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Repeated measurements of episodic memory are needed for monitoring amnestic mild cognitive impairment (aMCI) and mild Alzheimer's disease (AD). Most episodic memory tests may pose a challenge to patients, even when they are in the milder stages of the disease. This cross-sectional study compared floor effects of the Visual Association Test (VAT) and the Rey Auditory Verbal Learning Test (RAVLT) in healthy elderly controls and in patients with aMCI or AD (N = 125). A hierarchical multiple regression analysis was used to examine whether linear or quadratic trends best fitted the data of cognitive test performance across global cognitive impairment. Results showed that VAT total scores decreased linearly across the range of global cognitive impairment, whereas RAVLT total scores showed a quadratic trend, with total scores levelling off for 90% of aMCI patients and 94% of AD patients. We conclude that the VAT shows few if any floor effects in patients with aMCI and mild AD and is therefore a potentially promising cognitive test for monitoring episodic memory impairment.

Patients with mild cognitive impairment (MCI) do not always convert to dementia. In such cases, abnormal neuropsychological test results may not validly reflect cognitive symptoms due to brain disease, and the usual brain-behavior relationships may be absent. This study examined symptom validity in a memory clinic sample and its effect on the associations between hippocampal volume and memory performance. Eleven of 170 consecutive patients (6.5%; 13% of patients younger than 65 years) referred to memory clinics showed noncredible performance on symptom validity tests (SVTs, viz. Word Memory Test and Test of Memory Malingering). They were compared to a demographically matched group (n = 57) selected from the remaining patients. Hippocampal volume, measured by an automated volumetric method (Freesurfer), was correlated with scores on six verbal memory tests. The median correlation was r = .49 in the matched group. However, the relation was absent (median r = -.11) in patients who failed SVTs. Memory clinic samples may include patients who show noncredible performance, which invalidates their MCI diagnosis. This underscores the importance of applying SVTs in evaluating patients with cognitive complaints that may signify a predementia stage, especially when these patients are relatively young.

We investigated the size of repetition priming effects from young-old to very old age using a newly developed Word-Stem Completion (WSC) task. Retrospectively, we examined the role of explicit, intentional retrieval strategies in priming. We constructed our task by taking factors into account that were known to complicate the measurement of significant and valid priming effects. Within our sample of 170 cognitively healthy elderly persons of 55-94 years old, we found no effects on priming of age, gender, education, intelligence, cognitive status, memory complaints, or depressive symptoms. Participants that subsequent to task administration reported awareness of the study-test relationship obtained higher priming scores. However, analysis of stem-completion times showed that explicit contamination during the task was unlikely. The results suggest that WSC priming is age-invariant up to very old age. This task with increased validity might contribute to the differentiation with Alzheimer's disease by improving specificity of assessment.

Validation studies of symptom validity tests (SVTs) in children are uncommon. However, since children's cognitive abilities are not yet fully developed, their performance may provide additional support for the validity of these measures in adult populations. Four SVTs, the Test of Memory Malingering (TOMM), the Word Memory Test (WMT), the Amsterdam Short-Term Memory (ASTM) test, and the Word Completion Memory Test (WCMT), along with several neuropsychological instruments were administered to 48 Dutch school children aged 7-12. All children scored above the established adult cut-offs on the TOMM and the WMT. They could pass the ASTM test if their reading skills were at a level equivalent to that of 9 year olds. All children passed our criterion of a negative WCMT score. However, the WCMT does seem sensitive to the level of verbal fluency. Implications for the applicability of these SVTs in adult populations are discussed.

Many studies have evaluated the utility of the Word Memory Test (WMT) as a symptom validity test. However, there is a lack of reference data for the WMT conventional memory subtests. The present study examined the demographic characteristics that influence performance on these subtests, in order to develop demographically corrected reference data. For this purpose, we administered the Dutch version of the WMT to 115 healthy Dutch controls, aged 20-80 years. Furthermore, we demonstrated the equivalence of the English and Dutch language versions of the WMT. Stepwise linear regression analyses of the combined Canadian and Dutch samples (N = 155) showed that the memory scores declined with increasing age. Participants with lower levels of education performed worse than more highly educated subjects. Reference data stratified by age and level of education are presented for use in research and clinical settings.

A broad memory test battery (reflecting explicit and implicit memory functioning) was administered to a heterogeneous sample of initially nondemented, community-dwelling elderly subjects. To examine the profile of preclinical dementia, subjects were tested twice: At baseline, all subjects were nondemented according to Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) criteria; 2 years later, a subgroup had developed dementia. Performance of the preclinically demented subjects was best characterized, relative to that of cognitively impaired subjects who did not develop dementia 2 years later, by an inability to benefit at recall from semantic relations and by absent repetition priming effects. The authors conclude that in addition to testing episodic memory functioning, it is important to be aware of semantic and implicit memory deficits in the early assessment of dementia., (Copyright (c) 2005 APA, all rights reserved.)

This paper reviews research findings concerning memory performance in Alzheimer's disease (AD) and normal ageing. Studies using clinical (i.e., episodic) memory tests are compared with studies using various experimental memory paradigms (semantic memory, implicit memory, working memory), in order to determine their efficiency to differentiate between AD and normal ageing. In addition, attention is focused on early and preclinical AD. It is argued that traditional clinical memory tests alone are not best able at detecting AD at an early stage. More specifically, tasks calling upon semantic knowledge may aid to an earlier and more efficient assessment of AD.