Error-based training and emergent awareness in anosognosia for hemiplegia

Residual forms of awareness have recently been demonstrated in subjects affected by anosognosia for hemiplegia, but their potential effects in recovery of awareness remain to date unexplored. Emergent awareness refers to a specific facet of motor unawareness in which anosognosic subjects recognise their motor deficits only when they have been requested to perform an action and they realise their errors. Four participants in the chronic phase after a stroke with anosognosia for hemiplegia were recruited. They took part in an "error-full" or "analysis of error-based" rehabilitative training programme. They were asked to attempt to execute specific actions, analyse their own strategies and errors and discuss the reasons for their failures. Pre- and post-training and follow-up assessments showed that motor unawareness improved in all four patients. These results indicate that unsuccessful action attempts with concomitant error analysis may facilitate the recovery of emergent awareness and, sometimes, of more general aspects of awareness.