Abstract
Every day, we encounter numerous conflict situations in which we have to make approach-avoidance decisions. Avoiding certain situations often provides safety from potential threats. However, avoidance behaviour can also be costly. For example, it can lead to social isolation, mental health problems, financial difficulties, and more. In situations involving approach-avoidance conflicts, most individuals are able to overcome their fears and approach the situation to pursue larger goals. However, this is often not the case for patients with anxiety disorders. Indeed, excessive avoidance is a key symptom of anxiety disorders and plays an important role in the emergence and persistence of these disorders. Remarkably, experimental paradigms investigating avoidance behaviour do not take into account that maladaptive avoidance often occurs under acute threat and comes at the cost of potential rewards. Therefore, the central aim of this dissertation is to investigate the origins of costly fearful avoidance behaviour by examining its psychological, physiological, and neural correlates. My research reveals that individuals typically balance potential rewards and threats when making approach-avoidance decisions. However, there are individual differences in how these factors are weighed: some individuals avoid due to reward insensitivity, while others avoid due to threat hypersensitivity. The role of reward in approach-avoidance decision-making under acute threat is further supported by physiological and neural evidence. These findings open up new avenues for interventions, such as counterconditioning, which aims to enhance reward sensitivity and reduce threat sensitivity, thereby decreasing avoidance behaviour. Indeed, my research demonstrates that counterconditioning is effective in reducing costly fearful avoidance.
