What can unilateral neglect tell us about the structure of visuospatial working memory?

Some studies have proposed that deficits in visuospatial working memory (WM) could exacerbate the neglect syndrome, as reflected in the patients’ tendency to repeatedly search through items located on the right, as if they did not realize that they had previously examined the rightward locations favoured by their lateral attentional bias (e.g., Husain et al., 2001). However, we have recently shown that the efficiency level of spatial WM, as evaluated by the Corsi Block test, might not be sufficient to explain perseveration and omission behaviors in neglect patients (Wansard et al., 2014). Moreover, it appears that, until now, research has mostly focused on spatial sequential WM, addressing the study of visuospatial WM through tasks involving the recall of serial order. We will present data suggesting that other subcomponents of visuospatial WM, such as simultaneous-spatial or visual WM (Logie, 1995), could also be involved in the neglect syndrome. We will also present evidence of a double dissociation between the two aspects of visuospatial WM (simultaneous vs sequential) in neglect patients, confirming the dual dimension of visuospatial WM (Wansard et al., 2015).