Overprediction of anxiety, and disconfirmatory processes, in anxiety disorders

Responses conditioned to fear-relevant stimuli survive extinction of the expectancy of the UCS

Davey suggests that increased resistance to extinction of CRs conditioned to fear-relevant stimuli may be due to more persistent expectancies of the UCS following these stimuli. However, this viewpoint is contradicted by existing empirical evidence that fear-relevant CRs survive an extinction trials series producing extinction of expectancies whereas CRs conditioned to non-fear-relevant CSs do not.

Eggs in more than one basket: Mediating mechanisms between evolution and phobias

The evolutionary origin of phobias is strongly supported by behavioral genetics and monkey vicarious conditioning data. Prepared Pavlovian conditioning may be only one of the mechanisms mediating the evolutionarily determined outcome in phobias, avoidance. Davey's alternative biased expectancy hypothesis has merit in accounting for some aspects of laboratory data, but it is insufficient to explain the unconscious origin of phobic fear.

Preparedness, phobias, and the Panglossian paradigm

In his critique of preparedness theory, Davey does not address the limitations of adaptationism. The purpose of this commentary is to outline problems that arise when one assumes that mental illness (e.g., phobic disorder) must have had adaptive significance for it to have survived the vicissitudes of natural selection.

Natural selection and fear regulation mechanisms

Expectations can facilitate rapid fear conditioning and this may explain some phenomena that have been attributed to preparedness. However, preparedness remains the best explanation for some aspects of clinical phobias and the difficulty of creating fears of modern dangers. Rapid fear conditioning based on expectancy is not an alternative to an evolutionary explanation, but has, like preparedness, been shaped by natural selection.

Innateness versus expectation in human fears: Causal versus maintaining factors?

This commentary focuses upon two issues raised by Davey's target article: (1) whether there are certain core features of stimuli we learn to fear, rather than specific types of objects or situations, which implies some element of innateness; and (2) whether expectancy biases serve to maintain rather than generate anxiety.

Expectancy bias as sole or partial account of selective associations?

Davey reviews evidence purporting to distinguish between two accounts of selective associations – expectancy bias and evolved predispositions, although these hypotheses largely apply to different levels of causal analysis. Criticisms of primate studies in which subjects lack prior exposure to stimuli seem uncompelling. Expectancies may sometimes serve as proximal mediators in selective associations, but other factors, both proximate and ultimate, are clearly also involved.

The uneven distribution of fears and phobias: A nonassociative account

A review of data concerning the uneven distribution of phobias suggests that nonassociative, ethological models can account for most of tile important findings that cannot be attributed to expectancy biases. The origin of a variety of fears that appear in fixed developmental patterns across divergent cultures and species can best be explained by biological models.

Preparedness and phobias: Specific evolved associations or a generalized expectancy bias?

Most phobias are focussed on a small number of fear-inducing stimuli (e.g., snakes, spiders). A review of the evidence supporting biological and cognitive explanations of this uneven distribution of phobias suggests that the readiness with which such stimuli become associated with aversive outcomes arises from biases in the processing of information about threatening stimuli rather than from phylogenetically based associative predispositions or “biological preparedness.” This cognitive bias, consisting of a heightened expectation of aversive outcomes following fear-relevant stimuli, generates and maintains robust learned associations between them. Some of the features of such stimuli which determine this expectancy bias are estimates of how dangerous they are, the semiotic similarity between them and their aversive outcomes, and the degree of prior fear they elicit. Ontogenetic and cultural factors influence these features of fear-relevant stimuli and are hence important in determining expectancy bias. The available evidence does not exclude the possibility that both expectancy biases and specific evolved predispositions coexist, but the former can explain a number of important findings that the latter cannot.

A stochastic optimality theory of preparedness and plasticity

Many now consider “instinct” and “learning” opposite poles of a unidimensional continuum. An alternative model with two independently varying parameters predicts different selective pressures. Behavioral adaptation matches the organism's utilizations of stimuli and responses to their ecological validities: the mean validity over evolutionary time specifies the optimal initial potency of the prepared association; the variance specifies the optimal prepared plasticity.

An experimental test of stimulus estimation theory: danger and safety with snake phobic stimuli

The stimulus estimation model (Taylor & Rachman, 1994) asserts that fear overprediction stems from: (a) overprediction of the danger elements of a phobic stimulus, and (b) underprediction of existing safety resources. Using a 2x2 factorial design, with danger (high vs low) and safety (high vs low) as between-subjects variables, an experimental test of the model was conducted with 25 snake-fearful participants per condition. The four experimental conditions were matched on initial levels of snake fearfulness, as assessed by the Snake Questionnaire (SNAQ). For the 51 participants who demonstrated overprediction of fear, high danger led to reliably more fear overprediction than low danger; and low safety led to reliably more fear overprediction than high safety. The interaction between danger and safety was not statistically significant. The results offer the first convincing experimental support for the stimulus estimation model of fear overprediction.

Assessing the perceived predictability of anxiety-related events: a report on the perceived predictability index

Predictability, or lack thereof, is believed to play a critical role in the development and maintenance of anxiety, with unpredictability being associated with heightened levels of anxious and fearful responding. Despite the potential importance of predictability in theoretical accounts of emotional dysregulation, currently no standardized assessment instrument exists to assess predictability perceptions for anxiety-related events. The present series of four investigations report on an initial attempt to develop a self-report instrument (i.e., Perceived Predictability Index, PPI) that can measure predictability perceptions for the occurrence, duration, and termination of anxiety-related events. Initial item selection and factor structure of the instrument was based on a large sample of participants and yielded a two-factor solution: (1) prediction of anxiety-related environmental events and (2) prediction of internal events. Our subsequent studies show that the PPI possesses adequate levels of internal consistency and temporal stability over time. Additionally, the PPI demonstrated adequate divergent and convergent validity relative to other standard anxiety and fear measures. The internal dimension of the scale also demonstrated predictive validity for emotional responding during a biological challenge test. We discuss these findings in relation to the role of perceived predictability in the study of anxious and fearful responding, and offer directions for future research.

What do patients do with their obsessive thoughts?

Current models of Obsessive-Compulsive Disorder (OCD) accord a key role to neutralization in the maintenance of obsessional thoughts. Although overt compulsions are well known and have frequently been described in the literature, their cognitive equivalents have not been described to any great extent. This study systemically described the repertoire of strategies used by 29 OCD patients with dominant obsessive thoughts. Extensive repertoires were reported, characterized by low to moderate mean efficacy in removing the thoughts. The majority of strategies were not cognitive rituals nor neutralization in the narrow sense of 'attempts at putting right', even though they were effortful, intentional, and deployed in a strategic way. The results are discussed in terms of the need for a broad definition of neutralization that includes all strategies including coping strategies. Clinical implications are discussed and comprehensive response prevention is recommended for the treatment of obsessive thoughts.

Why do people tend to overpredict pain? On the asymmetries between underpredictions and overpredictions of pain

After an underpredicted painful experience people tend to expect increased pain levels for a considerable time, despite disconfirmatory experiences. Underpredictions also tend to raise long-lasting fear and increased physiological responding. Overpredicted pain does not have such dramatic effects. What are the reasons for this asymmetry? Evidence for and against the hypothesis that underpredicted pain hurts more than correctly predicted pain, and that overpredictions result from a tendency to avoid the extra aversiveness of underpredictions, is reviewed. Based on recent experiments this explanation is rejected, and alternative explanations are discussed. It is reasoned that the most plausible explanation is that the organism automatically infers danger from an underprediction, because of the loss of predictability into the dangerous direction (i.e. more pain). Elevated expectancy and fear levels are the result of this. A modified stimulus-comparator model that accounts for the differential effects of both types of incorrect predictions is suggested. In contrast to previous models, such a model hypothesizes: (i) differential processing of under- and overpredictions; and (ii) different processes involved in the influence of expectations on subjective and non-subjective pain responses.

"If I feel anxious, there must be danger": ex-consequentia reasoning in inferring danger in anxiety disorders

It has been suggested that neurotic patients engage in 'emotional reasoning', i.e. draw invalid conclusions about a situation on the basis of their subjective emotional response. The present experiment investigated whether anxiety patients infer danger on the basis of their anxious response, whereas normals infer danger only on the basis of objective information. Four groups of anxiety patients (52 spider phobics, 41 panic patients, 38 social phobics, and 31 other anxiety patients) and 24 normal controls made ratings of the danger they perceived in scripts in which information about objective safety vs objective danger, and anxiety response vs non-anxiety response information were systematically varied. As hypothesized, anxiety patients were not only influenced by objective danger information, but also by anxiety response information, whereas normal controls were not. The effect was neither situation-specific, nor specific for panic patients. This tendency to infer danger on the basis of subjective anxiety ('ex-consequentia reasoning') may play a role in the development and maintenance of anxiety disorders.

Stimulus estimation and the overprediction of fear: a comment on two studies

The overprediction of fear is the tendency to overestimate the amount of fear one will experience in a subjectively threatening situation. This bias is thought to promote excessive avoidance and limit the opportunity for corrective learning. The stimulus estimation model states that the overprediction of fear arises from the overprediction of the danger features of the stimulus and the underprediction of available safety resources. Two recent studies reportedly failed to support the model (Arntz, Hildebrande & van den Hout, Behaviour Research and Therapy, 32, 709-722, 1994; Telch, Valentiner & Bolte, Behaviour Research and Therapy, 32, 747-751, 1994). The present commentary shows that both studies suffered significant methodological problems and neither can be said to have tested the model. Criteria for evaluating the model are briefly discussed.

Counterevidence from psychopharmacology, psychopathology, and psychobiology

Davey's discussion of phobias is criticized because of the lack of distinctions between the various classes of phobias. Psychopharmacological evidence indicates differing pathophysiologies. Clinical psychopharmacological distinctions are not congruent with either a strict phylogenetic preparedness model or with cognitive biases. Davey's critique of the laboratory bred animal studies seems far fetched. His hypothesis concerning the importance of historical significance is clearly ad hoc rather than based on comparative data.

Heredity × environment or developmental interactions?

This commentary acknowledges the importance of Davey's biocognitive approach to the uneven distribution of fears on the basis of its contribution to a human model for understanding fear. An integrated heredity-environment and developmental transactional approach based on field/system theory is recommended in place of the mechanistic heredity × environment interactionism that Davey uses to explain behavioral ontogeny.

Nonlinear experiential influences on the development of fear reactions

Failure to find an obvious or linear relationship between a developmental experiential factor and a developmental outcome often leads investigators to posit concepts such as “biological preparedness” and “evolved predispositions” that allude to hypothetical geneticmechanisms that may not exist. However, experiential nonlinearities alone may explain the development of certain instinctive behaviors, as shown by studies on alarm call responsivity in mallard ducklings.

Rule-governed and contingency-governed fears

Behavioral research suggests that rule-governed behavior should be less sensitive to environmental changes and thus more resistant to extinction (disconfirmation) than contingency-governed behavior. The opposite is implied in Davey's discussion of ontogenetic and phylogenetic contributions to fear development. The generality of the behavioral findings and their apparent inconsistency with the present article should be further explored with more sensitive research paradigms.

The generalized expectancy bias: An explanatory enigma

According to Davey, generalized expectancy biases cause fearrelevant behavior and may complement Seligman's biological preparedness model. Expectancy biases do not explain the preparedness phenomenon, because such cognitive (or covert behavioral) processes are themselves controlled by social and other environmentally based contingencies. Davey's own examination of the importance of cross-cultural factors can show the relationship between FR stimuli and behavior without needing cognitive agency to explain the behavioral phenomenon.

Brief cognitive-behavioral versus nondirective therapy for panic disorder

Thirty panic disorder patients were assigned randomly to four weekly sessions of either cognitive-behavioral therapy or nondirective, supportive therapy. Dependent variables included clinician ratings, standardized self-report questionnaires, and self-monitoring. Cognitive-behavioral therapy led to significant reductions in worry about the recurrence of panic, and in overall ratings of phobic distress. Nondirective supportive therapy did not produce significant effects. In addition, proportionately more patients who were actively panicking at preassessment and underwent cognitive-behavioral treatment were free of panic after treatment. More than one third (38%) of patients who received cognitive-behavioral treatment were sufficiently improved that they withdrew from the pharmacological trial and/or did not meet criteria for panic disorder by the end of the four weeks.

Enhanced processing of threatening stimuli: The case of face recognition

Because of their evolutionary importance, threat-detection mechanisms are likely to exist at a variety of levels. A recent study of face recognition suggests that novel stimuli receive enhanced processing when presented as fear-related. This suggests the existence of a complex, context-dependent threat-detection mechanism that can adaptively respond to spatiotemporally varying and unique environmental features.

Why are phobias irrational?

We endorse Davey's view that expectancy processes are intimately involved in fear reactions, but question his model on three grounds. First, the mechanism for generating expectancy bias to both ontogenetic and phylogenetic stimuli is not spelled out. Second, the selective association component is unnecessary. Third, the model fails to provide a clear explanation for the irrationality of phobic reactions.

Biologically primed acquisition of aversions and association of expected stimulus pairs: Two different forms of learning

The present commentary emphasizes that the acquisition of fear always involves complex changes in several quasi-independent response systems. Stimulus-specific electrodermal response differentiation as well as the bias to overestimate the belongingness of certain stimulus pairs mainly indicates cognitive processes of selective orienting and attention. Emotion, however, also involves the activation of subcortical motivational circuits. Why certain stimuli acquire rapid access to these basic motivational systems is not explained by the expectancy bias model.

Associative learning: Stimulus arrangement and response consistency

Studies on associative learning in normals and patients need appropriate dependent measures which are sensitive enough to reflect stimulus-specific responses and also consider the context in which the conditioning takes place. Patient's fear responses, once acquired, seem to be maintained by specific cognitive biases such as individual belief systems and a tendency to stay consistent with their previous judgments.

What is the critical evidence favoring expectancy bias theory, and where is it?

Davey has failed to clarify the critical evidence that could corroborate the expectancy bias hypothesis and refute preparedness theory. Such a clarification is necessary because each theory could potentially allow for multiple distal and proximal influences on selective associations. Expectancies are not the only proximal mediators. Our recent findings indicate that affective response matching may be an additional factor promoting such associations.