The odor of rat litter-mates was experimentally modified from 3-10, 11-18, or 22-29 days of age. Acetophenone or ethyl benzoate were used during the experimental period and the natural odor was present during the other two periods. After living in the natural odor colony for another 2 weeks, Ss were compared on duration of time near each olfactory stimulus animal in an eight hour test. Ss preferred the stimulus animal characterized by the experimental odor with which they were reared. Age of exposure was not a significant factor. These results indicate that the odor of the species is learned, that the intensity of the odor is important, but that age is not a critical variable in the early learning of the species odor in the rat.

Teachers planning undergraduate field experience programs will find here some problems, as well as some merits, requiring consideration.

No abstract

PROBLEMWhen psychological tests used with the general population for the detection of cerebral damage are applied to schizophrenic populations, many patients perform in a manner consistent with the presence of organicity. This study investigated whether these differential performances were related to any other differences among patients. Three matched groups of schizophrenics classified at three levels of probability of cerebral damage were compared on the process-reactive dimension. METHODSs were 90 male schizophrenics at Embreeville State Hospital, Coatesville, Pennsylvania, who were placed into three groups on the basis of performance on a battery of psychological tests of cerebral damage.The test battery consisted of the Bender Visual-Motor Gestalt Test, scored for cerebral damage according to the method of Hutt and Briskin@); the Memory-forDesigns Test, scored according to the manual of instructions(*); and the Trail Making Test, scored according to the normative data of Reitan"). On the basis of Ss' performances on this battery, three groups of 30 each were formed: Group A consisted of those not classified as brain-damaged by any of the three teats; Group B consisted of those classified as brain-damaged by one or two but not by all three of the teats; and Group C consisted of those classified ,as brain-damaged by each of the three tests in the battery.The means of the three groups were closely matched on the variables of chronological age, intelligence as measured by the WAIS Verbal IQ, and degree of chronicity as indicated by the number of years elapsed since first hospitalization. None of the group differences on these three variables approached significance as indicated by analyses of variance.As a measurement of the process-reactive dimension, the premorbid history section of the Phillips Scale was employed. In most research using this scale, schizophrenics have been divided into process and reactive groups on the basis of their scores. However, as Garmezy") points out, such a dichotomy is probably artificial. Instead, data in this study were analyzed as a process-reactive continuum.RESULTS AND DISCUSSION On the Phillips Scale, the mean score for Group A was 12.40 (SD = 6.42) ; the mean score for Group B was 19.53 (SD = 7.45) ; and the mean score for Group C was 23.93 (SD = 7.66). A one-way analysis of variance yielded an overall F ratio of 19.62, indicating significant group differences (p < .Ol). Further analysis of the data was accomplished using the Newman-Keuls method described by Wirier@).