A method for studying visually guided perception and learning in newborn macaques

A maintenance technique was developed in which neonatal monkeys obtain all liquid food by placing their heads in a face mask mounted on their cage wall. Complete self-feeding required only 3-6 days for animals started at birth. Once under a self-feeding Schedule, operant responses were shaped to study visual perception, visually guided motor performance, and discrimination learning at ages much younger than those allowed by most alternative methods. Dark rearing, with the only source of visual input being through the face mask eyeholes, allowed the E to control completely the neonate’s visual experiences and its opportunities for visual-motor responding. The method has proven useful in rhesus monkey newborns for studying adaptation to prismatic displacement at 30 days of age, and to performance on CRF, FI, and FR reinforcement schedules.     

Responsibility diffusion and drive enhancement effects on risky shift1

Discussion produced expected risky and cautious shifts on choice dilemma items It was predicted from responsibility diffusion theory that, compared with low-anxious, high-defensive groups, high-anxious, low-defensive groups produce greater risky shift It was predicted from drive enhancement theory that, compared with low-anxious groups, high-anxious groups produce greater risky shift on risk-dominant items and greater cautious shift on caution-dominant items The results of two experiments failed to confirm either interpretation Surprisingly, significant shifts were obtained in a control condition     

The time required to compare extents in various orientations

In Experiment I, Ss compared the lengths of lines that varied in absolute and relative orientation. Their reaction times showed a constant error pattern of which the familiar horizontal-vertical illusion was a special case, but horizontals were underestimated (relative to other slopes) much more than verticals were overestimate. The effect of difference inorientation was not great, though RT did increase significantly as the difference neared 90 deg. Experiment II was similar except that the lengths of lines were compared withthe widths of bars in a grating. In this case, no consistent pattern of constant error emerged, and there was no suggestion that difference in orientation affected RT.     

Change and stability in sexism among college students: A three-year panel study

Results are reported of a 3-year panel study of sex-role attitude changes among Ball State University students. Two questions were posed: (1) To what extent do students change their sex-role attitudes? (2) What types of students are more likely to change their attitudes? Contrary to expectations, students did not become progressively less sexist each year they were in college. Apparently, changes in student sex-role attitudes were more reflective of changes in local public opinion rather than following the Bennington College pattern. An important finding of the study is that those who were initially the most sexist displayed the greatest degree of change in their attitudes. A mixed pattern prevails with regard to relationships between changes in attitudes and background characteristics, personal orientations, and political orientations.     

Human neuropsychology: Some differences between korsakoff and normal operant performance

Summary Operant reinforcement schedules were used to investigate the effects of changes in reinforcement rates on the behavior of alcoholic Korsakoff (amnesic) patients and normal control subjects. In one test, both groups were exposed to pairs of variable-interval (VI) reinforcement schedules which operated concurrently. The distribution of reinforcements controlled the distribution of responses of normal subjects to a significantly greater extent than those of the Korsakoff patients. In a second test, two VI reinforcement schedules were arranged to run one at a time in succession. Reinforcement-rate differences with the successive (multiple) schedules did not produce corresponding response-rate differences for either group of subjects. The findings stress the complexity of the alcoholic Korsakoff syndrome, and emphasize the need to consider possible motivational abnormalities as determinants of alcohol-induced amnesia. In addition, results underscore both the value and the limitations of using operant procedures in human learning research.Supported in part by PHS Grants NS 07615 and NS 06209, by PHS RCDA K04 NS 00161 to M. O. Berman, and by the Medical Research Service of the Veterans Administration. Address offprint requests to M.O. Berman, BVAMC, 150 So. Huntington Ave., Boston, MA. 02130, USA     

Is Natural Kindness a Natural Kind?

Philosophical Studies -