Characteristics of motor resonance predict the pattern of flash-lag effects for biological motion

Background - When a moving stimulus and a briefly flashed static stimulus are physically aligned in space the static stimulus is perceived as lagging behind the moving stimulus. This vastly replicated phenomenon is known as the Flash-Lag Effect (FLE). For the first time we employed biological motion as the moving stimulus, which is important for two reasons. Firstly, biological motion is processed by visual as well as somatosensory brain areas, which makes it a prime candidate for elucidating the interplay between the two systems with respect to the FLE. Secondly, discussions about the mechanisms of the FLE tend to recur to evolutionary arguments, while most studies employ highly artificial stimuli with constant velocities. Methodology/Principal Finding - Since biological motion is ecologically valid it follows complex patterns with changing velocity. We therefore compared biological to symbolic motion with the same acceleration profile. Our results with 16 observers revealed a qualitatively different pattern for biological compared to symbolic motion and this pattern was predicted by the characteristics of motor resonance: The amount of anticipatory processing of perceived actions based on the induced perspective and agency modulated the FLE. Conclusions/Significance - Our study provides first evidence for an FLE with non-linear motion in general and with biological motion in particular. Our results suggest that predictive coding within the sensorimotor system alone cannot explain the FLE. Our findings are compatible with visual prediction (Nijhawan, 2008) which assumes that extrapolated motion representations within the visual system generate the FLE. These representations are modulated by sudden visual input (e.g. offset signals) or by input from other systems (e.g. sensorimotor) that can boost or attenuate overshooting representations in accordance with biased neural competition (Desimone & Duncan, 1995).

Prevalence of alcohol consumption and pattern of use among the elderly in the WHO European Region

BACKGROUND/AIMS: Alcohol-related problems are relevant in the elderly, particularly in developed countries, but there is a lack of cross-country comparisons. The present work aims to examine the frequency and patterns of alcohol consumption in older adults across different European countries, and to analyze the relationship between socioeconomic status and gender with alcohol consumption. METHODS: General population-based household surveys of randomly selected adults over 60 years of age in 14 European countries. PARTICIPANTS: 10,119 subjects [mean age: 70.4 (SD = 7.1)], 61.9% women. RESULTS: There are marked differences in alcohol consumption across countries. Except for three countries from eastern regions, most people in all countries present moderate consumption regarding the amount of alcohol and pattern of use. However, there are marked gender differences, with a higher intake in men (effect sizes ranging from 0.57 to 1.27), although these differences are relatively proportional across countries. Finally, a higher socioeconomic status is positively related (B = 0.845, 95% CI: 0.30/1.40) with alcohol consumption after controlling for gender, age, health-functioning status and the country's development level. CONCLUSIONS: There are marked differences in consumption of alcohol in the elderly between the different countries, and male gender, as well as a higher SES, were associated with higher alcohol consumption.

Semi-supervised construction of general visualization hierarchies

We have recently developed a principled approach to interactive non-linear hierarchical visualization [8] based on the Generative Topographic Mapping (GTM). Hierarchical plots are needed when a single visualization plot is not sufficient (e.g. when dealing with large quantities of data). In this paper we extend our system by giving the user a choice of initializing the child plots of the current plot in either interactive, or automatic mode. In the interactive mode the user interactively selects ``regions of interest'' as in [8], whereas in the automatic mode an unsupervised minimum message length (MML)-driven construction of a mixture of GTMs is used. The latter is particularly useful when the plots are covered with dense clusters of highly overlapping data projections, making it difficult to use the interactive mode. Such a situation often arises when visualizing large data sets. We illustrate our approach on a data set of 2300 18-dimensional points and mention extension of our system to accommodate discrete data types.

The spatial pattern of the vacuolation ('spongiform change') in the cerebral cortex in variant Creutzfeldt-Jakob disease (vCJD)

The spatial pattern of the vacuolation ('spongiform change') was studied in areas of the cerebral cortex in 11 cases of variant Creutzfeldt-Jakob disease (vCJD). The vacuoles were evenly distributed along the cortex in 40/106 (38%) areas studied and randomly distributed in 6/106 (5.6%) areas. In 22/106 (21%) areas, the vacuoles were aggregated into clusters, 50 - 1600 μm in diameter and which were distributed in a regular pattern parallel to the pia mater. In 38/106 (36%) areas, large clusters of vacuoles, at least 1600 μm in diameter, were present. No significant differences in spatial patterns were observed between the different cortical regions or between the upper and lower laminae. In addition, age at onset and duration of the disease had no significant affect on spatial patterns. The spatial distribution of the vacuolation contrasts with that reported in sporadic CJD (sCJD) suggesting a different pattern of cortical degeneration in vCJD.

Spatial pattern of prion protein deposits in patients with sporadic Creutzfeldt–Jakob disease

The spatial pattern of the prion protein (PrP) deposits was studied in the cerebral cortex and cerebellum in 10 patients with sporadic Creutzfeldt–Jakob disease (CJD). In all patients the PrP deposits were aggregated into clusters and, in 90% of cortical areas and in 50% of cerebellar sections, the clusters exhibited a regular periodicity parallel to the tissue boundary; a spatial pattern also exhibited by ß-amyloid (Aß) deposits in Alzheimer's disease (AD). In the cerebral cortex, the incidence of regular clustering of the PrP deposits was similar in the upper and lower cortical laminae. The sizes of the PrP clusters in the upper and lower cortex were uncorrelated. No significant differences in mean cluster size of the PrP deposits were observed between brain regions. The size, location and distribution of the PrP deposit clusters suggest that PrP deposition occurs in relation to specific anatomical pathways and supports the hypothesis that prion pathology spreads through the brain via such pathways. In addition, the data suggest that there are similarities in the pathogenesis of extracellular protein deposits in prion disease and in AD.

The spatial pattern of senile plaques, neurofibrillary tangles and A4 deposits in Alzheimer's disease

The spatial patterns of senile plaques (SP) and neurofibrillary tangles (NFT) as visualised using the Gallyas stain and of discrete A4 protein deposits were determined in coronal serial sections from a variety of brain regions in six elderly patients with Alzheimer's disease (AD). These lesions showed clustering in virtually all tissues examined with many of the clusters being regularly spaced. These spatial patterns were compared with the clustering observed for SP and NFT stained by the Glees and Marsland method in the same tissues. The data suggest that on average, while the regular clusters of A4 deposits and NFT were of approximately the same mean diameter (3600 microns), clusters of both Glees and Gallyas SP were approximately half this diameter (1800 - 2000 microns). If SP develop in local areas of the brain where both A4 deposition and neurofibrillary changes have occurred, the data suggest that the SP clusters would represent the region of overlap of the A4 deposits and neurofibrillary changes. Various hypothese are advocated to explain the regular clsuetring of the A4 deposits.

The spatial pattern of the vacuolation in patients with sporadic Creutzfeldt-Jakob disease

The spatial pattern of the vacuolation ('spongiform change') was studied in the upper and lower laminae of the cerebral cortex, the CA1/CA2 sectors of the hippocampus and the molecular layer of the cerebellum in 11 cases of sporadic Creutzfeldt-Jakob disease (CJD). Individual vacuoles were grouped into clusters, 50 to >1600 μm in diameter and, in the majority of tissue sections, the vacuole clusters were distributed with regular periodicity parallel to the tissue boundary. The size of the vacuole clusters was positively correlated with patient age in the lower laminae of the occipital cortex and the inferior temporal gyrus (ITG) and negatively correlated with age in the hippocampus. In addition, the size of the vacuole clusters was positively correlated with disease duration in the upper laminae of the ITG. The size and distribution of the vacuole clusters suggests that the vacuolation in CJD reflects the degeneration of specific brain pathways and supports the hypothesis that prion pathology may spread through the brain along well defined anatomical pathways. (C) 2000 Elsevier Science Ireland Ltd.

The spatial pattern of discrete beta-amyloid deposits in Alzheimer's disease reflects synaptic disconnection

The spatial pattern of discrete beta-amyloid (A beta) deposits was studied in the superficial laminae of cortical fields of different types and in the hippocampus in 6 cases of Alzheimer's disease (AD). In 41/42 tissues examined, discrete A beta deposits were aggregated into clusters and in 34/41 tissues (25/34 of the cortical tissues), there was evidence for a regular periodicity of the A beta deposit clusters parallel to the tissue boundary. The dimensions of the clusters varied from 400 to > 12,800 microns in different tissues. Although the A beta deposit clusters were larger than predicted, the regular periodicity suggests that they develop in relation to groups of cells associated with specific projections. This would be consistent with the hypothesis that the distribution of discrete A beta deposits in AD could reflect progressive synaptic disconnection along interconnected neuronal pathways. This implies that amyloid deposition could be a response to, rather than a cause of, synaptic disconnection in AD.

The spatial pattern of beta-amyloid (Abeta) deposits in Alzheimer’s disease patients is related to apolipoprotein genotype

The spatial patterns of the diffuse, primitive, and classic beta-amyloid (Abeta) deposits was studied in the frontal and temporal cortex in cases of Alzheimer’s disease (AD) expressing different apolipoprotein (Apo E) genotypes. No significant differences in the density of the three Abeta deposit subtypes were observed in individuals expressing genotypes e2/3 and e3/3 compared with those expressing e3/4 and e4/4. In all patients, Abeta deposit subtypes occurred in the tissue in clusters. Chi-square contingency analyses of the data suggested that the cluster size of the diffuse and classic Abeta deposits was unrelated to Apo E genotype. However, the primitive (‘neuritic’) type Abeta deposits occurred more frequently in smaller, denser clusters in individuals expressing genotypes e3/4 and e4/4 compared with those expressing e2/3 and e3/3. Hence, the presence of the e4 allele may be associated with a more specific pattern of neuronal degeneration in the frontal and temporal cortex in AD.

The relationship between the spatial pattern of senile plaques and neurofibrillary tangles in Alzheimer's disease

The topographic pattern of senile plaques (SP) and neurofibrillary tangles (NFT) was studied in silver stained coronal sections of neocortex and hippocampus in ten cases of Alzheimer's disease (AD). Both lesions showed evidence of clustering in the tissue with many of the clusters being regularly spaced. The patterns of SP and NFT were compared 1) in the same cortical zone, 2) between upper and lower zones of the cortex and 3) in regions connected by either association fibres or the perforant path. Correlations between the lesions in the same cortical zone were found in 20% of the layers examined while correlations between upper and lower zones occurred in 64% of cortical regions examined. There was evidence that NFT in upper and lower cortex may be in register in some tissues. In addition, positive correlations were found between upper NFT and lower SP and negative correlations between upper SP and lower NFT in some tissues. Regular clustering of lesions was also observed in brain regions connected to one another suggesting that they develop on functinally related sets of neurons.

The influence of aspect on the pattern of saesonal growth in the lichen Parmelia glabratula ssp. fuliginosa (Fr. ex Duby) Laund

The radial growth of samples of thalli of Parmelia glabratula ssp. fuliginosa were measured in situ on a south-facing and a northwest-facing rock surface each month from August 1973 to July 1974. In the periods August to October 1973 and March to July 1974 the radial growth of thalli in the northwest population was greater than in the south population. In the period November 1973 to February 1974 the radial growth of thalli in the south population was greater than in the northwest population. A physiological basis for the differences in seasonal growth in the two populations was suggested. The mean annual radial growth rate (in units of mm/year) was not significantly different in the two populations. However, the variability in radial growth rate between thalli was signifiacntly larger in the northwest than in the south population. These results may be explained by genetic difference between the populations and environmental differences between the rock surfaces.

Density and spatial pattern of β-amyloid (Aβ) deposits in corticobasal degeneration

Corticobasal degeneration (CBD) is a rare, progressive movement disorder characterized neuropathologically by widespread neuronal and glial pathology including tau-immunoreactive neuronal cytoplasmic inclusions (NCI), oligodendroglial inclusions (GI), and astrocytic plaques (AP). However, ß -amyloid (A ß) deposits have been observed in the cerebral cortex and/or hippocampus in some cases of CBD. To clarify the role of Aß deposition in CBD, the densities and spatial patterns of the Aß deposits were studied in three cases. In two cases, expressing apolipoprotein E (APOE) genotypes 2/3 or 3/3, the densities of the Aß deposits were similar to those in normal elderly brain. In the remaining case, expressing APOE genotype 3/4, Aß deposition was observed throughout the cerebral cortex, sectors CA1 and CA2 of the hippocampus, and the molecular layer of the dentate gyrus. The densities of the Aß deposits in this case were typical of those observed in Alzheimer's disease (AD). In the three cases, clustering of Aß deposits, with clusters ranging in size from 200 to >6400 µm in diameter, was evident in 25/27 (93%) of analyses. In addition, the clusters of Aß deposits were regularly distributed parallel to the tissue boundary in 52% of analyses, a spatial pattern similar to that observed in AD. These results suggest: (1) in some CBD cases, Aß pathology is age-related, (2) more extensive Aß deposition is observed in some cases, the density and spatial patterns of the Aß deposits being similar to AD, and (3) extensive deposition of Aß in CBD may be associated with APOE allele e4.

Density and spatial pattern of the neuropathological changes in the cerebellum in the prion disease variant Creutzfeldt-Jakob disease (vCJD)

The objective of this chapter is to quantify the neuropathology of the cerebellar cortex in cases of the prion disease variant Creutzfeldt-Jakob disease (vCJD). Hence, sequential sections of the cerebellum of 15 cases of vCJD were stained with H/E, or immunolabelled with a monoclonal antibody 12F10 against prion protein (PrP) and studied using quantitative techniques and spatial pattern analysis. A significant loss of Purkinje cells was evident in all cases. Densities of the vacuolation and the protease resistant form of prion protein (PrPSc) in the form of diffuse and florid plaques were greater in the granule cell layer (GL) than the molecular layer (ML). In the ML, vacuoles and PrPSc plaques, occurred in clusters which were regularly distributed along the folia, larger clusters of vacuoles and diffuse plaques being present in the GL. There was a negative spatial correlation between the vacuoles and the surviving Purkinje cells in the ML and a positive spatial correlation between the clusters of vacuoles and the diffuse PrPSc plaques in the ML and GL in five and six cases respectively. A canonical variate analysis (CVA) suggested a negative correlation between the densities of the vacuolation in the GL and the diffuse PrPSc plaques in the ML. The data suggest: 1) all laminae of the cerebellar cortex were affected by the pathology of vCJD, the GL more severely than the ML, 2) the pathology was topographically distributed especially in the Purkinje cell layer and GL, 3) pathological spread may occur in relation to a loop of anatomical projections connecting the cerebellum, thalamus, cerebral cortex, and pons, and 4) there are differences in the pathology of the cerebellum in vCJD compared with the M/M1 subtype of sporadic CJD (sCJD).

The impact of general intellectual ability and white matter volume on the functional outcome of patients with bipolar disorder and their relatives

Background: There is substantial evidence that cognitive deficits and brain structural abnormalities are present in patients with Bipolar Disorder (BD) and in their first-degree relatives. Previous studies have demonstrated associations between cognition and functional outcome in BD patients but have not examined the role of brain morphological changes. Similarly, the functional impact of either cognition or brain morphology in relatives remains unknown. Therefore we focused on delineating the relationship between psychosocial functioning, cognition and brain structure, in relation to disease expression and genetic risk for BD. Methods: Clinical, cognitive and brain structural measures were obtained from 41 euthymic BD patients and 50 of their unaffected first-degree relatives. Psychosocial function was evaluated using the General Assessment of Functioning (GAF) scale. We examined the relationship between level of functioning and general intellectual ability (IQ), memory, attention, executive functioning, symptomatology, illness course and total gray matter, white matter and cerebrospinal fluid volumes. Limitations: Cross-sectional design. Results: Multiple regression analyses revealed that IQ, total white matter volume and a predominantly depressive illness course were independently associated with functional outcome in BD patients, but not in their relatives, and accounted for a substantial proportion (53%) of the variance in patients' GAF scores. There were no significant domain-specific associations between cognition and outcome after consideration of IQ. Conclusions: Our results emphasise the role of IQ and white matter integrity in relation to outcome in BD and carry significant implications for treatment interventions. © 2010 Elsevier B.V.