Gemma Reynolds

Effect of vicarious fear learning on children's heart rate responses and attentional bias for novel animals

Research with children has shown that vicarious learning can result in changes to 2 of Lang’s (1968) 3 anxiety response systems: subjective report and behavioral avoidance. The current study extended this research by exploring the effect of vicarious learning on physiological responses (Lang’s final response system) and attentional bias. The study used Askew and Field’s (2007) vicarious learning procedure and demonstrated fear-related increases in children’s cognitive, behavioral, and physiological responses. Cognitive and behavioral changes were retested 1 week and 1 month later, and remained elevated. In addition, a visual search task demonstrated that fear-related vicarious learning creates an attentional bias for novel animals, which is moderated by increases in fear beliefs during learning. The findings demonstrate that vicarious learning leads to lasting changes in all 3 of Lang’s anxiety response systems and is sufficient to create attentional bias to threat in children.

Stimulus fear-relevance and the vicarious learning pathway to childhood fears

Enhanced fear learning for fear-relevant stimuli has been demonstrated in procedures with adults in the laboratory. Three experiments investigated the effect of stimulus fear-relevance on vicarious fear learning in children (aged 6-11 years). Pictures of stimuli with different levels of fear-relevance (flowers, caterpillars, snakes, worms, and Australian marsupials) were presented alone or together with scared faces. In line with previous studies, childrens fear beliefs and avoidance preferences increased for stimuli they had seen with scared faces. However, in contrast to evidence with adults, learning was mostly similar for all stimulus types irrespective of fear-relevance. The results support a proposal that stimulus preparedness is bypassed when children observationally learn threat-related information from adults.

Inhibition of vicariously learned fear in children using positive modeling and prior exposure

One of the challenges to conditioning models of fear acquisition is to explain how different individuals can experience similar learning events and only some of them subsequently develop fear. Understanding factors moderating the impact of learning events on fear acquisition is key to understanding the etiology and prevention of fear in childhood. This study investigates these moderators in the context of vicarious (observational) learning. Two experiments tested predictions that the acquisition or inhibition of fear via vicarious learning is driven by associative learning mechanisms similar to direct conditioning. In Experiment 1, 3 groups of children aged 7 to 9 years received 1 of 3 inhibitive information interventions—psychoeducation, factual information, or no information (control)—prior to taking part in a vicarious fear learning procedure. In Experiment 2, 3 groups of children aged 7 to 10 years received 1 of 3 observational learning interventions—positive modeling (immunization), observational familiarity (latent inhibition), or no prevention (control)—before vicarious fear learning. Results indicated that observationally delivered manipulations inhibited vicarious fear learning, while preventions presented via written information did not. These findings confirm that vicarious learning shares some of the characteristics of direct conditioning and can explain why not all individuals will develop fear following a vicarious learning event. They also suggest that the modality of inhibitive learning is important and should match the fear learning pathway for increased chances of inhibition. Finally, the results demonstrate that positive modeling is likely to be a particularly effective method for preventing fear-related observational learning in children.

The effect of disgust and fear modeling on children's disgust and fear for animals

Disgust is a protective emotion associated with certain types of animal fears. Given that a primary function of disgust is to protect against harm, increasing children’s disgust-related beliefs for animals may affect how threatening they think animals are and their avoidance of them. One way that children’s disgust beliefs for animals might change is via vicarious learning: by observing others responding to the animal with disgust. In Experiment 1, children (ages 7–10 years) were presented with images of novel animals together with adult faces expressing disgust. Children’s fear beliefs and avoidance preferences increased for these disgust-paired animals compared with unpaired control animals. Experiment 2 used the same procedure and compared disgust vicarious learning with vicarious learning with fear faces. Children’s fear beliefs and avoidance preferences for animals again increased as a result of disgust vicarious learning, and animals seen with disgust or fear faces were also rated more disgusting than control animals. The relationship between increased fear beliefs and avoidance preferences for animals was mediated by disgust for the animals. The experiments demonstrate that children can learn to believe that animals are disgusting and threatening after observing an adult responding with disgust toward them. The findings also suggest a bidirectional relationship between fear and disgust with fear-related vicarious learning leading to increased disgust for animals and disgust-related vicarious learning leading to increased fear and avoidance.

Reductions in Children’s Vicariously Learnt Avoidance and Heart Rate Responses Using Positive Modeling

Recent research has indicated that vicarious learning can lead to increases in children’s fear beliefs and avoidance preferences for stimuli and that these fear responses can subsequently be reversed using positive modeling (counterconditioning). The current study investigated children’s vicariously acquired avoidance behavior, physiological responses (heart rate), and attentional bias for stimuli and whether these could also be reduced via counterconditioning. Ninety-six (49 boys, 47 girls) 7- to 11-year-olds received vicarious fear learning for novel stimuli and were then randomly assigned to a counterconditioning, extinction, or control group. Fear beliefs and avoidance preferences were measured pre- and post-learning, whereas avoidance behavior, heart rate, and attentional bias were all measured post-learning. Control group children showed increases in fear beliefs and avoidance preferences for animals seen in vicarious fear learning trials. In addition, significantly greater avoidance behavior, heart rate responding, and attentional bias were observed for these animals compared to a control animal. In contrast, vicariously acquired avoidance preferences of children in the counterconditioning group were significantly reduced post-positive modeling, and these children also did not show the heightened heart rate responding to fear-paired animals. Children in the extinction group demonstrated comparable responses to the control group; thus the extinction procedure showed no effect on any fear measures. The findings suggest that counterconditioning with positive modelling can be used as an effective early intervention to reduce the behavioral and physiological effects of vicarious fear learning in childhood.

Learning to fear a second-order stimulus following vicarious learning.

ABSTRACT Vicarious fear learning refers to the acquisition of fear via observation of the fearful responses of others. The present study aims to extend current knowledge by exploring whether second-order vicarious fear learning can be demonstrated in children. That is, whether vicariously learnt fear responses for one stimulus can be elicited in a second stimulus associated with that initial stimulus. Results demonstrated that childrens (5–11 years) fear responses for marsupials and caterpillars increased when they were seen with fearful faces compared to no faces. Additionally, the results indicated a second-order effect in which fear-related learning occurred for other animals seen together with the fear-paired animal, even though the animals were never observed with fearful faces themselves. Overall, the findings indicate that for children in this age group vicariously learnt fear-related responses for one stimulus can subsequently be observed for a second stimulus without it being experienced in a fear-related vicarious learning event. These findings may help to explain why some individuals do not recall involvement of a traumatic learning episode in the development of their fear of a specific stimulus.

Lack of evidence for inhibitory processes in over-selectivity

Stimulus over-selectivity can be defined as control over behavior being exerted by one aspect of the environment at the expense of other equally salient aspects of the environment, and is a common problem for discrimination learning under conditions of cognitive strain, and in intellectual disorders. Non-clinical participants exposed to a concurrent task load were trained and tested on a two-component trial-and-error discrimination task to investigate whether inhibition plays a role in producing under-selectivity by using both summation and retardation tests. Experiment 1 found evidence for the over-selectivity effect, and replicated the finding that revaluation of a previously over-selected stimulus allows emergence of control by a previous under-selected stimulus, despite the latter stimulus receiving no direct conditioning. The under-selected cue was not found to gain any conditioned inhibitory status, as reflected by summation (Experiment 2), and retardation (Experiment 3), tests. The results extend the literature explaining over-selectivity as a post-acquisition failure.

Effects of Schedule of Reinforcement on Over-Selectivity.

Stimulus over-selectivity refers to behavior being controlled by one element of the environment at the expense of other equally salient aspects of the environment. Four experiments trained and tested non-clinical participants on a two-component trial-and-error discrimination task to explore the effects of different training regimes on over-selectivity. Experiments 1 and 2 revealed no differentiation between partial reinforcement (PR) and continuous reinforcement (CRF) on over-selectivity. Experiments 3 and 4 both found that a change in reinforcement (from CRF to PR in Experiment 3, and from PR to CRF in Experiment 4) did not reduce levels of over-selectivity, but rather continuing training with the same contingency (either CRF or PR) did reduce over-selectivity. The results support assumptions made by the comparator hypothesis, extending the growing body of literature explaining over-selectivity as a post-acquisition, rather than attention, failure.

Predictors of treatment outcome in depression in later life: A systematic review and meta-analysis

BACKGROUND Predictor analyses of late-life depression can be used to identify variables associated with outcomes of treatments, and hence ways of tailoring specific treatments to patients. The aim of this review was to systematically identify, review and meta-analyse predictors of outcomes of any type of treatment for late-life depression. METHODS Pubmed, Embase, CINAHL, Web of Science and PsycINFO were searched for studies published up to December 2016. Primary and secondary studies reported treatment predictors from randomised controlled trials of any treatment for patients with major depressive disorder aged over 60 were included. Treatment outcomes included response, remission and change in depression score. RESULTS Sixty-seven studies met the inclusion criteria. Of 65 identified statistically significant predictors, only 7 were reported in at least 3 studies. Of these, 5 were included in meta-analyses, and only 3 were statistically significant. Most studies were rated as being of moderate to strong quality and satisfied key quality criteria for predictor analyses. LIMITATIONS The searches were limited to randomised controlled trials and most of the included studies were secondary analyses. CONCLUSIONS Baseline depression severity, co-morbid anxiety, executive dysfunction, current episode duration, early improvement, physical illnesses and age were reported as statistically significant predictors of treatment outcomes. Only the first three were significant in meta-analyses. Subgroup analyses showed differences in predictor effect between biological and psychosocial treatment. However, high heterogeneity and small study numbers suggest a cautious interpretation of results. These predictors were associated with various mechanisms including brain pathophysiology, perceived social support and proposed distinct types of depressive disorder. Further investigation of the clinical utility of these predictors is suggested.

TNF alpha inhibitors in Alzheimer’s disease: a systematic review

The objective of this study was to evaluate the effect of tumour necrosis factor‐alpha inhibitors (TNF‐αI) on Alzheimers disease‐associated pathology.