Shedding new light on representational neglect: The importance of dissociating visual and spatial components

Over the last decade, many studies have demonstrated that visuospatial working memory (VSWM) can be divided into two subsystems, dealing respectively with spatial and visual information. A similar dissociation has been observed in brain-damaged patients without neglect for mental imagery skills. The first aim of the present study was to examine whether performance dissociations between spatial and visual mental imagery can be observed in unilateral neglect. The second objective was to further investigate the role of spatial and visual working memory subsystems in the mental representation abilities of neglect patients and healthy controls, and their dependence on the nature of the mental imagery tasks performed. The results showed that spatial and visual imagery processes can be selectively impaired in unilateral neglect. Spatial working memory skills were also found to strongly predict spatial imagery score in the two experimental groups. However, contrary to what was observed in healthy controls, visual working memory did not appear to predict performance on visual imagery tasks in neglect patients. Overall, these findings highlight the importance of investigating both visual and spatial components of working memory and mental imagery in neglect patients.