Affiliations: [a] Municipal Hospital of Bremen-Ost, Department of Neurology, Bremen, Germany | [b] University of Oldenburg, Clinical and Health Psychology, Oldenburg, Germany | [c] University of Nijmegen, Department of Psychology, NICI, Nijmegen, The Netherlands
Correspondence:
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Corresponding author: Helmut Hildebrandt, Ph.D., Klinikum Bremen Ost, Department of Neurology, Züricher Str. 40, 28325 Bremen, Germany. Tel.: +49 421 408 1599; Fax: +49 421 408 2599; E-mail: helmut.hildebrandt@uni-oldenburg.de.
Abstract: Severe memory impairment forms the core symptom of Alzheimer's disease (AD), which is present early in the disease course. Recent studies show that AD patients not only suffer from forgetfulness, but also differ in their response bias, when having to decide whether information has been perceived recently, or whether it is only familiar or semantically related to perceived information. Changes in total tau-protein and amyloid-β (Aβ)1–42 concentration in cerebrospinal fluid are also features of AD, and they predict conversion from mild cognitive impairment to dementia. In this study we correlated recognition scores with total tau and Aβ1–42 concentrations in patients with suggested dementia. We studied 40 patients and 21 healthy controls, using an incidental recognition memory task and a neuropsychological test battery. False recognition scores correlated with delayed recall and with Aβ1–42, and Aβ1–42 tended to correlate with delayed recall. Total tau, however, did not correlate with memory scores or with neuropsychological performance in general. We suggest that Aβ1–42 may indicate a reduction in the specificity of the neuronal response in the limbic cortex, due to agglomeration of plaques. This process might be more specific for AD than the increase of tau, and therefore it is stronger correlated with recognition errors.
Keywords: Amyloid-β1–42, dementia, false recognition, memory, total tau
