The effects of atropine on viscerovisceral reactions and the electrocardiogram of the cat

In 12 chronic cats the effects of mechanical stimulation (distention) of the gallbladder on heart rate, respiratory movements and bioelectrical activity of the cerebral cortex were studied under normal conditions and after intraperitoneal administration of atropine. In the control group without atropine a decrease or an increase of heart rate and of respiratory movements occurred, depending on stimulation intensity. These changes were independent of an activated or inactivated EKG. Behavioral arousal was not seen in every cat. After administration of atropine in doses from 0.2 to 2.0 mg per kg body weight, the changes in heart rate, respiration and EKG were suppressed or completely disappeared.     

Perceptual invariance and the psychophysical law

The psychophysical power law, demonstrated empirically by Stevens, is derivable from two postulates concerning (1) the tendency of perceptual organizations to model the environment and (2) the tendency for perceptual relations to remain constant. The two postulates appear to rule out logarithmic laws of the Fechner type. The theory is extendable to multidimensional perceptions such as those encountered in speech and color vision. The power transformations produced by the sense organs may be of such form that they produce a perceptual space in which subsequent transformations need be only linear.     

A latent class model for rating data

A latent class model for rating data is presented which is the analogue of Andrich's binomial Rasch model for Lazarsfeld's latent class analysis (LCA). The response probabilities for the rating categories follow a binomial distribution and depend on class-specific item parameters. The EM-algorithm for parameter estimation as well as goodness of fit tests for the model are described. An example using questionnaire items on interest in physics illustrates the use of the model as an alternative to the latent trait approach of analyzing test data.I would like to thank Clifford Clogg and the anonymous reviewers for their helpful comments.     

Electrophysiologic studies of alcohol dependent patients

Electrophysiological methods were used to examine 52 ward patients with a long history of alcohol abuse. Alertness fluctuations were much more common in the EEG than among the healthy control subjects. 86.5% of the ENG findings were abnormal and indicated demyelinisation in most cases. The latence times of the brain stem potentials were longer than normal in about half of the patients and were definitely pathological in 13.5%. There was no statistical correlation between drinking habits and the results of the examination. Unknown pathogenetic factors are therefore suspected. The polytopic pattern of damage necessitates the use of a broad range of signostic techniques.     

Neurophysiologic findings in chronic alcohol abuse

Neurophysiological examinations of 100 long term alcohol dependent patients who were having neuropsychiatric treatment, showed symptoms of polytopic damage of the peripheral and central nervous system. The results show that for recognition of the damage an extensive diagnostic programme must be used.     

The dissociation of position and extent in Müller-Lyer figures

Three experiments were designed to determine whether Müller-Lyer figures cause a misperception of the positions of their fins and, if they do, whether it is commensurate with the distortion of extent. Observers marked the visible intersection of shaft and fins either with their unseen hands or with their visible hands after the figure had been removed from view. In the former case, no systematic distortions of position were evident. In the latter case, there were small, systematic distortions of position, which were significantly smaller when the observers fixated the target vertex than when they fixated the center of the figure. These differences are discussed in terms of the probable similarities between the control of eye movements and the control of pointing responses. Of particular importance is the finding that even the largest distortions of vertex position were much smaller than the distortions of shaft extent. The results appear to provide evidence of the independence of perceived position from perceived extent in Müller-Lyer figures and to contradict all existing theories of the illusion.