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.     

Rapid processing of the meaning of sentences

It has been shown (Fischler & Bloom, 1979) that sentence contexts facilitate a lexical decision task for words that are highly likely sentence completions and inhibit the decision for words that are semantically anomalous sentence completions. In the present experiment, the sentence contexts were presented 1 word at a time, at rates from 4 to 28 words/sec. The facilitation for words that were likely sentence completions was marginal at the slower rates and absent at higher rates. In contrast, the inhibitory effects of semantic anomaly were apparent at all presentation rates. Several analyses suggested that the sentence contexts were becoming ineffective at the very highest presentation rates, but the high rates at which the sentence contexts still affected word recognition were taken as evidence that semantic information accrues at an early stage of sentence processing. Implications for Posner and Snyder’s (1975) theory of attention and for models of reading were discussed.     

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.     

Prevalence and constituency of behavioral disturbance taxonomies in the regular school population

The Bristol Social Adjustment Guides (BSAG) are widely employed in research and in the identification of maladjustment in school children. The BSAG provides scores on several indices including five homogeneous behavioral syndromes and one associated grouping. Field experience suggests that maladjusted children frequently manifest problems in more than one syndrome. In order to discover what patterns of syndromic profiles may commonly exist among children, the data for the most recent revision of the BSAG are reanalyzed. The syndrome scores for all 2,527 5- to 15-year-old regular school children in the standardization sample were grouped into similar profile patterns by hierarchical cluster analysis. Sixteen homogeneous syndromic profile types emerged. The resultant profile types were described on the basis of their component behaviors and examined for membership trends by sex and age groups. Multiple syndromic profiles represented 60% of all maladjusted children.The author wishes to thank Dr. Denis H. Stott, former professor of psychology at the University of Guelph, Ontario, for kindly making the Bristol Social Adjustment Guides data available for this study.     

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.     

Very rapid forgetting

Human forgetting can be much more rapid than previous experiments have indicated. Subjects who do not expect a test after a filled retention interval can rarely recall three consonants correctly after 2 sec of distraction. If there are two kinds of memory, primary and secondary, the present technique provides a purer method of studying forgetting from primary memory.     

Completion norms for 329 sentence contexts

Completion responses were collected for two sets of sentence contexts, which were designed to produce different distributions of probabilities for the primary responses. The subject population consisted of undergraduate college students. For each context, responses and their respective probability of occurrence are listed, and an index of the primary responses is provided. It is hoped that these normative materials will facilitate comparison among future studies of the effects of sentence contexts on word processing.