The study explored differential patterns of deficits in different memory components as a function of dementia severity. Three groups of 58 subjects each were used: (1) highly functioning elderly who are free of neurological or psychiatric symptoms; (2) individuals with early signs of memory disturbance, whose MMSE scores were > or = 24; and (3) individuals with MMSE scores below 24, who meet criteria for DAT. Performance on the tests that assess different memory components was compared for the three groups. Results suggest pronounced change in acquisition component of memory at the onset of dementia, whereas retrieval from remote memory discriminates well between the mild and the more advanced phases of the disease. Retrieval from recent memory deteriorates more gradually. Based on these results, efficiency of different memory mechanisms was discussed.

This study explored the relationship between three indices of intersubtest scatter and level of cognitive deterioration in a sample of 104 patients with dementia of Alzheimer's type, who ranged in age between 52 and 84 years. Scatter was highly related to education and premorbid level of functioning. Advancement of dementia was shown to be associated with decrease in scatter, which suggests caution in interpretation of high magnitude of inter-subtest scatter as an indication of brain dysfunction. Easy-to-calculate range of scatter proved to be adequate measure of scatter. Calculation of more complex indices, such as PVI, provides only minimal incremental gain.

The study explored encoding, storage, and retrieval components of memory functioning in four groups of subjects: (1) normal elderly; (2) elderly subjects in the early prestages of DAT; (3) elderly subjects with a more advanced DAT; (4) younger subjects in the early prestages of AIDS dementia. Each group consisted of 26 subjects, who were administered the Rey Auditory-Verbal Learning Test. The results suggest impaired encoding and retrieval in the DAT groups. The AIDS group demonstrated deficient storage and retrieval. Their pattern of memory deficits was similar to that seen in normal aging. The results speak in favor of the hypothesis of subcortical nature of neurological changes in normal aging.

In the course of the preparatory work for the WHO cross-cultural study on the neuropsychiatric aspects of HIV-I infection, two new neuropsychological tests (the WHO/UCLA Auditory Verbal Learning Test and the Color Trails 1 & 2) were developed. The evaluation of these tests was performed at four sites, two in developed and two in developing countries. The data obtained suggest that the tests are more culture fair than others currently used to assess the same functional domains, that they are sensitive to HIV-1-associated cognitive impairment, and that this sensitivity "holds" across different cultures.