Correlated racing evidence accumulator models

Abstract

Many models of response time that base choices on the first evidence accumulator to win a race to threshold rely on statistical independence between accumulators to achieve mathematical tractability (e.g., Brown and Heathcote, 2008; Logan et al., 2014; Van Zandt et al., 2000). However, it is psychologically plausible that trial-to-trial fluctuations can cause both positive correlations (e.g., variability in arousal, attention or response caution that affect accumulators in the same way) and negative correlations (e.g., when evidence for each accumulator is computed relative to a criterion). We examine the effects of such correlations in a racing accumulator model that remains tractable when ..