in active avoidance learning under alcohol-naive conditions, and that administration of moderate doses of alcohol (0.5 and 1.0 g/kg) facilitated learning in these rats (Blankenship et al., 2000; Rorick et al., 2003b). We hypothesized that the deficits resulted from excessive fear in the aversive learning context and that the anxiolytic properties of alcohol may have contributed to the improved learning that was observed after alcohol administration. This hypothesis was supported by a recent study in which prolonged freezing in HAD rats was seen after a classical fear conditioning procedure (Rorick et al., 2003a). To provide additional evidence that HAD rats indeed exhibit behaviors consistent with the expression of increased fear in aversive learning contexts, we employed a Pavlovian fear conditioning task to measure heart rate in HAD and Low-Alcohol-Drinking (LAD) rats. In this study, HAD (HAD-1 and HAD-2) and LAD (LAD-1 and LAD-2) rats were assigned to one of three pre-exposure conditions: Context Only, Context/Tone, or Sequential (Context Only followed by Context/Tone) Pre-Exposure. Following pre-exposure, fear conditioning acquisition and extinction procedures were identical for all groups. Results indicated that although no baseline differences were observed between HAD and LAD rats, HAD rats receiving Context-Only pre-exposure exhibited excessive heart rate reactivity to the tone conditional stimulus during fear conditioning acquisition, compared to LAD rats receiving the same pre-exposure conditions. These findings support the hypothesis that HAD rats exhibit behaviors consistent with increased fear in aversive learning contexts, as measured by autonomic conditioning.