Seeing things as people: anthropomorphism and common-sense psychology

This thesis is about common-sense psychology and its role in cognitive science. Put simply, the argument is that common-sense psychology is important because it offers clues to some complex problems in cognitive science, and because common-sense psychology has significant effects on our intuitions, both in science and on an everyday level. The thesis develops a theory of anthropomorphism in common-sense psychology. Anthropomorphism, the natural human tendency to ascribe human characteristics (and especially human mental characteristics) to things that aren't human, is an important theme in the thesis. Anthropomorphism reveals an endemic anthropocentricity that deeply influences our thinking about other minds. The thesis then constructs a descriptive model of anthropomorphism in common-sense psychology, and uses it to analyse two studies of the ascription of mental states. The first, Baron- Cohen et al. 's (1985) false belief test, shows how cognitive modelling can be used to compare different theories of common-sense psychology. The second study, Searle's (1980) `Chinese Room', shows 'that this same model can reproduce the patterns of scientific intuitions taken to systems which pass the Turing test (Turing, 1950), suggesting that it is best seen as a common-sense test for a mind, not a scientific one. Finally, the thesis argues that scientific theories involving the ascription of mentality through a model or a metaphor are partly dependent on each individual scientist's common-sense psychology. To conclude, this thesis develops an interdisciplinary study of common-sense psychology and shows that its effects are more wide ranging than is commonly thought. This means that it affects science more than might be expected, but that careful study can help us to become mindful of these effects. Within this new framework, a proper understanding of common-sense psychology could lay important new foundations for the future of cognitive science

Respiratory syncytial virus and parainfluenza type 3 virus infections in cattle

Respiratory diseases are economically important in the U.K. Those which affect young, immature, housed calves have been difficult to define in aetiological terms despite many years of research. Many viruses, bacteria and mycoplasmas have been associated with these diseases but in recent years the pathogenic roles of respiratory syncytial virus and parainfluenza type 3 virus have demanded particular attention. The aim of this thesis was to investigate the part played by these two viruses in the respiratory diseases of cattle with particular reference to the pathogenesis, diagnosis and differential diagnosis of these two infections in naturally occurring outbreaks of disease. These primary aims were to be accompanied by attempts to produce viral infection in experimental calves using isolates of the viruses obtained during the field investigations. A multidisciplinary investigation into 22 outbreaks of acute respiratory disease in immature cattle was carried out using clinical, microbiological and pathological techniques. Eight outbreaks were detected in which there was unequivocal evidence of infection with either RS virus or PIS virus. In addition 16 individual cases of RS viral infection and one case of PIS viral infection v/ere detected in material referred from Veterinary Investigation Centres in England. Common clinical findings in RS viral cases were hyperpnoea, tachypnoea and, in severe cases, dyspnoea. On pathological examination there v/as pneumonia involving the cranial parts of the lung lobes and, in fatal cases, severe interstitial emphysema with the formation of gas-filled bullae in the caudal lobes. Microscopically syncytium formation in the epithelia of the bronchioles, the alveoli and, very occasionally, the bronchi was found. Virus-infected cells sometimes contained eosinophilic intracytoplasmic inclusion bodies. Three new strains of RS virus were recovered during these investigations. Relatively few individual cases of PIS viral infection were discovered, however, in these there was also inclusion body formation in the cytoplasm of respiratory epithelial cells and, occasionally, epithelial syncytia were present. Secondary bacterial infection was common with Pasteurella multocida and Pasteurella haemolytica types A1 and A2 involved, Due to the similar nature of the specific pathological changes due to RS viral and PIS viral infections it was found necessary to develop a technique which could distinguish between these two infections in the lung. Immunofluorescent staining of viral antigens in either acetone-fixed or formalin-fixed sections of pneumonic lung was developed for this. The detection of antigens in lung which was been fixed for conventional histopathology was a significant advance on previous techniques as it enabled the relationship between the viral antigens and the histopathological changes to be assessed more fully. Experimental infections were carried out using RS virus and PIS virus. Unfortunately it was not possible to use the isolates of RS virus which had been recovered during the field investigations. Using an RS virus isolate obtained from a another laboratory calves were successfully infected. Combined infection with the cattle lungworm Dictyocaulus viviparus was attempted in order to potentiate the effects of the viral infection. Although viral infection was established there was no unequivocal evidence that this was increased in severity by concomitant D.viviparus Infection. Two groups of calves, one aged two weeks and the other four months, were infected with a recent field isolate of PIS virus. In both groups viral infection was associated with clinical signs of respiratory disease and pathological lesions, specifically recognisable as being due to PIS viral infection, were produced in the lower respiratory tract

Diagnostic accuracy of the Enferplex Bovine TB antibody test using individual milk samples from cattle

Bovine tuberculosis is usually diagnosed using tuberculin skin tests or at post-mortem. Recently, we have developed a serological test for bovine tuberculosis in cattle which shows a high degree of accuracy using serum samples. Here, we have assessed the performance of the test using individual bovine milk samples. The diagnostic specificity estimate using the high sensitivity setting of the test was 99.7% (95% CI: 99.2-99.9). This estimate was not altered significantly by tuberculin boosting. The relative sensitivity estimates of the test using the high sensitivity setting in milk samples from comparative skin test positive animals was 90.8% (95% CI: 87.1-93.6) with boosting. In animals with lesions, the relative sensitivity was 96.0% (95% CI: 89.6-98.7). Analysis of paired serum and milk samples from skin test positive animals showed correlation coefficients ranging from 0.756-0.955 for individual antigens used in the test. Kappa analysis indicated almost perfect agreement between serum and milk results, while McNemar marginal homogeneity analysis showed no statistically significant differences between the two media. The positive and negative likelihood ratio were 347.8 (95% CI: 112.3-1077.5) and 0.092 (95% CI: 0.07-0.13) respectively for boosted samples from skin test positive animals. The results show that the test has high sensitivity and specificity in individual milk samples and thus milk samples could be used for the diagnosis of bovine tuberculosis.</p