Pathways to spider phobia

Augmenting exposure therapy with pre-extinction fear memory reactivation and deepened extinction: A randomized controlled trial

BACKGROUND

Pre-extinction fear memory reactivation (PE-FMR) and deepened extinction (DE) enhance long-term extinction of shock-conditioned fear, and may also enhance long-term extinction of naturally acquired fear. Preliminary data suggest that PE-FMR may additionally boost the speed of fear reduction during exposure therapy.

DESIGN

Randomized controlled trial, factorial design.

METHODS

Participants with elevated fears of either spiders or snakes were randomized to (1) exposure therapy alone (n = 41), (2) exposure therapy + PE-FMR (n = 42), (3) exposure therapy + DE (n = 41), or (4) exposure therapy + PE-FMR + DE (n = 42). Participants were assessed at baseline, post-treatment, and one-week follow-up on subjective and behavioral indices of phobia. Because treatment length was tailored to speed of fear reduction, survival analyses were used to examine the speed of fear reduction during treatment.

RESULTS

DE did not improve clinical outcomes at post-treatment or follow-up, whereas PE-FMR produced more rapid fear reduction and was able to achive equivalent outcomes even when the duration of exposure therapy (tailored to speed of fear reduction) was shortened by an average of 21%.

CONCLUSIONS

Data suggest that PE-FMR is a promising strategy for reducing the overall duration of exposure-based therapies.

CLINICAL TRIAL REGISTRATION

(clinicaltrials.gov)NCT02160470.

The Spread of Fear: Symbolic Generalization Mediates Graded Threat-Avoidance in Specific Phobia

Overgeneralization of fear and threat-avoidance represents a formidable barrier to successful clinical treatment of anxiety disorders. While stimulus generalization along quantifiable physical dimensions has been studied extensively, less consideration has been given to symbolic generalization, in which stimuli are indirectly and arbitrarily related. The present study examined whether the magnitude and extent of symbolic generalization of threat-avoidance and threat-beliefs differed between spider-phobic and nonphobic individuals. Initially, participants learned two sets of stimulus equivalence relations (A1 = B1 = C1; A2 = B2 = C2). Next, one cue (B1) was established as a conditioned stimulus (CS +; threat) that signalled onset of spider images and prompted avoidance, and another cue (B2) was established as a CS– (safety cue) that signalled the absence of such images. Subsequent testing showed that phobics compared to nonphobics exhibited greater symbolic generalization of threat-avoidance to threat cues A1 and C1 (indirect CS+ threat cues related via symmetry and equivalence, respectively), while all individuals showed nonavoidance to indirect safety cues A2 and C2. The enhanced symbolic generalization of threat-beliefs and avoidance behaviour observed in spider phobics warrants further investigation.

Safe from harm: learned, instructed, and symbolic generalization pathways of human threat-avoidance

Avoidance of threatening or unpleasant events is usually an adaptive behavioural strategy. Sometimes, however, avoidance can become chronic and lead to impaired daily functioning. Excessive threat-avoidance is a central diagnostic feature of anxiety disorders, yet little is known about whether avoidance acquired in the absence of a direct history of conditioning with a fearful event differs from directly learned avoidance. In the present study, we tested whether avoidance acquired indirectly via verbal instructions and symbolic generalization result in similar levels of avoidance behaviour and threat-beliefs to avoidance acquired after direct learning. Following fear conditioning in which one conditioned stimulus was paired with shock (CS+) and another was not (CS-), participants either learned or were instructed to make a response that cancelled impending shock. Three groups were then tested with a learned CS+ and CS- (learned group), instructed CS+ (instructed group), and generalized CS+ (derived group) presentations. Results showed similar levels of avoidance behaviour and threat-belief ratings about the likelihood of shock across each of the three pathways despite the different mechanisms by which they were acquired. Findings have implications for understanding the aetiology of clinical avoidance in anxiety.

Understanding emotion: lessons from anxiety

We agree that conceptualisation is key in understanding the brain basis of emotion. We argue that by conflating facial emotion recognition with subjective emotion experience, Lindquist et al. understate the importance of biological predisposition in emotion. We use examples from the anxiety disorders to illustrate the distinction between these two phenomena, emphasising the importance of both emotional hardware and contextual learning.

The role of verbal threat information in the development of childhood fear. "Beware the Jabberwock!"

Rachman's (Behaviour Research and Therapy 15:372-387, 1977; Clinical Psychology Review 11:155-173, 1991) three pathways theory proposed that childhood fears not only arise as a consequence of direct learning experiences, but can also be elicited by means of threat information transmission. This review looks at the scientific evidence for this idea, which has accumulated during the past three decades. We review research on the influences of media exposure on children's fears, retrospective parent and child reports on the role of threat information in fear acquisition, and experimental studies that explored the causal effects of threat information on childhood fears. We also discuss possible mechanisms by which threat information exerts its influence and the processes relevant to understand the role of this type of learning experience in the origins of fear. Finally, implications for the prevention and intervention of childhood fears are briefly explored, and potential leads for future research will be highlighted.

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.

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.

The effect of UCS inflation and deflation procedures on 'fear' conditioning

Davey (1992: Classical conditioning and the acquisition of human fears and phobias: a review and synthesis of the literature. Advances in Behaviour Research and Therapy, 14, 29-66) hypothesized that subjective revaluation of an unconditioned stimulus (UCS) would determine the strength of the autonomic conditioned response (CR) in the fear conditioning paradigm. The purpose of the present study was to examine the effect of UCS aversiveness on the CR strength in the fear conditioning paradigm. The UCS aversiveness was controlled by the UCS intensity; that is, the UCS intensity was increased for the inflation group or decreased for the deflation group. Thirty subjects were randomly assigned to the inflation or the deflation group, and they participated under both experimental and control conditions. All subjects went through the pretest, the acquisition of classical conditioning, the UCS intensity operation, and the test sessions. The indices of the CR were skin conductance responses (SCRs) and a subjective aversion to the conditioned stimulus (CS). The main results were as follows. (1) The CR strength measured by SCR was increased by the UCS inflation and decreased by the UCS deflation. (2) The subjective aversiveness of the CS was not sensitive to both manipulations of UCS intensity. These results suggested that the autonomic CR strength might be influenced by the subjective revaluation of UCS, as Davey (1992) described. The result from the test of the subjective aversiveness of the CS, however, could not support Davey's model. The difference between expressions of the SCR and the subjective aversiveness of the CS might be caused by different learning systems.

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; Ost, 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.

Stability of driving fear acquisition pathways over one year

The present study was conducted in response to increasing concerns about the potential unreliability of retrospective accounts in assessing the origins of fears and phobias. Some investigators [e.g. Menzies, R.G., & Clarke, J.C. (1993). The etiology of fear of heights and its relationship to severity and individual response patterns. Behaviour Research and Therapy, 31, 355-365; Kirkby, K.C., Menzies, R.G., Daniels, B.A., & Smith, K.L. (1995). Aetiology of spider phobia: Classificatory differences between two origins instruments. Behaviour Research and Therapy, 33, 955-958; King, N.J., Gullone, E., & Ollendick, T.H. (1998). Etiology of childhood phobias: current status of Rachman's three pathways theory. Behaviour Research and Therapy, 36, 297-309.] have questioned the reliability of retrospective reports at a single assessment point, although the test-retest reliability of such accounts has yet to be examined. The aim of the present study was to conduct a one-year follow-up of the subclinical driving-fearful sample studied by Taylor and Deane [Taylor, J. E., & Deane, F. P. (1999). Acquisition and severity of driving-related fears. Behaviour Research and Therapy, 37, 435-449.] to primarily investigate, the stability of fear onset ascriptions and fear severity over time. 85 respondents completed a questionnaire which assessed fear origins, anxiety response patterns, and additional fear-relevant events occurring over the year. The results suggest that retrospective accounts of fear onset may be quite unstable over time, although this instability does not clearly appear to be related to intervening events, and limitations of the study make these results inconclusive. Fear-relevant negative thinking worsened over time, while physiological reactions and general anxiety remained relatively stable. The theoretical, methodological and clinical implications of the findings are discussed, along with suggestions for future research.

Recall and validation of phobia origins as a function of a structured interview versus the Phobia Origins Questionnaire

Memory for fear onset events was examined in 43 dog-fearful and 48 blood/injection-fearful participants. Half of each fear type was administered the Phobia Origins Questionnaire (POQ), and half the Phobia Origins Structured Interview (POSI). Written accounts of recalled onset experiences were sent to participants' parents for verification. More participants assessed by the POQ reported a phobia onset event (93%) than did those assessed by the POSI (54%). A majority in both methods recalled conditioning-like experiences. The POQ resulted in more reports of vicarious and informational onset reports than did the POSI. Parents confirmed more onset event reports obtained by the POSI (81%) than those obtained by the POQ, (50%). In addition, in 21% of cases where a child recalled an event, a parent reported an onset event that predated the one provided by the child. Results are discussed in terms of memory mechanisms operative in autobiographical memories.

The etiology of childhood spider phobia

Twenty-six girls with a clinical spider phobia and 26 matched control girls were interviewed about conditioning, modeling, and negative information experiences in connection with spiders. In addition, parents of the phobic girls were independently interviewed about the origins of their child's phobia. Phobic children more often reported aversive conditioning experiences with spiders than did control children. Also, in a number of cases, conditioning events described by the phobic children were confirmed by their parents, a result that replicates the findings of Merckelbach, Muris and Schouten (1996; Behaviour Research and Therapy, 34, 935-938). Taken together, the results contradict a strong version of the non-associative account of phobias and suggest that in at least some cases, conditioning events may contribute to the development of (childhood) spider phobia.

Parental history, aversive exposure and the development of snake and spider phobia in women

Parental history and experiential factors in the development of snake and spider phobia were studied. Phobic women (DSM-IV, n = 158) reported on family history of animal phobia and whether direct (being frightened by the phobic object) or indirect (seeing someone else being frightened by and/or being warned of the phobic object) fear exposure predated phobia development. Fifty-nine mothers (37%) and 11 fathers (7%) had snake or spider phobia, which is higher than the upper 95% confidence interval in the populations (Fredrikson, Annas, Fischer & Wik, Behavior Research and Therapy, 34, 33-39). Lifetime Relative Risk, RR, of animal phobia in probands' mother and fathers as a function of at least one phobic grandparent was 3.3 and 13.7 respectively. Indirect fear exposures were more common in snake (45%) than spider (27%) phobics (RR = 1.4). Indirect fear exposures were more common among probands with a positive parental history, the RRs being 3.6 and 2.1 as a function of maternal and paternal family history. Direct exposures were unrelated to parental history. The familial resemblance and transmission of specific phobia could be experiential in origin mediated by indirect exposures or of hereditary origin mediated by genetic factors. It may represent genetically facilitated learning and exemplify imprinting in humans.

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.

Vulnerability representation: the role of perceived dangerousness, uncontrollability, unpredictability and disgustingness in spider fear

It was proposed that cognitive vulnerability representations relating to the perceived uncontrollability, unpredictability, dangerousness and disgustingness of spiders are important factors in the fear of spiders. One-hundred and ninety-two first-year psychology students completed a questionnaire measuring the four vulnerability variables, spider fear and learning history. It was found that fear of spiders was highly correlated with each of the four vulnerability variables. In addition, greater fear of spiders was found for females in comparison with males and this was associated with differential perceptions of spiders as uncontrollable, unpredictable, dangerous and disgusting. Finally, the vulnerability variables accounted for significantly more variance in fear scores than the experience of a number of classical conditioning, vicarious and informational learning events. It is argued that there is value in considering a person's perception of the uncontrollability, unpredictability, dangerousness and disgustingness of spiders in order to better understand individual differences in spider fear.

UCS inflation and human aversive autonomic conditioning

Fifty students participated in a differential conditioning paradigm. In the first part of the experiment, one neutral slide (CS+) was paired with a tone (UCS) and another neutral slide (CS-) was never followed by a tone. During the subsequent inflation phase, unsignalled UCSs gradually increased in strength for the inflation group while they were kept constant for the control group. During extinction trials, the inflation group initially showed relatively stronger UCS expectancies on the CS+ trials than the control group. In contrast to what was predicted, the UCS inflation procedure did not result in stronger conditioning effects of the skin conductance response compared to the control procedure. The effectiveness of the UCS inflation procedure was not related to trait anxiety.

Spider phobia questionnaire for children (SPQ-C): a psychometric study and normative data

The purpose of this study was to develop a reliable and valid questionnaire to assess spider fear in children. The Spider Phobia Questionnaire for adults was adapted for children by simplifying items and by assessing situations relevant to children. The SPQ for children (SPQ-C) was administered to two non-clinical samples of children aged 8-12. The first sample consisted of 586 Ss who filled in the SPQ-C twice, with a retest interval of 6-7 weeks. Internal consistency and test-retest reliability were high. The second sample consisted of 669 children of which 28 spider phobic and 30 nonphobic girls were selected for the Behavioural Approach Test (BAT). The SPQ-C predicted BAT scores, thus supporting the validity of the questionnaire as a measure of spider fear. Norms for the SPQ-C, based on the total sample of children, are provided.

Computerized exposure and in vivo exposure treatments of spider fear in children: two case reports

Two spider phobic children were first given a computerized exposure treatment, and then received exposure in vivo. The cases provided no evidence for the effectiveness of the computerized exposure treatment. Exposure in vivo was found to be very successful, resulting in substantial reduction of self-reported spider fear and clear improvement on the behavioral avoidance test.

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.

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.