Reversibility of single-incentive selective associations.

Rats were trained to press a lever in the presence of a tone-light compound stimulus and not to press in its absence. In each of two experiments, schedules were designed to make the compound a conditioned punisher for one group and a conditioned reinforcer for the other. In Experiment 1, one group's responding produced food in the presence of the compound but not in its absence. The other group's responding terminated the compound stimulus, and food was presented only in its absence. When tone and light were later presented separately, light controlled more responding than did tone in the former group, but tone gained substantial control in the latter. The same effects were also observed within subjects when the training schedules were switched over groups. In Experiment 2, two groups avoided shock in the presence of the compound stimulus. In the absence of the compound, one group was not shocked, and the other received both response-independent and response-produced shock. When tone and light were presented separately, the former group's responding was mainly controlled by tone, but the latter group's responding was almost exclusively controlled by light. These effects were also observed within subjects when the training schedules were switched over groups. Thus, these single-incentive selective association effects (appetitive in Experiment 1 and aversive in Experiment 2) were completely reversible. The schedules in which the compound should have been a conditioned reinforcer consistently produced visual control, and auditory control increased when the compound should have become a conditioned punisher. Currently accepted accounts of selective associations based on affinities between shock and auditory stimuli and between food and visual stimuli (i.e., stimulus-reinforcer interactions) do not adequately address these results. The contingencies of reinforcement most recently associated with the compound and with its absence, rather than the nature of the reinforcer, determined whether auditory or visual stimulus control developed.     

System and flexibility in law

Usually, rhetoric is supposed to provide a model of law which describes legal interactions as volitive, arbitrary, and void of any system. However, the Mainz School, founded by Theodor Viehweg, proves the contrary: without referring to any metaphysics, such as consensus or auditoire universel, it seeks to discover the systematic character and the more or less flexible structures of legal rhetoric.     

应用动态因果模型研究阅读神经网络背、腹侧通路的协作机制

在神经网络的最新取向下, 探讨阅读脑机制中背侧和腹侧通路的协作机制, 是解决语言认知神经科学多个理论问题共同面临的焦点。本项目拟通过两个脑功能成像实验, 建构汉字阅读的动态因果模型, 系统地考察汉字阅读的神经网络, 以及阅读网络中背、腹侧通路的协作机制。实验一利用快速适应实验范式的优点, 识别和考察汉字阅读涉及的认知成分所对应的功能脑区, 以及脑区联结形成的神经回路, 并建构汉字阅读的动态因果模型; 实验二进一步考察在刺激属性(语音和语义信息)和任务要求下阅读脑区的动态激活及相互作用。通过不同任务下的模型对比, 重点探讨阅读网络的脑区联结模式变化, 尤其是背、腹侧通路受刺激和任务影响时的协作机制。研究结果将为揭示阅读的神经生理模型、解决语言特异性脑区激活的争论等理论问题提供直接的证据, 还能为语言教学、阅读障碍矫治、以及临床应用提供理论基础与指导。     

认知诊断CAT中具有非统计约束选题方法的比较

项目曝光控制和内容约束关系到测验安全、测验的信度和效度, 是计算机化自适应测验(Computerized Adaptive Testing, CAT)中两类重要的非统计约束条件。本文在认知诊断CAT中针对内容约束和项目曝光控制要求, 运用5种方法选择测验项目。它们分别是：(1) Monte Carlo方法与项目合格方法相结合, 记为MC-IE; (2) Monte Carlo方法与最大优先指标方法相结合, 记为MC-MPI; (3) Monte Carlo方法与限制阈值方法相结合, 记为MC-RT; (4) Monte Carlo方法与限制进度指标方法相结合, 记为MC-RPG以及(5) Monte Carlo方法与最大后验概率方法相结合, 记为MC-PP。然后通过在线性、收敛、发散、无结构和独立五种属性结构下构建题库并运用重参化融融统和模型模拟被试反应比较它们的选题表现。研究发现, (1) 相同选题方法在不同属性结构下项目曝光率的分布类似, 测量精度按线性、收敛、发散、无结构和独立结构的顺序依次降低; (2) 相同属性结构下, 不同方法的测量精度高低依次为MC-PP、MC-IE、MC-RT、MC-MPI和MC-RPG方法; 项目曝光均匀性优劣依次为MC-RPG、MC-MPI、MC-RT、MC-IE和MC-PP方法。统一量纲值表明, MC-RPG方法的综合表现最好, MC-MPI方法的表现次之。     

Dynamic analysis of multivariate panel data with non-linear transformations

Many models for multivariate data analysis can be seen as special cases of the linear dynamic or state space model. Contrary to the classical approach to linear dynamic systems analysis, in which high-dimensional exact solutions are sought, the model presented here is developed from a social science framework where low-dimensional approximate solutions are preferred. Borrowing concepts from the theory on mixture distributions, the linear dynamic model can be viewed as a multi-layered regression model, in which the output variables are imprecise manifestations of an unobserved continuous process. An additional layer of mixing makes it possible to incorporate non-normal as well as ordinal variables.Using the EM-algorithm, we find estimates of the unknown model parameters, simultaneously providing stability estimates. The model is very general and cannot be well estimated by other estimation methods. We illustrate the applicability of the obtained procedure through an example with generated data.     

Soft constraints in interactive behavior: the case of ignoring perfect knowledge in-the-world for imperfect knowledge in-the-head

Constraints and dependencies among the elements of embodied cognition form patterns or microstrategies of interactive behavior. Hard constraints determine which microstrategies are possible. Soft constraints determine which of the possible microstrategies are most likely to be selected. When selection is non-deliberate or automatic the least effort microstrategy is chosen. In calculating the effort required to execute a microstrategy each of the three types of operations, memory retrieval, perception, and action, are given equal weight; that is, perceptual-motor activity does not have a privileged status with respect to memory. Soft constraints can work contrary to the designer’s intentions by making the access of perfect knowledge in-the-world more effortful than the access of imperfect knowledge in-the-head. These implications of soft constraints are tested in two experiments. In experiment 1 we varied the perceptual-motor effort of accessing knowledge in-the-world as well as the effort of retrieving items from memory. In experiment 2 we replicated one of the experiment 1 conditions to collect eye movement data. The results suggest that milliseconds matter. Soft constraints lead to a reliance on knowledge in-the-head even when the absolute difference in perceptual-motor versus memory retrieval effort is small, and even when relying on memory leads to a higher error rate and lower performance. We discuss the implications of soft constraints for routine interactive behavior, accounts of embodied cognition, and tool and interface design.     

A multi-attribute extension of the secretary problem: Theory and experiments

We present a generalization of a class of sequential search problems with ordinal ranks, referred to as “secretary” problems, in which applicants are characterized by multiple attributes. We then present a procedure for numerically computing the optimal search policy and test it in two experiments with incentive-compatible payoffs. With payoffs dependent on the absolute ranks of the attributes, we test the optimal search model with both symmetric (Experiment 1) and asymmetric (Experiment 2) search problems. In both experiments we find that, relative to the optimal search policy, subjects stop the search too early. Our results show that this bias is largely driven by a propensity to stop prematurely on applicants of intermediate (relative) quality.     

Tubes,tables and traps: great apes solve two functionally equivalent trap tasks but show no evidence of transfer across tasks

Previous studies on tool using have shown that presenting subjects with certain modifications in the experimental setup can substantially improve their performance. However, procedural modifications (e.g. trap table task) may not only remove task constraints but also simplify the problem conceptually. The goal of this study was to design a variation of the trap-table that was functionally equivalent to the trap-tube task. In this new task, the subjects had to decide where to insert the tool and in which direction the reward should be pushed. We also administered a trap-tube task that allowed animals to push or rake the reward with the tool to compare the subjects' performance on both tasks. We used a larger sample of subjects than in previous studies and from all the four species of great apes (Gorilla gorilla, Pan troglodytes, Pan paniscus, and Pongo pygmaeus). The results showed that apes performed better in the trap-platform task than in the trap-tube task. Subjects solved the tube task faster than in previous studies and they also preferred to rake in rather than to push the reward out. There was no correlation in the level of performance between both tasks, and no indication of interspecies differences. These data are consistent with the idea that apes may possess some specific causal knowledge of traps but may lack the ability to establish analogical relations between functional equivalent tasks.     

Trust,risk, and the social contract

The problem of trust is discussed in terms of David Hume’s meadow-draining example. This is analyzed in terms of rational choice, evolutionary game theory and a dynamic model of social network formation. The kind of explanation that postulates an innate predisposition to trust is seen to be unnecessary when social network dynamics is taken into account.