Visual Search in Progressive Supranuclear Palsy.

Progressive supranuclear palsy is often considered a disease of the motor system and is characterised by a profound oculomotor impairment. The oculomotor system is also known to be fundamentally important in cognitive processes such as attention and working memory, but the way in which these functions are affected by PSP is not well understood. In this chapter we outline the pathology and typical presentation of PSP, with a focus on the oculomotor impairment, briefly outline the role of the oculomotor system in spatial cognition and discuss some key studies examining spatial attention and memory in PSP. We then present new data from a study that specifically examined the effect of PSP on visual search. Our results demonstrated a profound impairment of visual search which is most severe for feature search along the vertical axis. These findings are interpreted with respect to the biased-competition theory of attention, and we discuss possible clinical applications of our results.