Effects of neonatal administration of clomiphene citrate on sexual behavior of female rats: a preliminary report

Female rats were treated with the nonsteroidal estrogen antagonist clomiphene citrate for the first 5 days postpartum. The expectation was that clomiphene would influence the sexual development of these animals as is the case with sexually immature animals treated with steroidal compounds. Analysis showed that treatment with clomiphene completely disrupted the adult sexual behavior of the female. In five consecutive days of testing the experimental females were never observed to mate. They were mounted significantly less often than controls, suggesting that the males were less attracted to them than to normal females. The initial suggestion that clomiphene might affect the sexual behavior of females has been supported; however, further research must be done to identify the underlying mechanism of the change.     

Systems approach to the concept of niche

Conclusion The systems approach to niche presented herein stands as an example of the unifying potential of mathematical system theory when applied to concepts and principles of ecology. Beginning with subjective concepts from the naturalistic tradition, the niche was framed in the formalism of general system theory. So modeled, it appeared as a restriction of a more general construct, the environ. Both niches and environs are implementable in the context of ecosystem models, and with the growing ability of ecologists to construct such models, system theoretic niches and environs both should serve in the future to clarify old problems of ecology, and make it possible to raise new classes of problems. The nature of niches, always difficult conceptually for the ecologist, may now give way to further development, both theoretical and empirical.     

Graphemic analysis underlying literacy

Three experiments are described that studied the role of detailed graphemic analysis upon the ability to read text. College students named letters in various approximations to English, with frequency of individual letters constant. Findings were that later skill at reading varied with the order of approximation to English of the letters that were named, that the spacing of the letter sequences was important to this result, and, finally, that the influence of specific visual practice extended to the typeface on which the naming and reading were carried out. Hence, rather than a letter-by-letter process or its opposite, a wholly semantic analysis, reading is shown to be intimately dependent upon details of visual analysis of patterns or letter sequences.     

Representation of inflected nouns in the internal lexicon

The lexical representation of Serbo-Croatian nouns was investigated in a lexical decision task. Because Serbo-Croatian nouns are declined, a noun may appear in one of several grammatical cases distinguished by the inflectional morpheme affixed to the base form. The grammatical cases occur with different frequencies, although some are visually and phonetically identical. When the frequencies of identical forms are compounded, the ordering of frequencies is not the same for masculine and feminine genders. These two genders are distinguished further by the fact that the base form for masculine nouns is an actual grammatical case, the nominative singular, whereas the base form for feminine nouns is an abstraction in that it cannot stand alone as an independent word. Exploiting these characteristics of the Serbo-Croatian language, we contrasted three views of how a noun is represented: (1) the independent-entries hypothesis, which assumes an independent representation for each grammatical case, reflecting its frequency of occurrence; (2) the derivational hypothesis, which assumes that only the base morpheme is stored, with the individual cases derived from separately stored inflectional morphemes and rules for combination; and (3) the satellite-entries hypothesis, which assumes that all cases are individually represented, with the nominative singular functioning as the nucleus and the embodiment of the noun’s frequency and around which the other cases cluster uniformly. The evidence strongly favors the satellite-entries hypothesis.     

A comparison of the reliability and validity of the standard MFF and MFF20 with learning-disabled children

A direct comparison was made of the reliability and validity of the standard Matching Familiar Figures Test (MFF) to a recent longer version of the task (MFF20). Subjects comprised two samples of learning-disabled children, matched on age, sex, IQ, and SES. The Salkind and Wright (1977) formulation was used to generate continuous data, and IQ was statistically controlled. Internal reliability estimates showed the MFF20 to be more consistent that the standard version on both error and latency scores. Validity was addressed by comparing the two versions of the task in their ability to predict cognitive and behavioral skills of conceptual relevance to impulsivity. Results indicated that the MFF20 is a more sensitive predictor of academic achievement and attention as observed in a natural setting than is the standard version of the task.This study was supported by a contract (300-77-0495) from the Bureau of Education for the Handicapped, Office of Education, for the University of Virginia Learning Disabilities Research Institute. The authors would like to express appreciation to the school officials who generously assisted in the present study: Elizabeth Bailey, Thomas Cox, Charles Dempsey, Julian King.     

Word-finding as a function of stimulus context: Children compared with aphasic adults

A study of object naming in 202 children, aged 5–11 years, demonstrated that varying the stimulus context affected the level of response accuracy. From age 6 to 10, completing a sentence with a noun (auditory) yielded the lowest error scores, naming objects upon hearing a definition (also auditory) produced most errors, while responding with names to pictured objects was of intermediate difficulty. This is the same order of object naming difficulty found in adult aphasic patients. Children older than 10 do not appear to be affected by stimulus context in their object naming. Results are discussed in terms of the relative syntactic difficulty of the two auditory conditions, the unexpected sex differences, and the “aphaseoid” naming errors of children.     

Pupillometric assessment of retrieval operations in factual long-term memory

The process involved in recall from long-term memory were studied through the use of a general knowledge questionnaire and the technique of pupillometry. Degree of processing of the components of the retrieval process was inferred from second-by-second monitoring of pupil size. Measurements were recorded during subjects' attempts to retrieve the answer to the query, or if unsuccessful, from clues of the target (first and last letters), and if still unsuccessful, to recognize the presented target word as being associated with the question (the “Of course”, or “That's it!” experience). Pupil size differed according to the nature of the three task demands. Additionally, there were differences based on the type of outcome within the question trial (e.g., between target known but blocked — feeling-of-knowing/tip-of-tongue — and target not known), and the answer trial (recognize vs not recognize the question—answer relationship). The results were related to the search and decisional processes of retrieval.     

A reexamination of sex differences in job preferences

Previous research has found conflicting answers to the question of whether males and females share similar preferences for various job characteristics. It is difficult to determine if the different findings are due to the different populations sampled, the various methodologies employed, or to a real change in the phenomenon itself. This study essentially replicates earlier work by having 130 male and 84 female college students rate the importance of 10 job characteristics for both themselves and members of the opposite sex. Both sexes rated motivators as important, but females also placed importance on the hygienes. Males tended to underestimate the importance of the motivators for females, while females overestimated the importance of hygienes for males. The subject's sex could be predicted by both the importance for self and importance for opposite sex ratings, contrary to the earlier study. The difference in results and interpretation was shown to be due to the type of analyses used. Additionally, it was found that females' job preferences were related to their mothers' educational achievement.