Avoidance behaviour: An investigation of overgeneralisation and ambiguity using trace procedures.

焦虑症是最常见的精神疾病，仅在欧洲就影响到6 000多万人，随着大流行病的持续，这些数字还在增加。所有焦虑症的一个标志是回避行为，根据DSM-V，这是焦虑的诊断标准。然而，在焦虑症方面受到关注的一个现象是过度概括。过度概括尤其发生在那些对潜在威胁模棱两可的焦虑症患者身上。当存在时间间隙（即，预测因子和危险结果之间的关系。目前还没有对人类跟踪程序的泛化进行评估，因此强调将跟踪程序与回避行为中过度泛化的评估相结合可能具有很高的研究兴趣。该项目旨在研究人类回避性能的泛化，使用一种新的跟踪程序方法。这个项目将使用一个预先存在的回避任务，在这个任务中，参与者学习区分不同的预测刺激（蓝色和绿色）和令人厌恶的结果（噪音）。在成功辨别之后，将向参与者展示蓝绿色维度的所有中间值，并进行概括测试。在不同的群体中，刺激-结果轨迹将被操纵以操纵模糊性。预期刺激-结果时间关系之间的更多模糊性将导致过度概括，从而导致更多的回避，这将由参与者的焦虑介导。如果观察到过度概括，则将研究心理机制。一种可能性是，由于时间间隔，参与者不记得预测的所有细节，导致过度概括，这种现象被称为遗忘的刺激属性。知觉辨别在概括中起着很大的作用，辨别力差会导致更广泛的概括梯度。为了评估这种回避反应，将测量参与者，并要求他们识别先前由厌恶结果跟随的刺激。这将有助于理解刺激属性是如何被回忆起来的，以及哪些元素是最好的识别。最后，将进行计算建模，以确定不同的参数，影响过度概括的避免。了解刺激泛化的基本机制，并将其纳入现有的模型将允许评估导致过度泛化的个体差异。总之，研究避免过度概括可以进一步了解潜在的机制，这反过来又可能导致治疗适应于减轻治疗后的复发。最终，这可能会导致更成功的治疗这种高度流行的疾病。

Anxiety is the most common psychiatric disorder affecting over 60 million people in Europe alone, and these numbers have increased with the ongoing pandemic. A hallmark of all anxiety disorders is avoidance behaviour, which is a diagnostic criterion for anxiety according to the DSM-V. Avoidance behaviour has been overlooked in the literature. However, a phenomenon that has received attention in relation to anxiety disorders is overgeneralisation. Overgeneralization particularly occurs in those with anxiety when there is ambiguity about potential threats. This ambiguity can occur when there is a temporal gap (i.e., trace) between predictors and dangerous outcomes. There are no assessments of generalisation with trace procedures in humans therefore highlighting that combining trace procedures with an assessment of overgeneralisation in avoidance behaviour may be of high research interest. This project aims to investigate generalisation of avoidance performance in humans, using a novel trace procedure approach. This project will use a pre-existing avoidance task in which participants learn to discriminate between different predictive stimuli (blue and green) of an aversive outcome (loud noise). Following successful discrimination, participants will be presented with all intermediate values of the blue-green dimension and tested for generalisation. In different groups the stimulus-outcome trace will be manipulated in order to manipulate the ambiguity. It is expected that more ambiguity between the stimulus-outcome temporal relationship will lead to overgeneralisation, resulting in more avoidance and this will be mediated by participant's anxiety. If overgeneralisation is observed then the psychological mechanisms will be investigated. One possibility is that due to the temporal gap participants do not remember all the details of the predictor resulting in overgeneralisation this phenomenon is known as forgetting of stimulus attributes. Perceptual discrimination plays a large part in generalisation and poor discrimination can lead to broader generalisation gradient. To assess this avoidance response will be measured and participants will be asked to identify the stimulus that was previously followed by the aversive outcome. This will lead to the understanding of how stimulus attributes are recalled and which elements are best identified. Finally computational modelling will be conducted to identify the different parameters that affect overgeneralisation of avoidance. Understanding the underlying mechanisms for stimulus generalisation and incorporating them into existing models will allow an assessment of the individual differences that lead to overgeneralisation. In summary investigating overgeneralisation in avoidance could further our understanding of the underlying mechanisms which could in turn lead to treatments being adapted to attenuate relapse following treatment. Ultimately, this could result in more successful treatments for this highly prevalent disorder.