Anosognosia: the neurology of beliefs and uncertainties.

Anosognosia is a common, fascinating, and ill-understood disorder following brain damage, where patients who suffer severe deficits such as hemiplegia may remain unaware of and deny their handicap. Many studies including recent work published in this journal have attempted to determine the neurological, cognitive, and motivational bases of anosognosia. These studies have typically focused on descriptive correlations between anosognosia and various clinical factors, but did not identify a consistent pattern of brain lesion or dysfunction. Rather, the results have emphasized the complex and multifacet nature of anosognosia. This review discusses the implications of existing results, and proposes a general " framework for anosognosia where various problems in Appreciation, Belief, and Check operations may contribute to abnormal cognitive and affective appraisal of a deficit. New experimental approaches and new therapeutic tools are needed to better understand the neurocognitive mechanisms responsible for our awareness of normal functioning and failures.