The interaction of temporal generalization gradients predicts the context effect

In a temporal double bisection task, animals learn two discriminations. In the presence of Red and Green keys, responses to Red are reinforced after 1-s samples and responses to Green are reinforced after 4-s samples; in the presence of Blue and Yellow keys, responses to Blue are reinforced after 4-s samples and responses to Yellow are reinforced after 16-s samples. Subsequently, given a choice between Green and Blue, the probability of choosing Green increases with the sample duration-the context effect. In the present study we asked whether this effect could be predicted from the stimulus generalization gradients induced by the two basic discriminations. Six pigeons learned to peck Green following 4-s samples (S(+)) but not following 1-s samples (S(-)) and to peck Red following 4-s samples (S(+)) but not following 16-s samples (S(-)). Temporal generalization gradients for Green and Red were then obtained. Finally, the pigeons were given a choice between Green and Red following sample durations ranging from 1 to 16 s. Results showed that a) the two generalization gradients had the minimum at the S(-) duration, an intermediate value between the S(-) and the S(+) durations, and the maximum at the S(+) as well as more extreme durations; b) on choice trials, preference for Green over Red increased with sample duration, the context effect; and c) the two generalization gradients predicted the average context effect well. The Learning-to-Time model accounts for the major trends in the data.     

Deontic and epistemic reasoning in children

It is widely accepted that adults show an advantage for deontic over epistemic reasoning. Two published studies (Cummins, 1996b; Harris and Núñez, 1996, Experiment 4) found evidence of this “deontic advantage” in preschool-aged children and are frequently cited as evidence that preschoolers show the same deontic advantage as adults. However, neither study has been replicated, and it is not clear from either study that preschoolers were showing the deontic advantage under the same conditions as adults. The current research investigated these issues. Experiment 1 attempted to replicate both Cummins’s and Harris and Núñez’s studies with 3- and 4-year-olds (N = 56), replicating the former with 4-year-olds and the latter with both 3- and 4-year-olds. Experiment 2 modified Cummins’s task to remove the contextual differences between conditions, making it more similar to adult tasks, finding that 4-year-olds (n = 16) show no evidence of the deontic advantage when no authority figure is present in the deontic condition, whereas both 7-year-olds (n = 16) and adults (n = 28) do. Experiment 3 removed the authority figure from the deontic condition in Harris and Núñez’s task, again finding that 3- and 4-year-olds (N = 28) show no evidence of the deontic advantage under these conditions. These results suggest that for preschoolers, the deontic advantage is reliant on particular contextual cues such as the presence of an authority figure, in the deontic condition. By 7 years of age, however, children are reasoning like adults and show evidence of the advantage when no such contextual cues are present.     

Musicians and tone-language speakers share enhanced brainstem encoding but not perceptual benefits for musical pitch

Behavioral and neurophysiological transfer effects from music experience to language processing are well-established but it is currently unclear whether or not linguistic expertise (e.g., speaking a tone language) benefits music-related processing and its perception. Here, we compare brainstem responses of English-speaking musicians/non-musicians and native speakers of Mandarin Chinese elicited by tuned and detuned musical chords, to determine if enhancements in subcortical processing translate to improvements in the perceptual discrimination of musical pitch. Relative to non-musicians, both musicians and Chinese had stronger brainstem representation of the defining pitches of musical sequences. In contrast, two behavioral pitch discrimination tasks revealed that neither Chinese nor non-musicians were able to discriminate subtle changes in musical pitch with the same accuracy as musicians. Pooled across all listeners, brainstem magnitudes predicted behavioral pitch discrimination performance but considering each group individually, only musicians showed connections between neural and behavioral measures. No brain-behavior correlations were found for tone language speakers or non-musicians. These findings point to a dissociation between subcortical neurophysiological processing and behavioral measures of pitch perception in Chinese listeners. We infer that sensory-level enhancement of musical pitch information yields cognitive-level perceptual benefits only when that information is behaviorally relevant to the listener.     

歧视知觉对初中生的合作倾向与行为的影响

本文通过两个研究揭示歧视知觉对初中生合作倾向与行为的影响, 研究1采用问卷法对752名初中生进行为期一年的追踪, 运用潜变量交叉滞后结构方程模型分析歧视知觉与合作倾向之间的纵向预测关系; 研究2采用动态公共物品困境实验考察歧视知觉对合作行为的影响, 以及群体类型的调节作用。结果发现：(1)初中生的歧视知觉与合作倾向存在显著负相关; T1合作倾向可负向预测T2歧视知觉, T2歧视知觉可负向预测T3合作倾向; (2)在公共物品困境前三轮投资比和贡献率上, 歧视知觉和群体类型的交互效应显著; 而在后三轮仅发现歧视知觉在投资比和贡献率上的主效应, 以及群体类型在贡献率上的主效应。以上结果表明, 歧视知觉与合作倾向之间存在纵向螺旋式影响; 歧视知觉对前期合作行为的影响受到群体类型的调节, 但随着互动时间延长, 该调节作用消失。     

Distributional learning has immediate and long-lasting effects

Evidence of distributional learning, a statistical learning mechanism centered on relative frequency of exposure to different tokens, has mainly come from short-term learning and therefore does not ostensibly address the development of important learning processes. The present longitudinal study examines both short- and long-term effects of distributional learning of phonetic categories on non-native sound discrimination over a 12-month period. Two groups of listeners were exposed to a two-minute distribution of auditory stimuli in which the most frequently presented tokens either approximated or exaggerated the natural production of the speech sounds, whereas a control group listened to a piece of classical music for the same length of time. Discrimination by listeners in the two distribution groups improved immediately after the short exposure, replicating previous results. Crucially, this improvement was maintained after six and 12 months, demonstrating that distributional learning has long-lasting effects.     

Predictable Mispredictions in the Context of Physical Activity and Sport: A Review

Theoretical models and research that aim to identify antecedents of participation in physical activities or sport can measure antecedents of physical activity behaviour through instruments that involve subjective predictions. In this article, we argue that such instruments may not reflect physical activity experiences or behaviour accurately because people are not very good predictors of future states. Additionally, we propose that mispredictions may be predictable because they are “caused” by tendencies to neglect processes related to hedonic adaptation and competing alternatives. We also suggest that it may be possible to improve measurement of antecedents through methods that focus respondents' attention on factors that cause mispredictions or through experiential sampling methods.