Does glucagon enhance opacification of the bile ducts during intravenous cholangiography? An experimental study in dogs.

To determine the rational for the ability of glucagon to enhance opacification of the bile ducts during intravenous cholangiography, which has been claimed in recent clinical reports, experiments were performed in dogs which had had Thomas cannulas inserted. A constant step-wise infusion of iodipamide was administered with or without a bolus injection and constant infusion of glucagon. At every infusion rate of iodipamide the biliary concentration of the contrast agent was less when glucagon was administered. Glucagon caused a choleresis, but had no effect on the rate of excretion of iodipamide. It is concluded that the theory that glucagon is of value to improve opacification of the bile ducts during intravenous cholangiography is unlikely to be confirmed by further clinical trials.

Reversible perspective figures and eye movements.

Eye movements and perspective reversals were continuously recorded on film for 9 subjects who fixated a central point on black line drawings of the Necker cube and Rubin vase figure. There were significantly more Necker cube reversals than Rubin figure reversals in the 1 1/2-min. test periods. Perceptual reversals were unrelated to the occurrence of eye movements but appear possibly to be related to the perceived tridimensionality of the figures.

Perceptual stability, image size, binocularity and creativity.

24 male and female Ss, divided into three groups of 8 Ss each on the basis of their creativity test scores, were tested under fully counterbalanced conditions involving three sizes of Necker cubes, viewed under both monocular and binocular conditions. The response measure was number of figure of reversals experienced during 2-min. viewing periods for each set of conditions. Image size was statistically significant, while creativity levels and viewing conditions were not.

Comprehension and appreciation of humorous material following brain damage.

The effects of brain damage on cognitive and affective status have been assessed separately; however, a dearth of information exists about the interaction of these facets in the brain-damaged patient. Because appreciation of humour involves both cognitive and affective dimensions, an investigation of response to humorous materials should yield information relevant to this issue. In addition, a study of response to humour in aphasic patients can reveal the extent to which appreciation of humour is dependent upon an intact language system. Accordingly a test of humour, in which an individual chose the "funniest" of four cartoons, was administered to a population of brain-damaged and control patients. Ability to detect the most humorous cartoon was impaired in all brain-damaged patients, more in severe than in mild aphasics, but there was no significant difference between patients with left and right hemisphere lesions in their overall performance on the test. A different order of difficulty across items, and a different profile of "mirth" responses to the items did, however, correlate with site of lesion. Right hemisphere patients tended either to laugh throughout or, more frequently, not at all; they often confabulated answers to made impossible inferences; and they performed better on items with captions. Their cognitive reactions appeared "dissociated" from their affective responses. In contrast left hemisphere patients performed better on the captionless items and behaved in a manner which more closely approximated normal subjects in their humorous reactions, their order of item difficulty, and their explanations. All brain-damaged patients found it relatively easier to locate the humorous cartoons when the members of a set differed appreciably from one another. These results provide information about the altered cognitive and affective states of brain-damaged patients, the impairment of cognitive operations in aphasic patients, and the respective "life-spaces" of left and right hemisphere injured patients.