The aim of the study was to generate design criteria in order to encourage and facilitate wayfinding for advanced Alzheimer’s patients. Two sources of data were used: interviews with the staff of a typical urban nursing home, and a wayfinding experience with its residents. The results show that even patients with severe cognitive deterioration are able to reach certain destinations. Wayfinding decisions have to be based on environmental information that is readily accessible, so that the patient can proceed from decision point to decision point. Monotony of architectural composition and the lack of reference points render wayfinding difficult. The elevators are seen to be a major anxiety-causing barrier. Visual access to the main destinations increases their use and facilitates wayfinding. Signage has an important function, creating redundancy in wayfinding communication and compensating for the loss of memory and spatial understanding. Floor patterns and dark lines or surfaces can disorient the patients and cause anxiety.

In the absence of visual input, the question arises as to how complex spatial abilities develop and how the brain adapts to the absence of this modality. We explored navigational skills in both early and late blind individuals and structural differences in the hippocampus, a brain region well known to be involved in spatial processing. Thirty-eight participants were divided into three groups: early blind individuals (n = 12; loss of vision before 5 years of age; mean age 33.8 years), late blind individuals (n = 7; loss of vision after 14 years of age; mean age 39.9 years) and 19 sighted, blindfolded matched controls. Subjects undertook route learning and pointing tasks in a maze and a spatial layout task. Anatomical data was collected by MRI. Remarkably, we not only show that blind individuals possess superior navigational skills than controls on the route learning task, but we also show for the first time a significant volume increase of the hippocampus in blind individuals [F(1,36) = 6.314; P < or = 0.01; blind: mean = 4237.00 mm(3), SE = 107.53; sighted: mean = 3905.74 mm(3), SE = 76.27], irrespective of whether their blindness was congenital or acquired. Overall, our results shed new light not only on the construction of spatial concepts and the non-necessity of vision for its proper development, but also on the hippocampal plasticity observed in adult blind individuals who have to navigate in this space.