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901.
This paper explores some of the ethical (and legal) implications of artificial insemination and in vitro fertilization. In both cases the emphasis is on the interests of the potential child. It concludes that in neither case is great optimism or great pessimism appropriate. About AID, much of the legal and ethical concern has been other than child-centered, and has focused mainly on the interests of parents and donors. Three aspects expecially remain troubling: donor selection, record-keeping and disclosure and the testing of frozen semen. About further IVF research, approval appears justified, as long as remaining concerns about risk/safety and need are satisfied.  相似文献   
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Prototype theory construes membership in a concept's extension as graded, determined by similarity to the concept's “best” exemplar (or by some other measure of central tendency). The present paper is concerned with the compatibility of this view of concept membership with two criteria of adequacy for theories of concepts. The first criterion concerns the relationship between complex concepts and their conceptual constituents. The second concerns the truth conditions for thoughts corresponding to simple inclusions.  相似文献   
904.
The study assessed children's responsiveness to adults of both sexes as a function of the adults behavior. Paris of male and female adults administered games to 96 children. Each child was assigned to either the modeling, praise, or collaboration condition. Depending on the condition, each adult, in turn, (a) modeled selection of a specific set of play materials, (b) praised the child for playing with the materials, or (c) collaborated with the child while they played together with the materials. Results showed a greater responsiveness to the same-sex adult in the collaboration condition and to the cross-sex adult in the praise condition, as measured by the time spent playing with the materials previously associated with each adult and by comments to each adult. In the modeling condition, there was a nonsignificant same-sex effect for children's actual responsiveness, but a significant same-sex effect for self-reported responsiveness. Sex-typing scores, which were independently assessed, were related to same-sex responsiveness in the collaboration condition only. Different, and perhaps complementary, influences of same-sex and cross-sex adults on children's sex-typed preferences are considered.  相似文献   
905.
A pair of experiments investigated the short-term memory of pigeons under delayed simple and conditional discriminations. Trial sequences in both discriminations consisted of a color as the sample stimulus, a memory interval, a line orientation as the test stimulus, and a trial outcome, which was either food reinforcement or blackout. Pecking rates during the test stimulus defined discrimination performance. In the simple discrimination, the sample provided the necessary information regarding the subsequent trial outcome. In the conditional discrimination, the sample and test stimuli conjointly provided this information. In Experiment 1, the two procedures were compared with independent groups of pigeons. In Experiment 2, the comparison was made within subjects. The simple discrimination was acquired more quickly and was performed better with a memory requirement. Introduction of long delays disrupted performance even at shorter delays in both discriminations. Postulation of prospective as well as retrospective mediating processes facilitates the interpretation of these results.  相似文献   
906.
Using a modified Stroop procedure, we examined the extent to which the semantic encoding of a word is governed by the context within which that word appears. Good and poor comprehenders named the color of target words following their reading of either sentences or single words representing the object nouns of the sentences. Target words represented contextually emphasized (appropriate) attributes of the object nouns, nonemphasized (inappropriate) attributes of these nouns, or object attributes not related to these nouns (neutral). For single-word contexts, all subjects exhibited equal semantic interference to appropriate and inappropriate targets, relative to neutral targets. For sentence contexts, however, good comprehenders exhibited semantic interference only to appropriate targets, whereas poor comprehenders again exhibited equal interference to appropriate and inappropriate targets. These findings suggest that differences in comprehension skill may be attributable, at least in part, to fundamental differences in the way in which sentences are semantically encoded.  相似文献   
907.
Eleven diagnosed Broca's aphasics were tested for comprehension of sentences containing gerundive constructions. Results showed that, as a group, these patients were sensitive to grammatical distinctions signaled by “function” words, contrary to the predictions of some current theories about the specific deficits exhibited in this syndrome. Further analysis showed that the patients fell into two subgroups, one which exhibited sensitivity to the distinctions in normal grammar, and another which exhibited no sensitivity to such distinctions. This suggests that the syndrome may have different manifestations in different populations—patient age is suggested as a possible means for distinguishing the two groups. Suggestions for further research into the nature of the comprehension deficits exhibited by Broca's aphasics are made.  相似文献   
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