A Novel Sensory Pre-Conditioning Paradigm to Assess Inferential Fear Generalization

Abstract

Fear generalization is a survival mechanism that helps us predict threat and adjust our responses to potentially dangerous stimuli. Thus, through fear generalization, the fear response can transfer from the original threat predictor to other stimuli. Even though adaptive, over-generalization of fear is the hallmark of anxiety disorders; thus, studying its underlying processes is essential for both preventing and treating anxiety-related disorders. Prior research shows that fear generalization may also occur in cases where there is no direct pairing between the threat predictor and the threat itself. A high-order inference is required for this kind of generalization. A possible underlying mechanism in the human brain for this inference process is “spontaneous experience replay." This process takes time, requires cognitive resources, and as a result, the replay allows the attribution of previously learned associations to new stimuli. However, inferential generalization within the context of fear has not yet been explored. To address this gap, we developed a three-phase sensory preconditioning paradigm exploring inferential fear generalization. Additionally, previous research found that childhood trauma impairs fear learning. However, its relationship with inferential fear generalization has never been explored. Thus, this study aimed to 1) establish a novel sensory pre-conditioning paradigm and investigate whether we could interfere with the revaluation necessary for inferential fear generalization by manipulating cognitive load 2) examine whether there was a correlation between childhood trauma and inferential fear generalization. The results suggest that the paradigm did not lead to fear generalization. Even though there was successful fear conditioning, there was no retention of the fear during the first trial of the test phase, which may have caused the lack of generalization. Also, there was no correlation between childhood trauma and fear generalization, which could have been due to the absence of fear generalization. In summary, our study was the first to use a sensory preconditioning paradigm with sequences to explore inferential fear generalization, allowing us to measure how much fear generalizes to stimuli inside the sequence. It was also the first study to look at how cognitive load affected this process and if inferential fear generalization was connected to childhood trauma. Thus, this study lays the groundwork on which future inferential fear generalization studies can be improved upon.