Longitudinal dichotic listening patterns for aphasic patients : III. Relationship to language and memory variables

Longitudinal dichotic scores were obtained for aphasic patients for whom extensive language and memory data were also available. Severity of language impairments was related to ear advantage, but this occurred because larger lesions yielded more severe language impairments and were more likely to involve Heschl's gyrus. Extent of language recovery was not related to changes in ear dominance. Relationships that occurred generally supported a functional-anatomical interpretation which stressed the importance of the integrity of the posterior superior temporal lobe to performance both on dichotic tests and on specific language or memory tests.     

Longitudinal dichotic listening patterns for aphasic patients : II. Relationship with lesion variables

Dichotic listening scores and information on lesion size and location were obtained for aphasic patients. All patients had a reduction in dichotic scores at 1 month postonset of symptoms, but some patients returned to normal levels of performance by 6 months postonset. Lesion location was the main determinant of patterns of performance. Right ear scores from the dichotic digit test closely reflected the presence or absence of lesions involving Heschl's gyrus. What appeared to be an effect of lesion volume was confounded by the relationship between increasing lesion volume and a greater likelihood of damage to Heschl's gyrus.     

Food deprivation: Effects on the predatory behavior of southern grasshopper mice (Onychomys torridus)

The southern grasshopper mouse (Onychomys torridus) is a predatory and aggressive rodent native to the semi-arid scrub deserts of the southwestern United States and northern Mexico. Its natural diet consists primarily of arthropods and small vertebrates. In this study, we have evaluated the effects of food deprivation on the predatory behavior of adult male and female grasshopper mice to crickets (Acheta domesticus) and laboratory mice (Mus musculus). Subjects that were food-deprived for 48 hours spent more time eating dead but not living crickets than did controls that were provided free access to laboratory chow. There were no sex differences in the predatory behavior of grasshopper mice to living or dead crickets. Food deprivation also influenced the predatory behavior of grasshopper mice toward laboratory mice. With laboratory chow available ad lib, 6 of 43 (14%) male and 22 of 45 (49%) female grasshopper mice killed and ate laboratory mice within 48 hours of pairing. When deprived of food for 48 hours, 16 of 36 (44%) males and 15 of 19 (79%) females that did not kill in the previous experiment killed and ate laboratory mice. We concluded that food deprivation and type of prey are two variables which influence the frequency and intensity of predatory behaviors of grasshopper mice.