Inhibition of return in fear of spiders: Discrepant eye movement and reaction time data

Inhibition of return (IOR) refers to a bias against returning the attention to a previously attended location. As a foraging facilitator it is thought to facilitate systematic visual search. With respect to neutral stimuli, this is generally thought to be adaptive, but when threatening stimuli appear in our environment, such a bias may be maladaptive. This experiment investigated the influence of phobia-related stimuli on the IOR effect using a discrimination task. A sample of 50 students (25 high, 25 low in spider fear) completed an IOR task including schematic representations of spiders or butterflies as targets. Eye movements were recorded and to assess discrimination among targets, participants indicated with button presses if targets were spiders or butterflies. Reaction time data did not reveal a significant IOR effect but a significant interaction of group and target; spider fearful participants were faster to respond to spider targets than to butterflies. Furthermore, eye-tracking data showed a robust IOR effect independent of stimulus category. These results offer a more comprehensive assessment of the motor and oculomotor factors involved in the IOR effect

A Systematic Review of the Inter-individual Differences in Avoidance Learning

Avoidance is typically adaptive given it prevents threat. However, avoidance becomes maladaptive when it is executed out of proportion of threat (i.e., excessive or insufficient avoidance), persists in the absence of threat, or excessively generalizes to other innocuous situations. Although there has been an increase in research in these different processes of maladaptive avoidance, the role of inter-individual differences in these avoidance processes receives less research attention, despite its theoretical and clinical importance. In this systematic review, we summarized the role of inter-individual traits that relate to risk or resilient factors for anxiety-related disorders, trauma-and stressor-related disorders, obsessive-compulsive related disorders, pain related disorders, eating-related disorders, and affective disorders. A majority of the inter-individual differences had an apparent mixed or null effect on the different processes of avoidance. We discussed this lack of evidence of inter-individual differences on avoidance due to a lack of methodological and/or analytical consensus in the field, in addition to a lack of integration of recent findings into existing theories. Recommendations for future research are discussed, with a focus on examining the conditions or experimental parameters for certain inter-individual traits to manifest their effects on avoidance, identifying the nuances of methodological and/or inter-individual differences in avoidance, and a call for integrating recent preliminary findings into existing theories.</p

Reducing the return of avoidance and fear by directly targeting avoidance:Comparing incentive-based and instructed extinction of avoidance to passive fear extinction

Enhancing the reduction of avoidance may optimize treatment for anxiety disorders. Past research focused on boosting fear extinction to reduce avoidance, however, with limited success. Directly extinguishing avoidance may be more promising. This preregistered study tested the impact of incentives and instruction for non-avoidance compared to passive fear extinction on long-term avoidance and fear reduction. On Day 1, participants acquired conditioned fear and avoidance to a conditioned stimulus (CS) paired with an aversive outcome. Next, incentives or instructions encouraged non-avoidance to the CS, which was no longer reinforced by a US regardless of avoidance (Incentives and Instruction group). In a third group, avoidance was unavailable and the CS was passively presented in absence of the US (Passive Fear Extinction group). On Day 2, avoidance retention and reinstatement and return of fear were tested. In the short term, incentives and instruction strongly reduced avoidance with similar fear reduction compared to passive fear extinction. Importantly, incentives and instruction were linked to lower long-term avoidance retention. Avoidance reinstatement was evident in all groups, but avoidance remained higher after passive fear extinction. Finally, incentives yielded a lower return of threat expectancies. Thus, targeting avoidance instead of fear better reduced long-term avoidance and, for incentives, the return of fear. Especially, incentives could be a promising add-on to exposure.</p

Threat belief determines the degree of costly safety behavior:Assessing rule-based generalization of safety behavior with a dimensional measure of avoidance

Excessive generalization of safety behavior to innocuous stimuli that resemble a feared stimulus is oftentimes pathological especially with inflicted impairments. Safety behavior is conventionally assessed dichotomously, requiring multiple presentations of each test stimulus for assessing the proportion of safety behavior executed. Thus, the generalization gradient confounds with ongoing extinction learning during non-reinforced test trials. The present study employed a recently developed dimensional measure of avoidance to examine the extent of safety behavior generalization. We found that a dimensional measure of avoidance was able to assess the generalization gradients of safety behavior even when each test stimulus was presented once, thus minimizing the effect of ongoing extinction learning. Of equal importance is whether higher-order cognitive processes shape generalization of safety behavior. We found a range of distinct generalization gradients in safety behavior, which were highly consistent with participants’ verbally reported relational rules. This rule-based generalization parallels to how clinically anxious individuals develop different threat beliefs after trauma exposure, and models how these distinct threat beliefs determine the extent of safety behavior engagement.</p

Reduction of costly safety behaviors after extinction with a generalization stimulus is determined by individual differences in generalization rules

Exposure-based treatment involves repeated presentation of feared stimuli or situations in the absence of perceived threat (i.e., extinction learning). However, the stimulus or situation of fear acquisition (CS+) is highly unlikely to be replicated and presented during treatment. Thereby, stimuli that resemble the CS+ (generalization stimuli; GSs) are typically presented. Preliminary evidence suggests that depending on how one generalizes fear (i.e., different generalization rules), presenting the same GS in extinction leads to differential effectiveness of extinction learning. The current study aimed to extend this finding to safety behaviors. After differential fear and avoidance conditioning, participants exhibited discrete generalization gradients that were consistent with their reported generalization rules (Similarity vs Linear). The Linear group showed stronger safety behaviors to a selected GS compared to the Similarity group, presumably due to higher threat expectancy. After extinction learning to this GS, the Linear group exhibited stronger reduction in safety behaviors generalization compared to the Similarity group. The results show that identifying distinct generalization rules allows one to predict expectancy violation to the extinction stimulus, in addition to corroborating the idea that strongly violating threat expectancy leads to better extinction learning and its generalization. With regard to clinical implications, identifying one's generalization rule (e.g., threat beliefs) help designing exposure sessions that evoke strong expectancy violation, enhancing the reduction in the generalization of maladaptive safety behaviors.</p

A dimensional measure of safety behavior: A non-dichotomous assessment of costly avoidance in human fear conditioning

Safety behavior prevents the occurrence of threat, thus it is typically considered adaptive. However, safety behavior in anxiety-related disorders is often costly, and persists even the situation does not entail realistic threat. Individuals can engage in safety behavior to varying extents, however, these behaviors are typically measured dichotomously (i.e., to execute or not). To better understand the nuances of safety behavior, this study developed a dimensional measure of safety behavior that had a negative linear relationship with the admission of an aversive outcome. In two experiments, a Reward group receiving fixed or individually calibrated incentives competing with safety behavior showed reduced safety behavior than a Control group receiving no incentives. This allowed extinction learning to a previously learnt warning signal in the Reward group (i.e., updating the belief that this stimulus no longer signals threat). Despite the Reward group exhibited extinction learning, both groups showed a similar increase in fear to the warning signal once safety behavior was no longer available. This null group difference was due to some participants in the Reward group not incentivized enough to disengage from safety behavior. Dimensional assessment revealed a dissociation between low fear but substantial safety behavior to a safety signal in the Control group. This suggests that low-cost safety behavior does not accurately reflect the fear-driven processes, but also other non-fear-driven processes, such as cost (i.e., engage in safety behavior merely because it bears little to no cost). Pinpointing both processes is important for furthering the understanding of safety behavior

Data from the paper: From avoidance to approach: The influence of threat-of-shock on reward-based decision making

Potential threat can prime defensive responding and avoidance behavior, which may result in the loss of rewards. When aversive consequences do not occur, avoidance should, thus, be quickly overcome in healthy individuals. This study examined the impact of threat anticipation on reward-based decisions. Sixty-five participants completed a decision-making task in which they had to choose between high- and low-reward options. To model an approach-avoidance conflict, the high-reward option was contingent with a threat-of-shock cue; the low-reward option was contingent with a safety cue. In control trials, decisions were made without threat/safety instructions. Overall, behavioral data documented a typical preference for the profitable option. Importantly, under threat-of-shock, participants initially avoided the profitable option (i.e., safe, but less profitable choices). However, when they experienced that shocks did actually not occur, participants overcame initial avoidance in favor of larger gains. Furthermore, autonomic arousal (skin conductance and heart rate responses) was elevated during threat cues compared to safety and non-threatening control cues. Taken together, threat-of-shock was associated with behavioral consequences: initially, participants avoided threat-related options but made more profitable decisions as they experienced no aversive consequences. Although socially acquired threat contingencies are typically stable, incentives for approach can help to overcome threat-related avoidance

Avoidance and its bi-directional relationship with conditioned fear:Mechanisms, moderators, and clinical implications

Fear motivates different types of defensive behaviors. These behaviors are, however, not mere byproducts of fear. In this review, we highlight a bi-directional relationship between conditioned fear and instrumental defensive behavior in humans. We discuss mechanisms involved in the link from fear to goal-directed avoidance (e.g., relief, generalization), that may become habitual. These defensive behaviors may in turn reduce, preserve, or amplify fear responding (e.g., protection-from-extinction, behavior-as-information). Multiple factors moderate the bi-directional relationship. Evidence for amplifying and dampening effects of inter-individual differences (e.g., trait anxiety, distress tolerance), intra-individual states (e.g., stress), and external factors (e.g., incentives for competing behavior) on goal-directed and/or habitual defensive behavior is reviewed. However, the exact mechanisms by which these factors moderate the bi-directional relationship are still largely unknown (e.g., modulating avoidance directly vs. indirectly via conditioned fear). Finally, we discuss major implications: First, understanding factors moderating the bi-directional relationship provides insights into risk and resilience factors for anxious psychopathology. Second, specific experimental models and clinical interventions can be mapped onto distinct defensive behaviors (e.g., goal-directed vs. habitual avoidance). More precise matching will help to develop nuanced models and interventions to reduce pathological behaviors and individualize treatments.</p