A 75-year-old man with seven years of formal education displayed a syndrome of progressive and severe lexical impairments to word comprehension and production (semantic dementia). While he lost the ability to recognize written arithmetical signs, he could still retrieve the arithmetical facts for addition and subtraction of all number combinations of 1 to 9 and 11 to 19, though his mastery of multiplication tables (2 to 9) was unreliable. Calculation procedures were intact. Over the course of 18 months the components of the calculation system dissolved selectively: arithmetical procedures and number reading were spared, despite increasing damage to the arithmetic fact store. He retained the ability to read the time on analogue clocks. Selective preservation of components of the calculation system in the context of severe language deficits and dementia, supports the independent status of numerical abilities. The dissociation between intact arithmetical procedures and impaired table fact retrieval was paralleled by a dissociation between preserved procedures of phonology and syntax of language and impaired retrieval of content words, suggesting that the core deficit was a degradation of the central semantic store of learned knowledge of both words and arithmetic table facts.

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Performance measurement in psychogeriatric patients does not provide full insight into their potential abilities (competence). By systematically varing environmental conditions, performance levels can be seen to vary with them. The experiment discussed here demonstrates the influence of movement therapy on the results of some psychological tests. The subjects were old people (average age 82 years) who at an advanced age were confronted with mental and physical handicaps of such a nature that they had to be admitted to a psychogeriatric nursing home. Forty patients were divided into two groups. Both groups were tested twice with an interval of one month. A control group was tested twice under identical circumstances. In the first test, both groups were examined under the same conditions. The second test of the exercise group took place shortly after the subjects had taken part in physical exercise. The psychological tests consisted of a free-recall task, a test for visuomotor coordination and a recognition task. The results showed that in the free-recall test the exercise group had improved more than the control group. A qualitative analysis of the free-recall and recognition performance seemed to suggest that the exercise group showed greater retrieval activity than the control group. Visuo motor abilities did not significantly vary under experimental conditions, though the observed changes were compatible with improved cognitive performance in the exercise group.

In this study 297 institutionalized patients with primary degenerative dementia were investigated. Age at onset of dementia was determined and individual longevity quotients (i.e. actual duration of survival divided by expected survival) were calculated. Expected survival was derived from the Dutch life tables for the general population. Age at onset of dementia was 75.6 +/- 7.8 years (mean +/- SD). Duration of dementia until death was 7.2 +/- 4.1 years. Dementia of early onset (before age 76) was associated with a significantly reduced life expectancy (LQ = 0.70 +/- 0.30), but this was not found for onset after age 75 (LQ = 0.91 +/- 0.58). Duration of symptoms at the time of admission into a nursing home was not associated with severity of behavioural and cognitive impairments as measured with behaviour rating scales. However, the severity of behavioural impairments predicted 1-year survival after admission, as could be shown by multivariate analysis which corrected for the effects of age and sex.

The suitability of Warrington's Recognition Memory Test (RMT) for discriminating between patients with dementia of the Alzheimer type and nondemented elderly subjects was tested in a study with 44 patients (aged 59 to 94) and 45 normal elderly (aged 69 to 92). The patients showed a significant memory deficit, both in Recognition Memory for Words (RMW) and Recognition Memory for Faces (RMF), even when the scores were corrected for verbal intelligence score (WAIS Vocabulary) or a measure of visuoperceptual ability (Raven's Coloured Progressive Matrices, CPM). Word-face discrepancy scores did not differentiate between dementia and normal old age. At the 95%-specificity level, the sensitivity of RMW and RMF for the detection of memory impairment in dementia was 81% and 100% for subjects below 80, and, less satisfactory, 59% and 76% for subjects of 80 years or older. Correlational analysis showed that the patients' RMW and RMF scores were moderately correlated (r = .40). The significant correlation (r = .45) between CPM and RMF suggests that visuoperceptual deficits are involved in deficient face recognition.