Motor asymmetry and estimation of body-scaled aperture width in Parkinson's disease

► Parkinsonian patients and controls judged whether they would fit through doorways. ► Controls and patients with worse left-sided symptoms were accurate. ► Patients with worse right-sided symptoms selected doorways which were too small. ► Perceived body-scaled door width correlated with right:left symptom severity ratio. ► Increased surround luminance reduced perceived doorway width in all participants.