Quantitative and qualitative analyses of clock drawings in Alzheimer's and Huntington's disease.

Although visuoconstructive impairment has been reported in both Alzheimer's (DAT) and Huntington's (HD) disease, there is little knowledge concerning how this cognitive deficit differs quantitatively and qualitatively in these two progressive dementias. To address this issue, the present study compared performances on the Clock Drawing Test (CDT: command and copy) of 25 DAT patients, 25 equally demented HD patients, and 25 elderly normal controls (NC). In the command condition, both patients groups were significantly impaired compared to the NC group. Although there was no significant difference between DAT and HD patients' total quantitative scores, a qualitative error analysis revealed a number of dissociations between the two patient groups. Graphic difficulties, very common in HD patients, were virtually absent in DAT patients; in contrast, conceptual errors were almost exclusively seen in DAT patients and were related to the severity of their dementia. Perseveration and "stimulus-bound" responses were also more frequent in DAT patients, and both groups made visuospatial errors. In the copy condition, the DAT, but not the HD, patients evidenced a marked improvement in performance. These results indicate that while both DAT and HD patients have significant visuoconstructive difficulties even in the early stages of their disorders, the specific cognitive processes underlying their quantitative impairments are quite different. It is possible that the DAT patients' conceptual errors are yet another indicator of the deterioration of their semantic knowledge.     

Memory with and without awareness: performance and electrophysiological evidence of savings.

Event-related potentials (ERPs) recorded on the scalp were shown to be sensitive indicators of the strength of a memory trace on both implicit and explicit tests of memory. In explicit recognition tests, the amplitude of a positive potential identified as P300 was larger for "old" than for "new" words regardless of whether the subject categorized the items correctly. This effect, however, was statistically reliable only when the recognition memory (d') was relatively high. In contrast to ERPs, the reaction times in explicit recognition were sensitive to accuracy but not to repetition. In implicit tests, lexical decisions to repeated words were faster than to newly presented words. The magnitude of the repetition effect varied neither with elapsed time since the last repetition nor with the number of previous repetitions. In contrast, the P300 elicited by the same words were sensitive to both lag and recency of repetition, suggesting that they were influenced by the episodic memory strength of the items.     

Dominance,sex, and leader emergence

A 3×2×2 incomplete factorial design was employed to test the effects of sex, dominance, and their interaction on leader emergence. The factors included dominance distribution (high/high, high/low, middle/middle), sex (male-female), and dyad composition (mixed sex-same sex). The subjects were all Caucasians and were pretested on the California Psychological Inventory Dominance Scale. The data revealed that dominance was a predictor of leader emergence in same-sex conditions where high-dominant individuals assumed the role of leader in much greater proportions than their low-dominant partners. In mixed-sex dyads, sex appeared to be a more potent predictor with males becoming leaders at levels greater than would be suspected given dominance levels.     

Spatial cognition and neighborhood use: the relationship in older adults.

Measures of spatial cognition, neighborhood knowledge, and neighborhood use from the research described by Walsh, Krauss, and Regnier (1981) were examined to determine if laboratory tests of spatial cognition were significant predictors of older adults' use of their neighborhoods. The overall results show that laboratory-based measures of spatial cognition and subjects' knowledge of their neighborhoods are both significant predictors of their use of neighborhood goods and services. The ability to learn and remember the location and orientation of objects, when contextual cues were not provided at test, was more predictive of the participants' neighborhood use than either the participants' number of years in the neighborhood or their mobility. Spatial memory as measured by the Educational Testing Service Building Memory task predicted neighborhood knowledge, which was predictive of neighborhood use.     

Age-related differences in three tests of visual imagery.

Adult age differences were explored on 3 short tests of the ability to generate and manipulate mental images. Age-related decrements were found in all 3 tests and were especially marked on the Clock Test. The tests are all reliable, as shown by test-retest reliability coefficients. Correlations also revealed that the Brooks Letter Test and the East-West Test appear to tap one common underlying ability, whereas the Clock Test measured a somewhat different ability. The East-West and Clock tests, in particular, may provide rapid and easily administered assessments of age-related changes in aspects of mental imagery.     

Crime and the elderly: a review of British and American research

Research into the victims of crime is of fairly recent origin and has been centred in America. However, a review of research into the experience of the elderly as the victims of crime, and their anxiety about crime, reveals a paradox. Numerous studies show that while the elderly are less likely to be the victims of crime than are the other age groups, they are among those who exhibit most anxiety over crime. The research is discussed in the context of theories of why the elderly appear as a low-risk group and in terms of an attempt to explain the paradox.     

Relevance reviewed: The case of argumentum ad hominem

This article aims tt providing some conceptual tools for dealing adequately with relevance in argumentative discourse. For this purpose, argumentative relevance is defined as a functional interactional relation between certain elements in the discourse. In addition to the distinction between interpretive and evaluative relevance that can be traced in the literature, analytic relevance is introduced as an intermediary concept. In order to classify the various problems of relevance arising in interpreting, analyzing and evaluating argumentative discourse, a taxonomy is proposed in which the concept of relevance is differentiated along three co-ordinate dimensions: object, domain and aspect. With the help of this taxonomy, it can be shown that the problems of evaluative relevance with which the standard approach to fallacies cannot satisfactory deal can be more systematically approached within a pragma-dialectical framework. This is demonstrated for the argumentum and hominem, which is erroneously treated as a homogenous type of relevance fallacy in logico-centric analyses, so that cases where this is not justified must be treated as ad hoc exceptions.     

Ivan Pavlov on communist dogmatism and the autonomy of science in the Soviet Union in the early 1920s. 1923.

On 25 September, 1923, two days before his 74th birthday, Ivan Petrovich Pavlov stood before a class of medical students assembled in the auditorium of his Alma Mater, the Military Medical Academy in Leningrad. Pavlov, the recipient of the Nobel prize in medicine in 1904 for his work in physiology, was about to address his first class of the new academic year, and, as was his custom, he had prepared his first lecture on a general theme. This was an especially significant address, however, for in it Pavlov reviewed the impressions he had gathered during his travels in Western Europe and the United States in the summer of 1923, and he criticised the prevailing ideology of Soviet communism by attacking the ideas of Nikolai Ivanovich Bukharin, then the leading expositor of Bolshevik Marxism. An English translation of the lecture is printed below.