Mapping spatial attention with reaction time in neglect patients

Abstract This chapter describes two attempts to cast light on an attentional model of neglect by trying to specify two important aspects. First, it examines whether the attentional impairment concerns exogenous stimulus-driven attention or endogenous controlled attention. Second, it fits the reaction time (RT) data to the saliency map model of neglect proposed by Anderson, which is a formal model of neglect inspired by clinical data (line bisection). The overall rationale of the approach depends on the idea that speed of RT (and detection performance) at various locations in the visual field depends on both retinal and attentional factors. The RT approach used in the study of the distribution of spatial attention across the visual field in neglect patients without hemianopia has provided evidence in broad agreement with hemispatial theories of neglect. In addition, a clear-cut hemifield difference in performance is shown. Moreover, fitting the RT data to the mathematical model of neglect proposed by Anderson has proved to be a fruitful exercise.