•Review demonstrating the role of fear acquisition, generalization, extinction, return, and avoidance learning for anxiety disorders.•Basic research needs to target distinct mechanism such as ...extinction (generalization) and avoidance.•Basic research needs to target individual differences pertinent to anxiety disorders such as comorbid depression, age, and sex.•Basic research needs to target paradigms involving ambiguity and conflict.•Clinical translation studies are needed to validate basic research strategies aiming at treatment optimization.
Anxiety disorders are the most common mental disorders and are often chronic and disabling. Although exposure-based treatments are effective, a substantial number of individuals fail to fully remit or experience a return of symptoms after treatment. Understanding the critical processes underlying the development and treatment of anxiety disorders will help identify individuals at risk and optimize treatments. Aversive associative learning offers explanatory pathways through which fear and anxiety emerge, spread, persist, and resurge. This narrative review examines the advances made in our understanding of associative fear and avoidance learning in anxiety disorders. Overall, the extant literature supports a key role of aversive associative learning in the development and treatment of anxiety disorders. However, research targeting specific mechanisms such as extinction generalization and avoidance, the fragility of extinction, and moderating influences of individual differences pertinent to anxiety disorders (e.g., age, sex, depression) is needed. We discuss the need for more ecological valid and complex paradigms to model ambiguity and conflict as well as for clinical translation studies to optimize treatment.
Conflicts between avoiding feared stimuli versus approaching them for competing rewards are essential for functional behavior and anxious psychopathology. Yet, little is known about the underlying ...decision process. We examined approach-avoidance decisions and their temporal dynamics when avoiding Pavlovian fear stimuli conflicted with gaining rewards. First, a formerly neutral stimulus (CS+) was repeatedly paired with an aversive stimulus (US) to establish Pavlovian fear. Another stimulus (CS-) was never paired with the US. A control group received neutral tones instead of aversive USs. Next, in each of 324 trials, participants chose between a CS-/low reward and a CS+/high reward option. For the latter, probability of CS+ presentation (Pavlovian fear information) and reward magnitude (reward information) varied. Computer mouse movements were tracked to capture the decision dynamics. Although no more USs occurred, pronounced and persistent costly avoidance of the Pavlovian fear CS+ was found. Time-continuous multiple regression of movement trajectories revealed a stronger and faster impact of Pavlovian fear compared to reward information during decision-making. The impact of fear information, but not reward information, modestly decreased across trials. These findings suggest a persistently stronger weighting of fear compared to reward information during approach-avoidance decisions, which may facilitate the development of pathological avoidance.
•Originates from discussions on replicability and researcher’s degrees of freedom.•Aims at stimulating discussions on methods applied in fear conditioning research.•Addresses critical issues on ...terminology, design, methods, analysis.•Serves as comprehensive compendium and critical evaluation of read-out measures.•Highlights methodological considerations when studying individual differences.
The so-called ‘replicability crisis’ has sparked methodological discussions in many areas of science in general, and in psychology in particular. This has led to recent endeavours to promote the transparency, rigour, and ultimately, replicability of research. Originating from this zeitgeist, the challenge to discuss critical issues on terminology, design, methods, and analysis considerations in fear conditioning research is taken up by this work, which involved representatives from fourteen of the major human fear conditioning laboratories in Europe.
This compendium is intended to provide a basis for the development of a common procedural and terminology framework for the field of human fear conditioning. Whenever possible, we give general recommendations. When this is not feasible, we provide evidence-based guidance for methodological decisions on study design, outcome measures, and analyses. Importantly, this work is also intended to raise awareness and initiate discussions on crucial questions with respect to data collection, processing, statistical analyses, the impact of subtle procedural changes, and data reporting specifically tailored to the research on fear conditioning.
Maladaptive safety behavior maintains fear and anxiety by prohibiting inhibitory learning about the non-occurrence of feared outcomes (known as protection from extinction). Not engaging in safety ...behavior, however, requires to act opposite to fear-motivated behavioral tendencies. The initiation of such fear-opposite action by positive outcomes, which were in conflict with safety behavior, was tested. Following fear acquisition to a warning signal (CS+), participants acquired safety behavior to prevent the aversive outcome (n = 48). Next, safety behavior also prevented gaining rewards. In a control group (n = 50), neutral outcomes were presented to control for novelty effects of the second outcome. Subsequently, no aversive outcome occurred anymore. Phases with safety behavior were intermitted by phases without safety behavior being available to examine cognitive and physiological indicators of fear and anxiety. Without competing positive outcomes, safety behavior was frequently executed, persisted in absence of the aversive outcome, and prohibited extinction learning. Positive outcomes clearly reduced safety behavior despite equal levels of acquired fear. This enabled fear extinction as soon as the aversive outcome was absent. Importantly, this extinction learning resulted in attenuated fear and anxiety responses when safety behavior became unavailable. Post-hoc findings indicated that the mere anticipation of positive outcomes slightly reduced safety behavior. Thus, competing positive outcomes triggered fear-opposite action that prevented persistent safety behavior and protection from extinction.
•Tested incentive-based extinction of safety behavior (SB) and impact on fear and anxiety.•SB frequent, persistent, linked to protection from extinction w/o competing positive outcomes.•Positive outcomes reduced SB despite same levels of acquired fear and anxiety.•Reduced SB enabled fear extinction as soon as the aversive event was absent.•Incentive-based extinction prevented persistent SB and protection from extinction.
Purpose
Examine the effects of an 8-week yoga therapy on fatigue in patients with different types of cancer.
Methods
A total of 173 cancer patients suffering from mild to severe fatigue were randomly ...allocated to yoga intervention (
n
= 84) (IG) versus waitlist control group (CG) (
n
= 88). Yoga therapy consisted of eight weekly sessions with 60 min each. The primary outcome was self-reported fatigue symptoms. Secondary outcomes were symptoms of depression and quality of life (QoL). Data were assessed using questionnaires before (T0) and after yoga therapy for IG versus waiting period for CG (T1).
Results
A stronger reduction of general fatigue (
P
= .033), physical fatigue (
P
= .048), and depression (
P
< .001) as well as a stronger increase in QoL (
P
= .002) was found for patients who attended 7 or 8 sessions compared with controls. Within the yoga group, both higher attendance rate and lower T0-fatigue were significant predictors of lower T1-fatigue (
P
≤ .001). Exploratory results revealed that women with breast cancer report a higher reduction of fatigue than women with other types of cancer (
P
= .016) after yoga therapy.
Conclusion
The findings support the assumption that yoga therapy is useful to reduce cancer-related fatigue, especially for the physical aspects of fatigue. Women with breast cancer seem to benefit most, and higher attendance rate results in greater reduction of fatigue.
Trial registration
German Clinical Trials Register DRKS00016034
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.
Objective
To examine the efficacy of reminder e-mails to continue yoga therapy on practice frequency and fatigue in cancer patients and long-term effects of yoga on fatigue, depression, and quality ...of life.
Methodology
One hundred two cancer patients who completed an 8-week yoga therapy were randomly allocated to two groups: reminder (
N
= 51) vs. no-reminder group (
N
= 51). After completing yoga therapy, the reminder group received weekly e-mails for 24 weeks, which reminded them of practicing yoga, whereas the no-reminder group did not. Primary outcomes were fatigue and practice frequency, and long-term outcomes were fatigue, depression, and quality of life. Data were assessed using questionnaires after yoga therapy (T1) and 6 months after completing yoga therapy (T2).
Result
A significantly stronger reduction of general (
p
= 0.038,
d
= 0.42) and emotional fatigue (
p
= 0.004,
d
= 0.59) and a higher increase of practice frequency (
p
= 0.015,
d
= 0.52) between T1 and T2 were found for the reminder group compared to the no-reminder group. In the mediation model, practice frequency as a mediator partially explained the changes in emotional fatigue (indirect effect
B
= − 0.10). Long-term effects of yoga therapy regarding fatigue, depression, and quality of life were found (
F
> 7.46,
p
< 0.001,
d
> 0.54).
Conclusion
Weekly reminder e-mails after yoga therapy can positively affect general and emotional fatigue and help cancer patients with fatigue establish a regular yoga practice at home. However, higher practice frequency did not lead to higher physical or cognitive fatigue improvement, suggesting other factors that mediate efficacy on physical or cognitive fatigue, such as mindfulness or side effects of therapy.
It remains unclear if diminished high frequency heart rate variability (HF-HRV) can be found across anxiety disorders. HF-HRV and heart rate (HR) were examined in panic (PD), generalized anxiety ...(GAD), social anxiety (SAD), and obsessive–compulsive disorder (OCD) relative to healthy controls at baseline and during anxiety stressors. All disorders evidenced diminished baseline HF-HRV relative to controls. Baseline HRV differences were maintained throughout relaxation. For hyperventilation, PD and GAD demonstrated greater HR than controls. Psychotropic medication did not account for HF-HRV differences except in OCD. Age and sex evidenced multiple main effects. Findings suggest that low baseline HF-HRV represents a common index for inhibitory deficits across PD, GAD, and SAD, which is consistent with the notion of autonomic inflexibility in anxiety disorders. Elevated HR responses to hyperventilation, however, are specific to PD and GAD.
► Patients with panic, obsessive–compulsive, generalized, and social anxiety disorder. ► Heart rate (HR) and HR variability (HRV) at rest, hyperventilation, and relaxation. ► Lower HRV in all four anxiety disorders at rest compared to healthy controls. ► Lower HRV maintained, but not increased during relaxation. ► Elevated HR to hyperventilation only in panic and generalized anxiety patients.
In the interplay of fear and avoidance, not only imminent threat signals that directly predict potential threat evoke avoidance, but also distal threat signals that predict these imminent threat ...signals. Avoidance of learnt fear refers to avoidance to a distal threat signal that prevents the occurrence of an imminent threat signal. In clinical anxiety, it is often pathological given its persistence in the absence of threat and the impairments it inflicts. The current study examined whether fear extinction to an imminent threat signal would effectively reduce avoidance of learnt fear in a sensory preconditioning procedure. Three neutral preconditioning stimuli (PSs), serving as distal threat or safety signals, were paired with three neutral to-be conditioned stimuli (CSs), serving as imminent threat or safety signals. After assessing baseline levels of costly avoidance to the PSs, two CSs were paired with threat. One of these CSs then ceased to predict threat during extinction training. In test, participants showed limited avoidance to the PS that signaled the extinguished CS, however, the level of avoidance was still stronger compared to a PS that signaled a safety CS. Results suggest that exposure to an imminent threat signal partly reduces avoidance to a distal threat.
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.
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