Anosognosia for memory loss

Anosognosia for memory loss is a common feature of degenerative disorders and acquired brain injuries that manifests as the lack of awareness of memory difficulties following injury to the brain. Patients who are unaware of their memory loss, might engage in riskier behaviours, have increased difficulties managing their medication and making appropriate medical decisions. Although many studies have investigated this disorder of awareness, the underlying mechanisms of anosognosia for memory loss remain unclear. Though methodological biases in measurement have been proposed for the variable findings across studies, it has become increasingly accepted that anosognosia is a multifaceted phenomenon.

The main aims of this thesis are (i) to provide a new measure for anosognosia for memory loss: a measure that attempts to improve on existing biases in current assessments; and (ii) to provide a comprehensive examination of anosognosia from a multifaceted framework. Specifically, this thesis provides an examination of psychological (personality and mood), cognitive and metacognitive (monitoring factors) and neuroanatomical factors (lesion mapping). Results from this thesis support (i) the new measure of anosognosia presented in this thesis as a valid and reliable tool that overcomes some of the common pitfalls of existing measures and that there are (ii) underlying multifactorial factors for anosognosia for memory loss. Indeed, psychological factors such as personality traits (decreased neuroticism trait); memory monitoring abilities (memory performance and source monitoring); and neuroanatomical factors (cerebellar lesions) were found to be associated with unawareness of memory loss. Findings are discussed with regard to their relevance on current theoretical models of anosognosia for memory loss.