Rapid temporal accumulation in spider fear: Evidence from hierarchical drift diffusion modelling

Abstract

Fear can distort our sense of time – making time seem slow or even stand still. Here, I used Hierarchical Drift Diffusion Modelling (HDDM; Vandekerckhove, Tuerlinckx, & Lee, 2008, 2011; Wiecki, Sofer, & Frank, 2013) to test the idea that temporal accumulation speeds up during fear. Eighteen high fearful and twenty-three low fearful participants judged the duration of both feared stimuli (spiders) and non-feared stimuli (birds) in a temporal bisection task. The drift diffusion modelling results support the main hypothesis. In high but not low fearful individuals evidence accumulated more rapidly toward a long duration decision - drift rates were higher – for spiders compared to birds. This result and further insights into how fear affects time perception would not have been possible based on analyses of choice proportion data alone. Further results were interpreted in the context of a recent two-stage model of time perception (Balci & Simen, 2014). The results highlight the usefulness of diffusion modelling to test process-based explanations of disordered cognition in emotional disorders