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991.
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. 相似文献
992.
993.
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. 相似文献
994.
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. 相似文献
995.
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. 相似文献
996.
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. 相似文献
997.
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. 相似文献
998.
999.
The roles which word class (open/closed) and sentential stress play in the sentence comprehension processes of both agrammatic (Broca's) aphasics and normal listeners were examined with a word monitoring task. Overall, normal listeners responded more quickly to stressed than to unstressed items, but showed no effect of word class. Aphasics also responded more quickly to stressed than to unstressed materials, but, unlike the normals, responded faster to open than to closed class words regardless of their stress. The results are interpreted as support for the theory that Broca's aphasics lack the functional underlying open/closed class word distinction used in word recognition by normal listeners. 相似文献
1000.
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. 相似文献