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.

Keywords:

• Memory
• Awareness
• Insight
• Metacognition
• Metamemory.

ACKNOWLEDGEMENTS

We are indebted to Simon Lovestone and Laura Bach for their assistance in recruitment of Alzheimer and brain injury patients, respectively. The authors would like to thank the participants and their families for their keen involvement in this study.

FUNDING

This study was funded through a Medical Research Council studentship and grants from the Alzheimer’s Research Trust. The authors acknowledge support from the Department of Health via the National Institute for Health Research (NIHR) Specialist Biomedical Research Centre for Mental Health award to South London and Maudsley NHS Foundation Trust (SLaM) and the Institute of Psychiatry at King’s College London.