Our previous research has described "express visuomotor responses" in humans and animal models. Converging evidence suggests that muscle recruitment in this interval is selectively driven by signalling along the tectoreticulospinal pathway, which provides the most rapid link between vision and action. In two recent publications, we show that such signalling is spared in both the upper limb for visually-guided reaching (Gilchrist, Kozak et al 2024), and in the lower-limb for visually-guided stepping (Billen et al. 2024). These findings demonstrate that the pathophysiology of PD selectively influences some but not all descending motor circuits, and has implications for our understanding of the motor deficits and capabilities in this disease.​