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864.
Statistical consistency and hypothesis testing for nonmetric multidimensional scaling 总被引:1,自引:0,他引:1
Henry E. Brady 《Psychometrika》1985,50(4):509-537
The properties of nonmetric multidimensional scaling (NMDS) are explored by specifying statistical models, proving statistical consistency, and developing hypothesis testing procedures. Statistical models with errors in the dependent and independent variables are described for quantitative and qualitative data. For these models, statistical consistency often depends crucially upon how error enters the model and how data are collected and summarized (e.g., by means, medians, or rank statistics). A maximum likelihood estimator for NMDS is developed, and its relationship to the standard Shepard-Kruskal estimation method is described. This maximum likelihood framework is used to develop a method for testing the overall fit of the model. 相似文献
865.
Symmetry and transitivity of conditional relations in monkeys (Cebus apella) and pigeons (Columba livia) 总被引:10,自引:10,他引:0
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D'Amato MR Salmon DP Loukas E Tomie A 《Journal of the experimental analysis of behavior》1985,44(1):35-47
In Experiment 1 six monkeys were tested with discriminative relations that were backward relative to their training in a 0-second conditional (“symbolic”) matching procedure. Although there was some indication of backward associations, the evidence was generally weak, and statistical evaluations did not reach conventional significance levels. Unlike children, who show backward associations to the point of symmetry, monkeys and pigeons display at best only weak and transient backward associations. In Experiment 2 associative transitivity was assessed across two sets of conditional matching tasks. All four monkeys tested demonstrated strong transitivity. In contrast, in Experiment 3 there was no evidence of transitivity in three pigeons tested under conditions closely comparable to those of Experiment 2. These results may identify some key features of interspecies differences and contribute to analyses of serial learning in animals. 相似文献
866.
Flicker fusion frequencies of 48 healthy controls and of 35 alcoholics were measured to detect possible associations between flicker fusion and signs of nonspecific brain damage, the aim of the study. FFF was statistically significantly lower in patients addicted to alcohol than in healthy subjects. Lower flicker fusion frequencies were associated with the severeness of organic psychosis as rated psychopathologically. The hypothesis that addiction to alcohol is a sign of diffuse, nonspecific, organic brain damage was discussed. 相似文献
867.
E R Delay 《Perceptual and motor skills》1985,60(2):479-483
Locomotor activity of male, albino rats (25, 90, and 200 days old at the start of the experiment) was measured in conditions of light and dark. Continuous and pulsed noises of 50, 60, 70, 80 and 90 dB were presented under each illumination condition. While noise intensity altered activity of all age groups, it interacted with illumination and age, resulting in different sensory-dependent patterns of activity in each age group. The results are interpreted in terms of arousal theory and potential functional development of CNS structures regulating the effects of ambient sensory input on behavior. 相似文献
868.
On the basis of surveys completed by 105 male participants in a popular marathon, a multiple regression analysis was conducted to identify the variables contributing significantly to the prediction of final time. Overall prediction was successful, with R = .896, and training pace was the most important factor in the equation, speedier workouts being associated with faster marathon times. Final time was also related positively to best 10-km race time in the previous 12 mo. and repression-sensitization (faster runners being more sensitized), and negatively to maximum number of training miles in a single week, number of previous marathons completed, and number of days of training lost through illness or injury. Contrary to expectations, locus of control was not related to final time. Only 27% of the runners had lost training time through injury, but a discriminant analysis showed that, compared to those who had avoided this problem, the injured were younger, rested less, ran less in the week prior to the marathon, ran a slightly longer long run but ran it earlier before the race, and ran fewer runs of 20 miles or more. It is suggested that researchers should study the repression-sensitization variable and investigate injury in runners preparing for a marathon. 相似文献
869.
R M Olig R D Staton W W Beatty H Wilson R I Biberdorf S G Hoag R A Brumback 《Perceptual and motor skills》1985,60(3):879-889
Plasma concentrations of imipramine and amitriptyline and their desmethylated metabolites were measured in 20 children being treated for major depressive illness 2 wk. and 5 to 10 wk. after achieving drug dosages of 2.25 mg/kg body weight. At 2 wk. all children had exhibited clinical improvement, but by 10 wk. 4 of the 10 children treated with imipramine and 5 of the 10 children treated with amitriptyline had experienced clinical relapse of depressive symptoms. Tricyclic antidepressant plasma concentrations and ratios were comparable in the subgroups of children who maintained their clinical improvement and those who relapsed. There was no evidence of a systematic decline in plasma tricyclic antidepressant concentrations in those children who relapsed. 相似文献
870.
Behavioral analysis of sexual dysfunction in Hansen's disease 总被引:1,自引:0,他引:1
M E Faulstich 《Perceptual and motor skills》1985,60(1):115-118
Human sexual behavior is an interactive process including CNS, hormonal, and sex-gland activities. This process can be disrupted in males who have Hansen's disease if testicular atrophy occurs. Elevations of centrally mediated luteinizing hormone and deficient testosterone levels were found in a male with Hansen's disease whose insufficient erections were secondary to atrophic testes. Quasi-experimental (A-B) analysis provided evidence for the efficacy of testosterone treatment for such a condition. 相似文献