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51.
Identification of distinct units within a continuous flow of human action is fundamental to action processing. Such segmentation
may rest in part on statistical learning. In a series of four experiments, we examined what types of statistics people can
use to segment a continuous stream involving many brief, goal-directed action elements. The results of Experiment 1 showed no evidence for sensitivity to conditional probability, whereas Experiment 2 displayed learning based on joint probability. In Experiment 3, we demonstrated that additional exposure to the input failed to engender sensitivity to conditional probability. However,
the results of Experiment 4 showed that a subset of adults—namely, those more successful at identifying actions that had been seen more frequently than
comparison sequences—were also successful at learning conditional-probability statistics. These experiments help to clarify the mechanisms subserving processing
of intentional action, and they highlight important differences from, as well as similarities to, prior studies of statistical
learning in other domains, including language. 相似文献
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Yangxueqingnao particles inhibit rat vascular smooth muscle cell proliferation induced by lysophosphatidic acid 总被引:1,自引:0,他引:1
Cai W Xu Y Chen JZ Huang SR Lu ZY Wang ZK 《Journal of Zhejiang University. Science. B》2005,6(9):892-896
Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) proliferation induced by lysophosphatidic acid (LPA). Methods: The amount of3H-TdR (3H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation end product malondialdehyde (MDA)content of the VSMC were assayed. Results: 1×10-9, 1×10-8, 1×10-7 mol/L LPA in a concentration dependent manner, induced the amount of 3H-TdR admixed, MAP kinase activity, and MDA content of the cultured rat VSMC to increase. However, 5%, 10%,and 15% Yangxueqingnao serum preincubation resulted in a decrease of 23.0%, 42.0%, and 52.0% (P<0.01) respectively in the amount of 3H-TdR admixed, a decline in VSMC MAP kinase activity of 13.9% (P<0.05), 29.6% (P<0.01), and 48.9% (P<0.01)respectively, and also, a decrease in MDA content of VSMC of 19.4%, 24.7%, and 43.2% (P<0.01) respectively, in the 1×10-7mol/L LPA-treated VSMC. Conclusions: LPA activates the proliferation and lipid peroxidation of VSMC in a concentration dependent manner. The LPA-induced VSMC proliferation is related to the activity of MAP kinases, enzymes involved in an intracellular signalling pathway. The results of the present study showed that Yangxueqingnao particles can effectively inhibit LPA-induced VSMC proliferation, MAP kinase activation, and reduce lipid peroxidative lesion. 相似文献
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Diversity of Gram negative bacteria antagonistic against major pathogens of rice from rice seed in the tropic environment 总被引:2,自引:0,他引:2
INTRODUCTIONRiceseedharborsadozenofplantpathogen icbacteria (Gotoetal.,1 988;Xieetal.,1 998) .Thebacterialpathogenscausearangeofricediseases,someverydestructivewhileothershavenoeffectonricecropgrowth .Inthisstudy ,wefoundalargenumberofbacteriaasso ciatedw… 相似文献
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To obtain confirmation of the findings of the authors' earlier comparison of ever-pregnant and nonpregnant Black high school students from Tennessee, 16 students confirmed to be pregnant were substituted for the 33 subjects in the original study whose pregnancy status was based solely on self-report. The nonpregnant control group of 251 teens was utilized in both analyses. Although the confirmed pregnant group was too small to repeat the regression analysis, striking concordance of findings between the 2 studies emerged for all dependent variables except the Eysenck Personality Questionnaire anxiety scale. The lower anxiety scores recorded among subjects in the original study may be either a statistical artifact or a reflection of the fact that these pregnant teens remained in school while subjects in the second study were enrolled in programs centered around their pregnant status. Sexual activity scores were strong or moderate significantly more often in both groups of pregnant teens compared to their nonpregnant counterparts. Interesting was the finding that 81% of pregnant teens regarded romance novels and soap operas to be accurate portrayals of real-life dating relationships compared to only 49% of nonpregnant teens. On the other hand, only 56% of the pregnant subjects regarded their own relationships to have this romantic quality. In a future study, the role of such uncritical romantic ideals in adolescent pregnancy risk will be investigated in a larger sample. 相似文献
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Burnham D Leigh G Noble W Jones C Tyler M Grebennikov L Varley A 《Journal of deaf studies and deaf education》2008,13(3):391-404
Caption rate and text reduction are factors that appear to affect the comprehension of captions by people who are deaf or hard of hearing. These 2 factors are confounded in everyday captioning; rate (in words per minute) is slowed by text reduction. In this study, caption rate and text reduction were manipulated independently in 2 experiments to assess any differential effects and possible benefits for comprehension by deaf and hard-of-hearing adults. Volunteers for the study included adults with a range of reading levels, self-reported hearing status, and different communication and language preferences. Results indicate that caption rate (at 130, 180, 230 words per minute) and text reduction (at 84%, 92%, and 100% original text) have different effects for different adult users, depending on hearing status, age, and reading level. In particular, reading level emerges as a dominant factor: more proficient readers show better comprehension than poor readers and are better able to benefit from caption rate and, to some extent, text reduction modifications. 相似文献
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我向空中射出一枝箭,我不知它落在何方。因为它飞得如此神速,我的视力都追赶不上。我向高空唱出一支歌,我不知它落在何方。谁有如此犀利眼力,能追赶上歌声的飞扬? 相似文献