Anosognosia for theory of mind deficits: A single case study and a review of the literature

Being aware of one's own ability to interact socially is crucial to everyday life. After a brain injury, patients may lose their capacity to understand others' intentions and beliefs, that is, the Theory of Mind (ToM). To date, the debate on the association between ToM and other cognitive deficits (in particular executive functions and behavioural disorders) remains open and data regarding awareness of ToM deficits are meagre. By means of an ad-hoc neuropsychological battery of tests, we report on a patient who suffers from ToM deficits and is not aware of these disorders, although aware of his other symptoms. The study is accompanied by a review of the literature (PRISMA guidelines) demonstrating that ToM deficits are independent of executive functions. Furthermore, an advanced lesion analysis including tractography was executed. The results indicate that: i) ToM deficits can be specific and independent of other cognitive symptoms; ii) unawareness may be specific for ToM impairment and not involve other disorders and iii) the medial structures of the limbic, monitoring and attentional systems may be involved in anosognosia for ToM impairment.