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.