Interval length and time-use by children with AD/HD: a comparison of four models

Predictions made by 4 competing models of time use by children with AD/HD were tested using a computerized version of the Matching Familiar Figures Test in 2 studies. In Study 1 teacher-identified AD/HD children (N = 10) and non-AD/HD controls (N = 10) completed the task under 3 different trial duration conditions (5, 10, and 15 s). In Study 2 the same task was completed by a group of children with a diagnosis of Hyperkinetic Disorder (N = 12) and controls (N = 12). In both studies AD/HD children performed poorly on trials of both 5- and 15-s duration but as well as controls on the 10-s trials. This quadratic function provided support for the State Regulation Deficit model of time use in AD/HD. The value of tailoring the temporal features of learning contexts to the conceptual style of AD/HD children is discussed.     

Dissimilarity cumulation theory in arc-connected spaces

This paper continues the development of the Dissimilarity Cumulation theory and its main psychological application, Universal Fechnerian Scaling [Dzhafarov, E.N and Colonius, H. (2007). Dissimilarity Cumulation theory and subjective metrics. Journal of Mathematical Psychology, 51, 290-304]. In arc-connected spaces the notion of a chain length (the sum of the dissimilarities between the chain’s successive elements) can be used to define the notion of a path length, as the limit inferior of the lengths of chains converging to the path in some well-defined sense. The class of converging chains is broader than that of converging inscribed chains. Most of the fundamental results of the metric-based path length theory (additivity, lower semicontinuity, etc.) turn out to hold in the general dissimilarity-based path length theory. This shows that the triangle inequality and symmetry are not essential for these results, provided one goes beyond the traditional scheme of approximating paths by inscribed chains. We introduce the notion of a space with intermediate points which generalizes (and specializes to when the dissimilarity is a metric) the notion of a convex space in the sense of Menger. A space is with intermediate points if for any distinct there is a different point such that (where D is dissimilarity). In such spaces the metric G induced by D is intrinsic: coincides with the infimum of lengths of all arcs connecting to In Universal Fechnerian Scaling D stands for either of the two canonical psychometric increments and (ψ denoting discrimination probability). The choice between the two makes no difference for the notions of arc-connectedness, convergence of chains and paths, intermediate points, and other notions of the Dissimilarity Cumulation theory.     

Effects of component length and of the transitions among components in multiple schedules

Pigeons received equal variable-interval reinforcement during presentations of two line-orientation stimuli while five other orientations appeared in extinction. Component duration was 30 seconds for all orientations and the sequence was arranged so that each orientation preceded itself and each other orientation equally often. The duration of one component (0°) was shortened to 10 seconds and the other (90°) was lengthened to 50 seconds. All animals showed large increases in response rate in the shortened component and this increase was recoverable after an interpolated condition in which all components were again 30 seconds in duration. This effect was replicated in a second experiment in which component duration was changed from 150 seconds to 50 seconds and 250 seconds. An examination of local contrast effects during the first experiment showed that the shortened component produced local contrast during subsequent presentations of the lengthened component, just as would a component associated with more frequent reinforcement. When the presentation sequence was changed so that the lengthened component was always followed by the shortened component, response rates generally increased during the lengthened component. When the sequence was arranged so that the shortened component always preceded the longer component, response rate decreased in the former. These effects, as well as the increases in response rate following change in component length, seem not to be the product of local contrast effects among components.     

Reading and lexicalization in opaque and transparent orthographies: Word naming and word learning in English and Spanish

Do skilled readers of opaque and transparent orthographies make differential use of lexical and sublexical processes when converting words from print to sound? Two experiments are reported, which address that question, using effects of letter length on naming latencies as an index of the involvement of sublexical letter–sound conversion. Adult native speakers of English (Experiment 1) and Spanish (Experiment 2) read aloud four- and seven-letter high-frequency words, low-frequency words, and nonwords in their native language. The stimuli were interleaved and presented 10 times in a first testing session and 10 more times in a second session 28 days later. Effects of lexicality were observed in both languages, indicating the deployment of lexical representations in word naming. Naming latencies to both words and nonwords reduced across repetitions on Day 1, with those savings being retained to Day 28. Length effects were, however, greater for Spanish than English word naming. Reaction times to long and short nonwords converged with repeated presentations in both languages, but less in Spanish than in English. The results support the hypothesis that reading in opaque orthographies favours the rapid creation and use of lexical representations, while reading in transparent orthographies makes more use of a combination of lexical and sublexical processing.     

单病种平均住院日影响因素分析

为探讨单病种平均住院日的影响因素,采用多元逐步回归分析,对住院构成前5位病种的平均住院日影响因素进行分析。结果显示,有10个影响因素进入回归方程,不同病种平均住院日影响因素略有不同,是否转科对平均住院日影响最大。在医院管理过程中,需不断加强医院流程管理与改造,实施临床路径,合理制定医院平均住院日指标。