Exploring the set-theoretical structure of objects by additive trees

Arrangements of feature sets that have been proposed to represent qualitative and quantitative variation among objects are shown to generate identical sets of set-symmetric distances. The set-symmetric distances for these feature arrangements can be represented by path lengths in an additive linear tree. Imperfect versions of these feature arrangements are proposed, which also are indistinguishable by the set-symmetric distance model. The distances for the imperfect versions can be represented by path lengths in an additive imperfectly linear tree. When dissimilarities are defined by the more general contrast model and a constant may be added to proximity data, then for both the perfect and imperfect arrangements an additive tree analysis obtains a perfect fit with an imperfectly linear tree. However, in the case of the contrast model also the distinction between the perfect and imperfect arrangements disappears in that also for the perfect arrangements the resulting tree need no longer be linear.The author is grateful to Mathieu Koppen for detailed comments on an earlier version of this article.     

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.     

Changes in Anxiety Control Beliefs Following a Brief CBT Treatment and Their Association With Anxiety Symptom Reduction

Anxiety control beliefs (i.e., beliefs regarding one’s ability to cope with external, fear-inducing threats and internal reactions to those perceived threats) have been found to negatively predict anxiety symptoms in children and adults and to be modifiable by cognitive-behavioral therapy for anxiety disorders. The current study examines whether changes in anxiety control beliefs were seen following a brief, intensive treatment for specific phobias, and whether those changes were associated with improvements in the targeted phobia and comorbid anxiety disorder symptoms. Participants were 135 children and adolescents (M age = 9.01 years, 49% male) who received one-session treatment (OST) with or without parental involvement for their primary specific phobia. Results indicated that self-reported anxiety control beliefs significantly increased following treatment and that these increases significantly predicted reductions in specific phobia severity and symptoms of comorbid anxiety disorders 6 months and 1 year following treatment. Findings illustrate that involvement in a single 3-hour OST was associated with changes in anxiety control beliefs and demonstrate the potential importance of targeting control beliefs in pediatric anxiety treatment.     

Word Order Variation is Partially Constrained by Syntactic Complexity

Previous work suggests that when speakers linearize syntactic structures, they place longer and more complex dependents further away from the head word to which they belong than shorter and simpler dependents, and that they do so with increasing rigidity the longer expressions get, for example, longer objects tend to be placed further away from their verb, and with less variation. Current theories of sentence processing furthermore make competing predictions on whether longer expressions are preferentially placed as early or as late as possible. Here we test these predictions using hierarchical distributional regression models that allow estimates of word order and word order variation at the level of individual dependencies in corpora from 71 languages, while controlling for confounding effects from the type of dependency (e.g., subject vs. object), and the type of clause (main vs. subordinate) involved as well as from trends that are characteristic of individual languages, language families, and language contact areas. Our results show the expected correlations of length with position and variation only for two out of six dependency types (obliques and nominal modifiers) and no difference between clause types. These findings challenge received theories of across-the-board effects of complexity on word order and word order variation and call for theoretical models that relativize effects to specific kinds of syntactic structures and dependencies.     

工作记忆中的词长效应

工作记忆中的词长效应是指在即时序列回忆中短单词列的成绩优于长单词列的现象。该文首先回顾与词长效应有关的实验研究及阐述对应的理论解释,包括经典的语音回路理论和新近提出的特征模型、整合理论、项目位置权衡理论和SIMPLE理论等,然后介绍在这一方面运用脑成像技术研究的进展,如ERP,PET和fMRI方面的研究,为词长效应理论解释提供了进一步的证据,接着讨论词长效应研究中存在的争议,最后简评各主要理论并展望了今后研究的趋势     

年老化对中文阅读眼动控制的影响:来自词长和语境预测性效应的证据

本研究通过对比老年与青年人在阅读中词长、词频和语境预测性效应上的差异,探讨中文阅读中眼动控制的年老化问题。结果发现:(1)词长的年龄主效应显著,注视时间和首次注视位置指标上年龄与词长的交互作用显著;(2)在注视时间指标上发现了显著的词频和语境预测性效应,年龄与语境预测性之间交互作用显著。综合而言,中文阅读中老年读者的词长效应和语境预测性效应不同于青年读者,由此可见,视觉功能和词汇加工功能衰退都是中文阅读眼动控制年老化的诱发原因。     

学前教育年限与母亲受教育水平对农村一年级 小学生学校适应的影响

研究采用同伴提名法、教师和家长报告法,对农村135名一年级小学生进行了为期一年的追踪调查,在此基础上,考察了学前教育年限、母亲受教育水平与学校适应之间的关系。结果表明:(1)学前教育年限越长,小学生越多地表现出积极社会行为,但这种优势仅体现在小学入学初期;(2)母亲受教育水平越低,小学生越多地表现出敏感退缩行为和受拒绝同伴关系;(3)对于母亲受教育水平较低的小学生,学前教育年限越长,其攻击冒犯行为越多;而对于母亲受教育水平较高的小学生,学前教育年限越长,其攻击冒犯行为越少。可见,母亲受教育水平与学前教育年限相互作用,共同影响儿童发展结果,且母亲受教育水平的影响作用更为明显。     

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.     

Within-session delay-of-reinforcement gradients

Within-session delay-of-reinforcement gradients were generated with pigeons by progressively increasing delays to reinforcement within each session. In Experiment 1, the effects of imposing progressive delays on variable-interval and fixed-interval schedules were investigated while controlling for simultaneous decreases in reinforcer rate across the session via a within-subject yoked-control procedure. Rate of key pecking decreased as a negatively decelerated function of delay of reinforcement within a session. These rate decreases were greater than those during a yoked-interval session in which the rate of immediate reinforcement decreased at the same rate as it did under the progressive-delay procedure. In Experiment 2, delay-of-reinforcement gradients were shallower when the progressive delay intervals were signaled by a blackout than when they were unsignaled. The delay gradients obtained in each experiment were similar to those generated under conditions in which different delays of reinforcement are imposed across blocks of sessions. The present procedure offers a technique for rapidly generating delay-of-reinforcement gradients that might serve as baselines for assessing the effects of other behavioral and pharmacological variables.