“…In order to separate the contributions of sensory encoding of visual motion from non-sensory aspects of the decision-making process, we revisit a widely used measure of visual motion sensitivity (random dot motion discrimination) with a mathematical modeling approach. The drift diffusion model (DDM) estimates the generating function that corresponds to an individual's pattern of responses and reaction times on a task (Ratcliff & McKoon, 2008), and has been previously used to understand how cognitive mechanisms associated with aging (Ratcliff, Thapar, & McKoon, 2004), ADHD (Huang-Pollock et al, 2017), and development (Ratcliff, Love, Thompson, & Opfer, 2012) manifest in psychophysical task performance. The model has been extensively used to describe decision-making on the motion discrimination task (Gold & Shadlen, 2007;Palmer, Huk, & Shadlen, 2005;Shadlen, Hanks, Churchland, Kiani, & Yang, 2013), and many of its assumptions are validated by electrophysiological work in non-human primates (Shadlen & Newsome, 2001).…”