A full DAPT assessment of this would again require a much larger sample, in future work. Here we found no significant (or approaching significant) correlations with the prism impact on the chimeric/non-chimeric face discrimination task, for any of these clinical factors. Nevertheless, with future research in mind, it may be worth noting that all patients who showed a prism-induced improvement in the present task were within one and five months

post onset, while patients who did not show an improvement typically had an earlier stroke (see Table 1). Moreover, those patients who did not show any significant improvement all had hemianopia, whereas only one out of the three patients who did show a significant

improvement had hemianopia. For present purposes our focus was not so much on identifying which patients may benefit from prism adaptation, as on the nature of the tasks which may or may not benefit. The most important outcome from the chimeric/non-chimeric face discrimination task is simply to show that prism adaptation can improve awareness for the left side of face stimuli in at least some CAL101 cases. Although we found this positive effect reliably only in three out of six of the patients tested here (those who tended to have smaller lesions, and be within five months of stroke onset), the unequivocal improvement in EY, AM and MK’s performance provides an existence proof that prism adaptation can in principle improve awareness for the left side even of face stimuli, at least in tasks that require explicit detection of differences (in this case emotional expression differences) between the left and the right side of a face stimulus. Our previous work (Sarri et al.,

2006) had reported that while prism therapy may apparently have no effect on neglect Astemizole patients’ awareness for the contralesional side of chimeric face tasks, when measured by forced-choice spatial preference judgements of emotional expression (in which neglect patients pathologically favour the right side of chimeric face tasks, see also Ferber et al., 2003), it can nevertheless significantly increase awareness for the left side of chimeric non-face objects. In the present study we explored potential reasons for the apparent failure of prism adaptation to alter the systematic rightward bias demonstrated by neglect patients in the chimeric face lateral preference task, despite the beneficial effect it has been shown to exert on many other aspects of neglect to date (e.g., see Rossetti et al., 1998, Rossetti et al., 2004, Rode et al., 2001, Tilikete et al., 2001, Farne et al., 2002, McIntosh et al., 2002, Maravita et al., 2003, Angeli et al., 2004, Berberovic et al., 2004, Dijkerman et al., 2004 and Pisella et al., 2006; Sarri et al., 2006, Sarri et al., 2008, Serino et al., 2007, Serino et al.