The numbers and distribution of the neurofibrillary tangles and neuritic plaques have been determined in several areas of the neocortex in brains affected by various degrees of severity of Alzheimer disease. The homotypical cortex of the "association" areas of the temporal, parietal, and frontal lobes are severely involved, whereas the motor, somatic sensory, and primary visual areas are virtually unaffected. The neurofibrillary tangles are mainly in the supra-and infragranular layers, particularly in layers Ill and V. In all areas except area 18 in the occipital lobe, there are approximately twice as many tangles in layer V as in layer III. The tangles are arranged in definite clusters, and those in the supra-and infragranular layers are in register. The neuritic plaques occur in all layers but predominantly affect layers II and Ill and do not show clustering. These data on the severity of the pathological involvement in different areas of the neocortex and the laminar distribution and the clustering of the tangles support the suggestion that the pathological changes in Alzheimer disease affect regions that are interconnected by well-defined groups of connections and that the disease process may extend along the connecting fibers. The invariable and severe involvement of the olfactory areas of the brain in this disease is in striking contrast to the minimal changes in the somatic sensory and primary visual areas and raises the possibility that the olfactory pathway may be initially involved.

The number of neuronal cell bodies has been counted in a narrow strip (30 micrometers) through the depth of the neocortex in several different functional areas (motor, somatic sensory, area 17, frontal, parietal and temporal and in many species (mouse, rat, cat, monkey and man). With the exception of area 17 of the visual cortex in a number of primates the same absolute number (congruent to 110) of neurons has been found in all areas and in all species. In the binocular part of area 17 of the primates there are approximately 2.5 times more neurons. Thus in mammalian evolution the area of the neocortex increases in larger brains but the number of neurons through the depth remains constant, except in area 17 of primates. From these and other findings it is suggested that the intrinsic structure of the neocortex is basically more uniform than has been thought and that differences in cytoarchitecture and function reflect differences in connections.

This paper describes the Rivermead Behavioural Memory Test (RMBT)-a short test of everyday memory problems with four parallel forms. It was administered to 118 control subjects aged between 16-69 years with a mean IQ of 106 (range 68-136). The limit of normal performance was established on this group and cut-off points were determined for individual components of the test. The test was also given to 176 brain-damaged people and its validity assessed both by correlating RMBT scores to performance on existing tests, to subjective ratings from patients and carers and to observation by therapists of memory lapses. Validity, parallel form and interrater reliability all proved to be high. It is concluded that the RBMT is a short, reliable, and valid test of everyday memory problems.

Recent patterns of fertility in Europe show marked differences between countries. Recent United Kingdom and Irish fertility curves show 'distortions' in terms of a 'bulge' in early age fertility, distinct from the smoother curves of other European countries. These patterns may not be adequately described by mathematical functions used by previous studies to model fertility curves. A mixture model with two component distributions may be more appropriate. The suitability of the simple and mixture Hadwiger functions is examined in relation to the fertility curves of a number of European countries. While the simple Hadwiger model fits recent period age-specific fertility distributions for some countries, others which display a 'bulge' in early age fertility distributions for some countries, others which display a 'bulg' in early age fertility require a mixture Hadwiger model. Some of the parameters of the Hadwiger models appear to be related to familiar demographic indices. The simple and mixture Hadwiger models appear useful in describing and comparing fertility patterns across European countries.