Investigating Behavioral Dynamics With A Fixed-time Extinction Schedule And Linear Analysis

This paper describes the behavioral adaptation observed for 16 pigeons responding to a step transition in the reinforcement rate in a repeated-trial design. Within each trial, following exposure for a fixed period to a variable-interval schedule, there was an unsignaled change in the schedule to extinction. The step transition allowed an experimental test of the applicability of a linear analysis to steady-state dynamic behavior. The computations required for this test yielded, as an intermediate result, transfer functions for each of the 16 birds from 1 mHz to 256 mHz. The transfer functions obtained show greater responsiveness to lower frequencies (i.e., longer time-scale structures in the reinforcement schedule); hence, the pigeons have the characteristics of a low-pass filter. The outcome of the test is that some predictability of the pigeons' future behavior is possible.     

Dynamics of time discrimination: II. The effects of multiple impulses.

According to a diffusion generalization model, time discrimination is determined by the frequency and recency of preceding intervals of time. A procedure for studying rapid timing was used to investigate whether pigeons' wait-time responses were sensitive to these factors. In Experiment 1 the number (two or eight) and spacing (consecutive or far apart) of 5-s interfood intervals (called impulses) intercalated in a series of 15-s interfood intervals (nonimpulses) were studied. Experiment 2 was identical to the first but the interfood intervals were increased by a factor of three. Overall, impulses shortened wait times in the next interfood interval. However, several impulses occurring in succession extended the localized effect of an impulse: Wait times following a set of eight-close impulses were slow to recover to preimpulse levels. The results show that linear waiting is only an approximation to the dynamic process, and a process that is sensitive to events in an animal's remote past, such as the diffusion generalization model, provides a better account of rapid timing effects.     

Psychological distance to reward: Segmentation of aperiodic schedules of reinforcement

College students responded for monetary rewards in two experiments on choice between differentially segmented aperiodic schedules of reinforcement. On a microcomputer, the concurrent chains were simulated as an air-defense video game in which subjects used two radars for detecting and destroying enemy aircraft. To earn more cash-exchangeable points, subjects had to shoot down as many planes as possible within a given period of time. For both experiments, access to one of two radar systems (terminal link) was controlled by a pair of independent concurrent variable-interval 60-s schedules (initial link) with a 4-s changeover delay always in effect. In Experiment 1, the appearance of an enemy aircraft in the terminal link was determined by a variable-interval (15 s or 60 s) schedule or a two-component chained variable-interval schedule of equal duration. Experiment 2 was similar to Experiment 1 except for the segmented schedule, which had three components. Subjects preferred the unsegmented schedule over its segmented counterpart in the conditions with variable-interval 60 s, and preference tended to be more pronounced with more components in the segmented schedule. These findings are compatible with those from previous studies of periodic and aperiodic schedules with pigeons or humans as subjects.     

Pigeons' wait-time responses to transitions in interfood-interval duration: Another look at cyclic schedule performance

Recent developments reveal that animals can rapidly learn about intervals of time. We studied the nature of this fast-acting process in two experiments. In Experiment 1 pigeons were exposed to a modified fixed-time schedule, in which the time between food rewards (interfood interval) changed at an unpredictable point in each session, either decreasing from 15 to 5 s (step-down) or increasing from 15 to 45 s (step-up). The birds were able to track under both conditions by producing postreinforcement wait times proportional to the preceding interfood-interval duration. However, the time course of responding differed: Tracking was apparently more gradual in the step-up condition. Experiment 2 studied the effect of having both kinds of transitions within the same session by exposing pigeons to a repeating (cyclic) sequence of the interfood-interval values used in Experiment 1. Pigeons detected changes in the input sequence of interfood intervals, but only for a few sessions—discrimination worsened with further training. The dynamic effects we observed do not support a linear waiting process of time discrimination, but instead point to a timing mechanism based on the frequency and recency of prior interfood intervals and not the preceding interfood interval alone.     

序列学习是否是内隐学习？

序列学习是继人工语法之后内隐学习的另一研究范式。以往观点认为,在练习后,被试对规则刺激和随机刺激在反应时上出现差异,就表明被试是内隐学习,这种差异量就是内隐学习量。但现在很多学者对序列学习是否内隐这一问题提出了疑问;运用新方法（过程分离法,简称PDP）的研究发现,序列学习是否内隐同反应-刺激间隔（RSI）有关,当RSI = 0时,序列学习才是内隐的;根据RSI提出了神经网络模型。     

认知诊断模型的标准误与置信区间估计：并行自助法

认知诊断模型的标准误(Standard Error, SE; 或方差—协方差矩阵)与置信区间(Confidence Interval, CI)在模型参数估计不确定性的度量、项目功能差异检验、项目水平上的模型比较、Q矩阵检验以及探索属性层级关系等领域有重要的理论与实践价值。本研究提出了两种新的SE和CI计算方法：并行参数化自助法和并行非参数化自助法。模拟研究发现：模型完全正确设定时, 在高质量及中等质量项目条件下, 这两种方法在计算模型参数的SE和CI时均有好的表现; 模型参数存在冗余时, 在高质量及中等质量项目条件下, 对于大部分允许存在的模型参数而言, 其SE和CI有好的表现。通过实证数据展示了新方法的价值及计算效率提升效果。     

Intrinsic goals for leisure-time physical activity predict children's daily step counts through autonomous motivation

ObjectivesThe present study tested a motivational sequence in which children's goals for leisure-time sport and physical activity (PA) from Goal Content Theory predicted pedometer-determined PA through behavioural regulation constructs from Self-Determination Theory.DesignQuantitative cross-sectional study.MethodsA sample of 1272 Flemish (Dutch speaking part of Belgium) sixth graders (M age = 11.42 years) filled in a questionnaire on PA goal content, behavioural regulations and pubertal status. Children's height and weight were measured to assess Body Mass Index (BMI). To measure daily PA behaviour, participants wore a pedometer for seven consecutive days. Structural equation modelling was performed to test the proposed motivational sequence and to examine the mediation effect of behavioural regulations towards leisure-time sport and PA on the relation between PA goal content and daily step counts.ResultsA structural equation model supported the hypothesized sequence in which intrinsic goals for leisure-time sport and PA predicted children's daily step counts through autonomous motivation towards leisure-time sport and PA. Multi-sample invariance testing revealed that the proposed model was largely invariant across BMI groups, pubertal status and gender.ConclusionsThe findings highlight the importance of emphasizing intrinsic goals for participation in leisure-time sport and PA in children aged 10–12 years. By stimulating children to participate in PA and sports by referring to intrinsic goals, children are more likely to enjoy PA, which in turn might increase the likelihood of a regular and long-term PA engagement.     

Does temporal contiguity moderate contingency learning in a speeded performance task?

In four experiments, we varied the time between the onset of distracting nonwords and target colour words in a word–word version of the colour–word contingency learning paradigm. Contingencies were created by pairing a distractor nonword more often with one target colour word than with other colour words. A contingency effect corresponds to faster responses to the target colour word on high-contingency trials (i.e., distractor nonword followed by the target colour word with which it appears most often) than on low-contingency trials (i.e., distractor nonword followed by a target colour word with which it appears only occasionally). Roughly equivalent-sized contingency effects were found at stimulus-onset asynchronies (SOAs) of 50, 250, and 450 ms in Experiment 1, and 50, 500, and 1,000 ms in Experiment 2. In Experiment 3, a contingency effect was observed at SOAs of –50, –200, and –350 ms. In Experiment 4, interstimulus interval (ISI) was varied along with SOA, and learning was equivalent for 200-, 700-, and 1,200-ms SOAs. Together, these experiments suggest that the distracting stimulus does not need to be presented in close temporal contiguity with the response to induce learning. Relations to past research on causal judgement and implications for further contingency learning research are discussed.