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671.
672.
Rats were given a footshock followed by ECS of either low or high intensity. Controls received neither footshock nor ECS. Twenty-four hours later all subjects acquired a simple position habit in a water maze. Then, independent subgroups were reversal trained at 24-hr intervals up to 144 hr post-treatment. Compared to controls, rats given footshock, and ECS showed memory for training at the initial test followed by amnesia, memory recovery, and finally amnesia at subsequent tests. The alternating pattern of retention appeared to be a function of ECS intensity. In a second experiment, rats were first maze trained then given footshock and ECS 24 hr later. Like the results of the first experiment, ensuing tests indicated an alternating retention function in experimental animals again influenced by ECS intensity. Several possible explanations of these results were discussed, and it was suggested that the altering retention function observed in the experimental animals resulted from a footshock and ECS induced state dependency effect that subsided and recurred spontaneously up to 144 hr post-treatment. 相似文献
673.
The use of well-documented procedures such as shaping, differential reinforcement, and fading may not be the most practical for teaching certain academic behaviors. An alternative procedure of interspersing trials on previously trained items with trials on unknown items has been suggested, but its effects on acquisition and retention have not been systematically examined. This study investigated the effects of interspersing known items during training on new tasks. Six mentally retarded adolescents were given pretests on spelling and sightreading words, which were divided into pools of learned and unlearned items. Training and baseline conditions were implemented concurrently, using a multi-element design. During interspersal training sessions, 10 known words from the pretest were alternately presented with each of 10 test words that were incorrect on the pretest. The ratio of previously mastered words to test words was gradually reduced. During baseline sessions, 10 different test words were presented without alternation of previously known words. During this condition, a procedure involving high-density social reinforcement contingent on task-related behaviors, but not necessarily correct responses, was later introduced, followed by a return to the original noninterspersal baseline. During all conditions, test words were deleted and replaced after meeting a mastery criterion of three consecutive correct trials. Retention tests were administered over learned test words for all conditions, at specified intervals. Results showed that both acquisition and retention of spelling and sightreading words were facilitated by the interspersal procedure. All subjects acquired more words during the interspersal condition than either the high-density or baseline conditions. The effectiveness of the procedure may possibly be attributed to better maintenance of attending behavior to unknown items as a function of the inclusion of known items, which directly increase the amount of reinforcement for correct responses during the early stages of skill acquisition. 相似文献
674.
Patterns of visual selection were recorded as Ss viewed pairs of stimulus drawings in which the two members were either both incongruous or both banal. Prior to presenting the paired stimuli, S was preexposed to either one member of the stimulus pair or to the incongruous or banal counterpart of one member of the stimulus pair. The results indicate that: (1) preexposure to a stimulus reduced its potential to elicit looking responses, and the magnitude of that reduction was greater for incongruous stimuli than for banal stimuli; (2) preexposure to an incongruous stimulus affected the potential of its banal counterpart to elicit looking responses, but preexposure to a banal stimulus did not affect the potential of its incongruous counterpart to elicit similar responses; and (3) the reduced potential of the preexposed member of a stimulus pair to elicit looking responses waned after 10 sec. These results were discussed in light of an “information-conflict resolution” model of visual selection. 相似文献
675.
Recent research on nicotine self-administration has highlighted the need to accurately assess within-cigarette topography in order to estimate changes in puff profiles that occur in response to varying nicotine content. This paper describes equipment and techniques that may be used to record puff volume in the laboratory and discusses methods used by other researchers to study puff volume with an emphasis on methodological advantages of the present technique. 相似文献
676.
Data from a longitudinal study of postbaccalaureate nursing careers are discussed in the context of the motive-to-avoid-success controversy. Two groups of nurses with continuous work histories were intensively studied. While most had experienced upward professional mobility, a significant minority had lateral careers, which, though not characterized by advancement, typically provide rewards of intensification. Further, lateral careers only occurred in specialties allowing a high degree of professional autonomy. Thus, upward mobility and advancement should not be the sole criteria of women's occupational progress. Alternative conceptions of success may be significant in many occupations, although such beliefs may not serve as viable substitutes for professional autonomy and the opportunity for personal development. Lateral movement may also characterize most men's work lives more aptly than descent or ascent; hence the findings underscore the necessity to rethink the image of movement in both male and female work spheres.The research upon which this paper is based was supported by a grant from the Nursing Resources Division, USPHS (Grant NU-004-94-03) for the study of Post-Baccalaureate Careers in Nursing, Fred Davis and Virginia Olesen, Principal Investigators, Ellen Lewin, Assistant Project Director. This article was originally presented as a paper at the Pacific Sociological Association meetings, Sacramento, California, April 1977, where the panel commentator, Sheryl Ruzek, provided useful comments on the essay. Jane Tabata Usami provided a very helpful bibliographic search and other technical assistance. 相似文献
677.
Forty bilinguals from several language backgrounds were contrasted to a group of English-speaking monolinguals on a verbal-manual interference paradigm. For the monolinguals, concurrent finger-tapping rate during speech output tasks was disrupted only for the right hand, indicating left-hemisphere language dominance. Bilingual laterality patterns were a function of language used: native (L1) versus second acquired (L2), and age of L2 acquisition. Early bilinguals (L1 + L2 acquisition prior to age 6) revealed left-hemisphere dominance for both languages, whereas late bilinguals (L2 acquired beyond age 6) revealed left-hemisphere dominance only for L1 and symmetrical hemispheric involvement for L2. 相似文献
678.
Terry Caelli 《Attention, perception & psychophysics》1982,31(2):149-159
Recent developments in modeling image discrimination by feature analytic and frequency selective methods are discussed. Some issues relating to the design of two-dimensional spatial frequency filters are developed within the context of two experiments on texture discrimination using artificial and naturally occurring textures. Results of these experiments indicate that, given an adequately formulated relationship between spatial frequency and orientation tuning parameters of the filter, one can predict a variety of texture discriminations using only amplitude-specific models. Finally, guidelines are established for ascertaining when phase transmission characteristics do become critical in two-dimensional image processing by the human observer. 相似文献
679.
680.