Before revision:  This positive feedback can drive large fluctuations in the internal state of URLanism away from its mean, resulting in long runs in favorable directions but short ones otherwise.
After revision:  This positive feedback can drive large fluctuations in the internal state , complicating analytical approaches. Previous studies focused on what happens when the negative feedback dominates the dynamics. By contrast, we show here that there is a large portion of physiologically-relevant parameter space where the positive feedback can dominate, even when gradients are relatively shallow. We demonstrate how large transients emerge because of non-normal dynamics (non-orthogonal eigenvectors near a stable fixed point) inherent in the positive feedback, and further identify a fundamental nonlinearity that strongly amplifies their effect. Most importantly, this amplification is asymmetric, elongating runs in favorable directions but short ones otherwise.