The role of memory in awareness of memory deficits in Alzheimer’s disease, schizophrenia, and brain injury

Abstract

Patients with neuropsychiatric disorders such as Alzheimer's disease (AD), schizophrenia (Sz), and brain injury (BI) often show memory deficits and lack of awareness of those deficits. This study aimed to investigate the role of memory in awareness of memory deficits and illness in multiple patient groups. Comparison of awareness profiles between groups can reveal common or distinct patterns of awareness and predictors, which may inform theories about the structure of awareness. Using the same standardized measures, AD (N = 27) Sz (N = 31), and BI (N = 26) patients were compared on memory functioning, awareness of illness, and awareness of memory deficits-measured by discrepancy of pretest estimate and actual test scores. All groups were poor at pretest estimation of memory functioning, particularly the AD and BI groups. In AD, patients with the lowest memory functioning rated their performance highest. The BI group and to a lesser extent the AD group showed improved estimations of performance following the memory test. Those with the poorest memory showed the greatest improvement in ratings accuracy post test. The relationship between memory and awareness of memory was stronger than the association between memory and awareness of illness. There was a double dissociation between awareness of memory and awareness of illness across patient groups. The study shows that awareness of memory is linked to memory functioning, while memory is only modestly related to awareness of illness. Dissociations in the role of memory in different domains of awareness and "online" awareness of performance provide information to refine cognitive models of awareness. However, the results should be interpreted with caution given the heterogeneous nature of the sample.

Awareness of memory deficits in subjective cognitive decline, mild cognitive impairment, Alzheimer's disease and Parkinson's disease

“…In the present study, the strongest associations were observed between awareness and the domain memory, which, however, is at least partly due to the operationalization of awareness scores, which included a subtest of the domain memory. Nevertheless, this finding is in line with prior research indicating that awareness of memory is specifically linked to memory functioning (Gilleen et al, 2014). Yet, further small but significant correlations were also observed for the domains attention, language and executive function (controls/SCD/naMCI/aMCI), which suggests that memory is not the only cognitive domain influencing memory awareness.…”

Could cognitive estimation ability be a measure of cognitive reserve?

“…Given these findings, we hypothesize that assessing cognitive estimation abilities might be considered a reliable strategy for measuring important aspects of cognitive reserve: in fact, it could be used as a measure of the person's body of knowledge and experiences (Della Sala et al, 2004 ), independently from aging (Della Sala et al, 2004 ; MacPherson et al, 2014 ), and—at the same time—as a sensitive instrument for assessing certain cognitive domains such as working memory and semantic knowledge (D'Aniello et al, 2015 ). The hypothesis that semantic knowledge is part of the cognitive estimation ability would be confirmed by studies relative to patients with Alzheimer's Disease (Della Sala et al, 2004 ; Levinoff et al, 2006 ; Barabassy et al, 2007 ; Khodarahimi and Rasti, 2011 ), Mild Cognitive Impairment (Levinoff et al, 2006 ), and Korsakoff's syndrome (Taylor and O'Carroll, 1995 ; Brand et al, 2003 ), in which higher amount of errors in the estimation process comparing to healthy groups were reported.…”

“…According to our model, if the primary output from the reasoning process is not put through the monitoring stage and, for example, it is not checked with further everyday information (Shallice and Evans, 1978 ), but is directly provided as a result of the estimation, the final output would be a bizarre answer: it is an unreasonable and extremely inaccurate answer which was generally interpreted as a clue of pervasive impairment in cognitive estimation (Della Sala et al, 2003 ). Besides in previous studies relating to cognitive estimation (Appollonio et al, 2003 ; Khodarahimi and Rasti, 2011 ) less attention was generally given to bizarre answers (probably due to some difficulties in outlining an operational and actionable definition of the bizarreness index) it could be considered a remarkable clue about the executive domains involvement in the estimation ability: indeed Parkinson's disease (Appollonio et al, 2003 ), fronto-temporal dementia (Mendez et al, 1998 ), and focal frontal lesions (Shallice and Evans, 1978 ; Taylor and O'Carroll, 1995 ; MacPherson et al, 2014 ), but also schizophrenia (Khodarahimi and Rasti, 2011 ) and major depressive disorder patients (Barabassy et al, 2010 ) reported a poor performance in the cognitive estimation ability, and specifically an higher number of bizarre answers, since the lack of efficacy of executive functions involved in the cognitive estimation process.…”

Investigation of metamemory functioning in the at-risk mental state for psychosis

“…Patients with schizophrenia have been found to have a higher KCI compared to controls (Moritz et al , 2006c, i.e. Patients with the lowest memory performance seem to be most impaired in metamemory abilities (Gilleen et al 2014). In addition to findings in verbal memory tasks, knowledge corruption has also been found in source-monitoring tasks (Gaweda et al 2012(Gaweda et al , 2013.…”