Memory impairment and awareness of memory deficits in early-stage Alzheimer's disease.
Recognition memory of auditory verbal learning tests and awareness of memory deficits were examined in 24 individuals with early-stage Alzheimer's disease (AD) using a performance prediction-postdiction paradigm. Individuals with AD displayed impaired recognition memory, and recognition performance correlated positively with regional cerebral blood flow at rest in bilateral prefrontal areas and the left medial temporal area. In addition, underawareness of memory deficits was also marked even at this early stage. Individuals with AD retrospectively overestimated memory performance after actual performance, but appeared to benefit from feedback, and displayed intact online awareness of memory dysfunction, leading to normal prediction of the second session. However, individuals with AD failed to retrospectively incorporate incidents of memory failure into generalized self-belief systems. Brain/ behavior correlational analyses suggest that the prefrontal cortex and posterior dorsomedial regions including the precuneus may be involved in self-awareness.
Mimura
Masaru
M
Department of Neuropsychiatry, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8666, Japan. mimura@med.showa-u.ac.jp
Yano
Madoka
M
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000523:psychology*; D001364:Awareness / Q000502:physiology*; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D006624:Hippocampus / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007859:Learning Disabilities / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000523:psychology; D008297:Male; D008569:Memory Disorders / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000523:psychology*; D008959:Models, Neurological; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000503:physiopathology; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D017397:Prefrontal Cortex / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon