Introduction. Beliefs have recently been defined as the neural product of perception of objects and events in the external world and of an affirmative internal affective state reflecting personal meaning. It is, however, undetermined in which way diseases of the brain affect these integrative processes.Methods. Here, the formation and updating of abnormal beliefs in cerebral disorders are described.Results. It will be shown that well-defined neuropsychological syndromes resulting from brain lesions also interfere with the neural processes that enable the formation, updating and communication of beliefs. Similarly, in neuropsychiatric disorders abnormal and delusional beliefs appear to be caused by altered perception and/or misattribution of aversive meaning.
Conclusion.Given the importance of beliefs for ordinary social behaviour, abnormal beliefs are a challenge in neuropsychological disorders.Beliefs, a heavily discussed topic in Western philosophy since centuries, have gained an increasing interest in cognitive psychology in recent years. The neuroscientific study of beliefs has enjoyed recently a multi-level approach including neural, psychic, experiential, behavioural and social levels. In functional terms, beliefs have been defined as relatively stable accounts of what a subject holds to be true and to predict future events (Connors & Halligan, 2015). In neural processing terms, it has been proposed that in most cases one of the functions of beliefs is to integrate perceived signals in the environment with attribution of personal emotional value (