Contribution of conditioned opioid analgesia to the shock-induced associative US-preexposure deficit     

Louis D. Matzel  Steve C. Hallam  Ralph R. Miller 《Learning & behavior》1988,16(4):486-492

The modulatory effect of conditioned opioid analgesia on learning in the US-preexposure paradigm was examined in three experiments using water-deprived rats. In Experiment 1, it was found that tailflick latencies increased immediately after the rats were exposed to a context in which footshock had previously been administered. Prolonged nonreinforced exposure to the context attenuated this analgesia. Experiment 2 tested the possibility that the effectiveness of CS-US pairings in an excitatory context might be reduced by a conditioned analgesic response that lessens the perceived intensity of the US. Administration of the opiate antagonist naloxone prior to CS-US pairings in the excitatory context reduced the US-preexposure deficit—that is, the retarded response to the CS—but did not eliminate it, suggesting that part of the observed deficit resulted from conditioned activation of the endogenous opioid system. In Experiment 3, it was found that exposure to the excitatory context immediately prior to a CS-US pairing in an associatively neutral context resulted in a conditioned response deficit, indicating that the analgesia elicited by the excitatory context was sufficient to reduce US effectiveness. In combination with other recent reports, these results suggest that the associative deficit resulting from preexposure to a shock US may, in certain instances, represent the sum of several different associative processes.  相似文献   

CS-duration and partial-reinforcement effects counteract overshadowing in select situations     

Urushihara K  Miller RR 《Learning & behavior》2007,35(4):201-213

Two experiments used rats in a conditioned lick suppression preparation to investigate how the conditioned stimulus (CS)-duration and partial-reinforcement effects (i.e., weakened responding due to conditioning with a CS of longer duration and presenting nonreinforced CSs intermingled with CS—unconditioned stimulus [US] pairings, respectively) interact with overshadowing. Experiment 1 found that when overshadowing treatment was combined with either extended CS duration or partial reinforcement, the response deficit was weaker than when either of these three treatments was administered alone. In Experiment 2, the generality of the findings in Experiment 1 was investigated by replicating it with various US—US intervals. This time counteraction was observed only when both the absolute duration of total CS exposure and the US—US interval were short. The results support neither the view that the ratio between the total CS exposure and total time in the context determines the CS-duration and the partial-reinforcement effects nor the view that these two effects arise from a loss of effectiveness of the excitatory CS—US association during CS-alone exposures in partial reinforcement or early periods of CS exposure with long CSs.  相似文献   

ODS Network ‐ International School Networking     

Ralph Ballier  Klaus Füller 《Educational Media International》2013,50(3):126-130

Abstract

The initiative ‘Offenes Deutsches Schul‐Netz’ (ODS) ‐ The Open German School Network ‐ sees itself as a joint cover for school networking in Germany. In this article, we give an insight into the very successful ideas on which ODS is based. Practically every computer‐mediated communication between schools in Germany and abroad is transmitted on the basis of agreements by the ODS with various servers. We describe, briefly, how we imagine networking between schools in future.  相似文献   

What succeeds with an audience is bad     

Ralph Waldo Emerson Thoreau 《Quarterly Journal of Speech》2013,99(1)

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Changes in Relationship Between Teachers and Pupils Necessitated by a New Emphasis in Religious Education     

Ralph P. Bridgman 《Religious education (Chicago, Ill.)》2013,108(4):289-291

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On the electrical and anomalous scattering of mesotrons     

Ralph P. Shutt 《Journal of The Franklin Institute》1942,234(2):195-196

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“Maybe so — but count me out”     

Ralph N. Schmidt 《Communication quarterly》2013,61(2):4-5

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An activity‐centered alternative to teacher education     

Ralph Erickson 《The Teacher Educator》2013,48(1):5-7

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Modern poetry and a Kat called Krazy     

Ralph Pomeroy 《Communication quarterly》2013,61(3):14-15

This essay uses the nature of the genre of apologia as outlined by speech communication scholars as a framework to examine Richard Nixon's apology to the nation on the occasion of his resignation. Mr. Nixon conformed well to the requirements of the subgenre, explanation, but erred in areas not suggested in contemporary writings on apologia. The gravity of Nixon's misdeeds and the incongruity of his admission of guilt overshadowed the strategy of explanation which he employed to defend himself.  相似文献   

Workshop report     

John Smyth  Ralph G. Straton 《The Australian Educational Researcher》1985,12(3):44-44

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