Ambiguity Drives Higher-Order Pavlovian Learning

In the natural world, stimulus-outcome associations are often noisy and ambiguous. Learning to disambiguate these associations to identify which specific outcomes will occur is critical for survival. Pavlovian occasion setters are stimuli that determine whether other stimuli that are ambiguous will result in a specific outcome. Occasion setting is a well-established field, but very little investigation has been conducted on how occasion setters are disambiguated when they themselves are ambiguous. We investigated the role of higher-order Pavlovian occasion setting in humans. We also developed and tested the first computational model predicting direct associations, traditional occasion setting, and 2nd-order occasion setting. Results showed that occasion setters affected ambiguous but not unambiguous lower-order stimuli and that 2nd-order occasion setting was indeed learned. Our computational model demonstrated excellent fit with the data, advancing our theoretical understanding of learning with ambiguity. These results may ultimately improve treatment of Pavlovian-based mental health disorders (e.g., anxiety)

Brief Training to Modify the Breadth of Attention Influences the Generalisation of Fear

Background: Generalisation of fear from dangerous to safe stimuli is an important process associated with anxiety disorders. However, factors that contribute towards fear (over)-generalisation remain poorly understood. The present investigation explored how attentional breadth (global/holistic and local/analytic) influences fear generalisation and, whether people trained to attend in a global vs. local manner show more or less generalisation. Methods: Participants (N = 39) were shown stimuli which comprised of large ‘global’ letters and smaller ‘local’ letters (e.g. an F comprised of As) and they either had to identify the global or local letter. Participants were then conditioned to fear a face by pairing it with an aversive scream (75% reinforcement schedule). Perceptually similar, but safe, faces, were then shown. Self-reported fear levels and skin conductance responses were measured. Results: Compared to participants in Global group, participants in Local group demonstrated greater fear for dangerous stimulus (CS +) as well as perceptually similar safe stimuli. Conclusions: Participants trained to attend to stimuli in a local/analytical manner showed higher magnitude of fear acquisition and generalisation than participants trained to attend in a global/holistic way. Breadth of attentional focus can influence overall fear levels and fear generalisation and this can be manipulated via attentional training

Maximizar la terapia de exposición: Un enfoque basado en el aprendizaje inhibitorio

Despite the effectiveness of exposure therapy for treating anxiety disorders, a number of patients fail to benefit or experience a return of fear after treatment. Research suggests that anxious individuals show deficits in the mechanisms believed to underlie exposure therapy, such as inhibitory learning. Targeting these processes may help improve the efficacy of exposure-based procedures. The primary aim of this paper is to provide examples to clinicians of how to apply the inhibitory learning model in order to optimize exposure therapy.  Exposure optimization strategies include 1) expectancy violation, 2) deepened extinction, 3) occasional reinforced extinction, 4) removal of safety signals, 5) variability, 6) retrieval cues, 7) multiple contexts, and 8) affect labeling. Case studies illustrate methods of applying these techniques in a variety of anxiety disorders.A pesar de la efectividad de la terapia de exposición para el tratamiento de los trastornos de ansiedad, algunos pacientes no se benefician de ella o experimentan un retorno del miedo después del tratamiento. La investigación sugiere que las personas con ansiedad presentan déficits en los mecanismos supuestamente implicados en la terapia de exposición, como el aprendizaje inhibitorio. Centrarse en estos mecanismos podría mejorar la eficacia de los procedimientos basados en la exposición. El principal objetivo de este artículo es proporcionar ejemplos a los clínicos sobre cómo optimizar la terapia de exposición aplicando el modelo de aprendizaje inhibitorio. Las estrategias de optimización incluyen 1) violación de expectativas, 2) extinción intensificada, 3) refuerzo ocasional durante la extinción, 4) retirada de señales de seguridad, 5) variabilidad, 6) claves de recuperación, 7) contextos múltiples y 8) etiquetado de las emociones. Mediante estudios de caso se mostrarán formas de aplicar estas técnicas en varios trastornos de ansiedad

The Effect of Positive Affect on Extinction Learning and Return of Fear

Although exposure is an effective treatment for anxiety disorders, its efficacy is limited, and efforts are being made to enhance its overall effectiveness. This dissertation evaluates one potential method of optimizing extinction learning and exposure therapy: increasing positive affect during extinction. The effect of positive affect on learning is discussed in regards to various components of learning, including attention, encoding, rehearsal, consolidation, retrieval, and stimulus appraisal. These effects are then discussed specifically with regard to extinction learning and exposure therapy. Study 1 evaluated whether positive affect is associated with lower rates of reacquisition, or, an increase in fear following re-pairings of the conditional stimulus (CS+) and unconditional stimulus (US; e.g., electric shock) after extinction. Results showed that higher positive affect before and after extinction was associated with less CS+ fear during reacquisition as measured by skin conductance arousal and US expectancy. Study 2 used a mood induction to assess its effects on spontaneous recovery, long-term extinction learning, and reacquisition. This study found null results of mood induction on fear. Study 3 evaluated the effects of mood induction on generalization of extinction learning. The results showed that positive mood induction before extinction resulted in less self-report fear of a novel generalization stimulus at test. The results of all three studies are discussed with relevance to exposure therapy

The Effect of Positive Affect on Extinction Learning and Return of Fear

Although exposure is an effective treatment for anxiety disorders, its efficacy is limited, and efforts are being made to enhance its overall effectiveness. This dissertation evaluates one potential method of optimizing extinction learning and exposure therapy: increasing positive affect during extinction. The effect of positive affect on learning is discussed in regards to various components of learning, including attention, encoding, rehearsal, consolidation, retrieval, and stimulus appraisal. These effects are then discussed specifically with regard to extinction learning and exposure therapy. Study 1 evaluated whether positive affect is associated with lower rates of reacquisition, or, an increase in fear following re-pairings of the conditional stimulus (CS+) and unconditional stimulus (US; e.g., electric shock) after extinction. Results showed that higher positive affect before and after extinction was associated with less CS+ fear during reacquisition as measured by skin conductance arousal and US expectancy. Study 2 used a mood induction to assess its effects on spontaneous recovery, long-term extinction learning, and reacquisition. This study found null results of mood induction on fear. Study 3 evaluated the effects of mood induction on generalization of extinction learning. The results showed that positive mood induction before extinction resulted in less self-report fear of a novel generalization stimulus at test. The results of all three studies are discussed with relevance to exposure therapy

Starting Fear Is a Stronger Predictor of Long-Term Fear than Rate of Change in Fear in Human Fear Conditioning

In rodent studies, faster extinction rate has been shown to predict less long-term fear. However, this has scarcely been studied in humans. The present report investigated the association between extinction rate and long-term fear in humans. We secondarily evaluated specificity of extinction rate by including other fear conditioning values as predictors, including acquisition intercept, acquisition rate, and extinction intercept. Results show that slower extinction rate predicted less long-term fear when tested alone in the model. However, when including other fear conditioning variables, extinction rate no longer predicted long-term fear. Instead, greater fear at the beginning of acquisition was the most robust predictor of greater long-term fear (all three measures of fear), followed by greater fear at the beginning of extinction (US expectancy only). These effects occurred for both the danger signal (i.e., CS+) and safety signal (i.e., CS-). The results de-emphasize rate of change in fear during both acquisition and extinction as predictors of long-term fear and instead suggest that the magnitude of fear at the start of acquisition and, secondarily, extinction are more important predictors of long-term fear. This report has relevance for improving our understanding and treatment of anxiety disorders