Yannick Boddez

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.

Expectancy bias in a selective conditioning procedure: trait anxiety increases the threat value of a blocked stimulus

BACKGROUND AND OBJECTIVES In a blocking procedure, a single conditioned stimulus (CS) is paired with an unconditioned stimulus (US), such as electric shock, in the first stage. During the subsequent stage, the CS is presented together with a second CS and this compound is followed by the same US. Fear conditioning studies in non-human animals have demonstrated that fear responding to the added second CS typically remains low, despite its being paired with the US. Accordingly, the blocking procedure is well suited as a laboratory model for studying (deficits in) selective threat appraisal. The present study tested the relation between trait anxiety and blocking in human aversive conditioning. METHODS Healthy participants filled in a trait anxiety questionnaire and underwent blocking treatment in the human aversive conditioning paradigm. Threat appraisal was measured through shock expectancy ratings and skin conductance. RESULTS As hypothesized, trait anxiety was positively associated with shock expectancy ratings to the blocked stimulus. LIMITATIONS In skin conductance responding, no significant effects of stimulus type could be detected during blocking training or testing. The current study does not allow strong claims to be made regarding the theoretical process underlying the expectancy bias we observed. CONCLUSIONS The observed shock expectancy bias might be one of the mechanisms leading to non-specific fear in individuals at risk for developing anxiety disorders. A deficit in blocking, or a deficit in selective threat appraisal at the more general level, indeed results in fear becoming non-specific and disconnected from the most likely causes or predictors of danger.

The validity of laboratory-based treatment research: Bridging the gap between fear extinction and exposure treatment

A major objective of experimental psychopathology research is to improve clinical practice via the experimental study of treatment mechanisms. The success of this endeavor depends on the external validity of the procedures used to model the treatment component in the laboratory. We propose a general framework and a set of specific criteria that will allow evaluating whether a certain laboratory procedure is a valid model for a certain clinical treatment. We illustrate this framework by evaluating the validity of extinction as a laboratory model for clinical exposure therapy. Although we acknowledge the merits of the extinction model, we argue that its validity might not be as firmly established as the research community assumes. We also use extinction as an example to demonstrate how considerations of the proposed criteria can stimulate further improvements to existing models of treatment. We conclude that the systematic assessment of external validity of treatment models is an important step towards bridging the gap between science and practice in the field of experimental psychopathology.

Aversive learning and generalization predict subclinical levels of anxiety: a six-month longitudinal study

The identification of premorbid markers of risk for psychopathology is one of the most important challenges for present-day psychiatric research. This study focuses on behavioral vulnerability factors that contribute to the development of anxiety. Little is known about the role of aversive learning and generalization in the development of pathological anxiety. In this study, a large student sample (N=375) completed a differential aversive learning task followed by a test of generalization. Anxiety was assessed at that moment and after a six-month follow-up. Results showed that both predictors (discrimination learning and generalization) added significantly to the explained variance in anxiety symptomatology at follow-up. These results highlight the importance of longitudinal designs and indicate that screening for individual differences in aversive learning and generalization may foster prediction of anxiety disorders, paving the way for targeted prevention.

Avoidance behavior in chronic pain research: A cold case revisited

In chronic musculoskeletal pain, avoidance behavior is a prominent behavioral characteristic that can manifest itself in various ways. It is also considered a crucial component in the development and maintenance of chronic pain-related disability, supposedly fueled by pain-related fear and catastrophic beliefs. Despite the frequent occurrence of avoidance behavior and its potential impact on quality of life, relatively little research has been dedicated to the nature of avoidance in chronic pain and its assessment, leaving its underlying mechanisms poorly understood. In the current paper, we stipulate some of the existing parallels between chronic pain research and more basic fear and anxiety research inspired by modern learning theories. After a brief introduction, we discuss avoidance theories that are likely apt to be applied to chronic pain, including avoidance as a response that can affect fear responding, and the role of avoidant decision making and motivational context. Finally, we will outline how these theories may impact clinical treatment.

Individual differences in discriminatory fear learning under conditions of ambiguity: a vulnerability factor for anxiety disorders?

Complex fear learning procedures might be better suited than the common differential fear-conditioning paradigm for detecting individual differences related to vulnerability for anxiety disorders. Two such procedures are the blocking procedure and the protection-from-overshadowing procedure. Their comparison allows for the examination of discriminatory fear learning under conditions of ambiguity. The present study examined the role of individual differences in such discriminatory fear learning. We hypothesized that heightened trait anxiety would be related to a deficit in discriminatory fear learning. Participants gave US-expectancy ratings as an index for the threat value of individual CSs following blocking and protection-from-overshadowing training. The difference in threat value at test between the protected-from-overshadowing conditioned stimulus (CS) and the blocked CS was negatively correlated with scores on a self-report tension-stress scale that approximates facets of generalized anxiety disorder (GAD), the Depression Anxiety Stress Scale-Stress (DASS-S), but not with other individual difference variables. In addition, a behavioral test showed that only participants scoring high on the DASS-S avoided the protected-from-overshadowing CS. This observed deficit in discriminatory fear learning for participants with high levels of tension-stress might be an underlying mechanism for fear overgeneralization in diffuse anxiety disorders such as GAD.

The power of goal-directed processes in the causation of emotional and other actions

Standard dual-process models in the action domain postulate that stimulus-driven processes are responsible for suboptimal behavior because they take them to be rigid and automatic and therefore the default. We propose an alternative dual-process model in which goal-directed processes are the default instead. We then transfer the dual- process logic from the action domain to the emotion domain. This reveals that emotional behavior is often attributed to stimulus-driven processes. Our alternative model submits that goal-directed processes could be the primary determinant of emotional behavior instead. We evaluate the type of empirical evidence required for validating our model and we consider implications of our model for behavior change, encouraging strategies focused on the expectancies and values of action outcomes.

The elusive nature of the blocking effect : 15 failures to replicate

With the discovery of the blocking effect, learning theory took a huge leap forward, because blocking provided a crucial clue that surprise is what drives learning. This in turn stimulated the development of novel association-formation theories of learning. Eventually, the ability to explain blocking became nothing short of a touchstone for the validity of any theory of learning, including propositional and other nonassociative theories. The abundance of publications reporting a blocking effect and the importance attributed to it suggest that it is a robust phenomenon. Yet, in the current article we report 15 failures to observe a blocking effect despite the use of procedures that are highly similar or identical to those used in published studies. Those failures raise doubts regarding the canonical nature of the blocking effect and call for a reevaluation of the central status of blocking in theories of learning. They may also illustrate how publication bias influences our perspective toward the robustness and reliability of seemingly established effects in the psychological literature. (PsycINFO Database Record

Generalization of conditioned responding: Effects of autobiographical memory specificity

Generalization of acquired responses appears to be a crucial, yet under investigated process in emotional disorders. Generalization occurs when a conditioned response is elicited by a stimulus different from the original conditioned stimulus. The expansion of complaints, often seen in emotional disorders, is at least in part due to processes of generalization. In the present study, generalization is approached from a memory perspective. It is hypothesized that generalization of conditioned responding is associated with autobiographical memory specificity. Higher levels of generalization are predicted for people who are characterized by limited memory specificity. In a human contingency-learning procedure, participants learned the association between two pictures of female faces and a schematic drawing of a lightning bolt. Subsequently, six morphed pictures functioning as generalization stimuli (GSs) were introduced and conditioned responses to these GSs were measured. The results showed that memory specificity was significantly associated with the extent of generalization. Participants low in autobiographical memory specificity exhibited significantly stronger conditioned responses to GSs as compared to participants high in autobiographical memory specificity.

The hide-and-seek of retrospective revaluation: recovery from blocking is context dependent in human causal learning

In a typical blocking procedure, pairings of a compound consisting of 2 stimuli, A and X, with the outcome are preceded by pairings of only A with the outcome (i.e., A+ then AX+). This procedure is known to diminish responding to the target cue (X) relative to a control group that does not receive the preceding training with blocking cue A. We report 2 experiments that investigated the effect of extinguishing a blocking cue on responding to the target cue in a human causal learning paradigm (i.e., A+ and AX+ training followed by A- training). The results indicate that extinguishing a blocking cue increases conditioned responding to the target cue. Moreover, this increase appears to be context dependent, such that increased responding to the target is limited to the context in which extinction of the blocking cue took place. We discuss these findings in the light of associative and propositional learning theories.