Experience with malleable objects influences shape-based object individuation by infants

Infants’ ability to accurately represent and later recognize previously viewed objects, and conversely, to discriminate novel objects from those previously seen improves remarkably over the first two years of life. During this time, infants acquire extensive experience viewing and manipulating objects and these experiences influence their physical reasoning. Here we posited that infants’ observations of object feature stability (rigid versus malleable) can influence the use of those features to individuate two successively viewed objects. We showed 8.5-month-olds a series of objects that could or could not change shape, then assessed their use of shape as a basis for object individuation. Infants who explored rigid objects later used shape differences to individuate objects; however, infants who explored malleable objects did not. This outcome suggests that the latter infants did not take into account shape differences during the physical reasoning task and provides further evidence that infants’ attention to object features can be readily modified based on recent experiences.     

Preference for infant-directed speech in preterm infants

The current study explores the effects of exposure to maternal voice on infant sucking in preterm infants. Twenty-four preterm infants averaging 35 weeks gestational age were divided randomly into two groups. A contingency between high-amplitude sucking and presentation of maternal voice was instituted for one group while the other group served as a yoked control. No significant differences were observed in sucking of the two groups, but the degree of pitch modulation of the maternal voice predicted an increase in the rate of infant sucking.     

SAwSu: An Integrated Model of Associative and Reinforcement Learning

Successfully explaining and replicating the complexity and generality of human and animal learning will require the integration of a variety of learning mechanisms. Here, we introduce a computational model which integrates associative learning (AL) and reinforcement learning (RL). We contrast the integrated model with standalone AL and RL models in three simulation studies. First, a synthetic grid‐navigation task is employed to highlight performance advantages for the integrated model in an environment where the reward structure is both diverse and dynamic. The second and third simulations contrast the performances of the three models in behavioral experiments, demonstrating advantages for the integrated model in accounting for behavioral data.     

The “impact factor style of thinking”: A new theoretical framework

Over the last few years, university policy in developed countries has placed too much emphasis on assessing publications on the basis of the impact factor. Any scientific material that has not been published in a journal indexed in the Journal Citation Reports is academically irrelevant. Hence, researchers strive hard to publish in such journals. Failure to achieve this means not having a successful career or receiving any academic recognition. A thorough analysis of the effects of this phenomenon on the researcher community leads to the conclusion that the overestimation of the impact factor is likely to cause disappointment among many researchers. Researchers only have two options: adopting a politically correct behavior, that is, following the “impact factor style of thinking”, or accepting the futility of their research regardless of its relevance. This is an example of the involvement of university policy habitus obsessed impact index. O policy impact index is accepted, or is doomed to academic ostracism, and exclusion from participation in all university policy.     

灵棋课法的由来及其符号解读

本文将灵棋占法当作"易占"的一个支派加以研究.作者以<道藏>本及<四库全书>本中的<灵棋经>为基本文献,考察"灵棋课法"的由来与归属.作者认为,从道书记载情形看,灵棋课法早先应该属于道教使用的一种卜筮技艺.在分析了灵棋课法与易学的关系之后,作者从神明崇拜的角度进一步考察灵棋课法的道教色彩,阐述了该法所蕴含的思想旨趣,发掘其象征底蕴.     

Constrained paths based on the Farey sequence in learning to juggle

In this article we report the results of a study conducted to investigate the learning dynamics of three-ball juggling from the perspective of frequency locking. Based on the Farey sequence, we predicted that four stable coordination patterns, corresponding to dwell ratios of 0.83, 0.75, 0.67, and 0.50, would appear in the learning process. We examined the learning process in terms of task performance, taking into account individual differences in the amount of learning. We observed that the participants acquired individual-specific coordination patterns in a relatively early stage of learning, and that those coordination patterns were preserved in subsequent learning, even though performance in terms of number of successful consecutive throws increased substantially. This increase appeared to be related to a reduction in spatial variability of the juggling movements. Finally, the observed coordination patterns were in agreement with the predicted patterns, with the proviso that the pattern corresponding to a dwell ratio of 0.50 was not realized and only a hint of evidence was found for the dwell ratio of 0.67. This implies that the dwell ratios of 0.83 and 0.75 in particular exhibited a stable coordination structure due to strong frequency locking between the temporal variables of juggling.     

Procedural learning and automatization process in children with developmental coordination disorder and/or developmental dyslexia

ObjectiveThere is increasing evidence to suggest that developmental dyslexia (DD) and developmental coordination disorder (DCD) actually form part of a broader disorder. Their frequent association could be justified by a deficit of the procedural memory system, that subtends many of the cognitive, motor and linguistic abilities that are impaired in both DD and DCD. However, studies of procedural learning in these two disorders have yielded divergent results, and in any case no studies have so far addressed the issue of automatization (dual-task paradigm).MethodsWe administered a finger tapping task to participants aged 8–12 years (19 DCD, 18 DD, and 22 with both DD and DCD) to explore procedural learning and automatic movements in these three groups of children, comparing motor performances at the prelearning stage, after 2 weeks of training, and in a post-training dual-task condition.ResultsFirst, results indicated that all the children were able to learn a sequence of movements and even automatize their movements. Second, they revealed between-groups differences in procedural/automatization learning abilities, setting the DCD group apart from the other two. Third, contrary to our expectations concerning comorbidity, they suggested that the DD + DCD association does not have an additional impact on behavioral performances.     

The impact of concurrent visual feedback on coding of on-line and pre-planned movement sequences

The purpose of this study was to determine the extent to which participants could effectively switch from on-line (OL) to pre-planned (PP) control (or vice versa) depending on previous practice conditions and whether concurrent visual feedback was available during transfer testing. The task was to reproduce a 2000 ms spatial–temporal pattern of a sequence of elbow flexions and extensions. Participants were randomly assigned to one of two practice conditions termed OL or PP. In the OL condition the criterion waveform and the cursor were provided during movement production while this information was withheld during movement production for the PP condition. A retention test and two effector transfer tests were administered to half of the participants in each acquisition conditions under OL conditions and the other half under PP conditions. The mirror effector transfer test required the same pattern of muscle activation and limb joint angles as required during acquisition. The non-mirror transfer test required movements to the same visual–spatial locations as experienced during acquisition. The results indicated that when visual information was available during the transfer tests performers could switch from PP to OL. When visual information was withdrawn, they shifted from the OL to the PP-control mode. This finding suggests that performers adopt a mode of control consistent with the feedback conditions provided during testing.     

Representing time in language and memory: The role of similarity structure

Every day we read about or watch events in the world and can easily understand or remember how long they last. What aspects of an event are retained in memory? And how do we extract temporal information from our memory representations? These issues are central to human cognition, as they underlie a fundamental aspect of our mental life, namely our representation of time. This paper reviews previous language studies and reports a visual learning study indicating that properties of the events encoded in memory shape the representation of their duration. The evidence indicates that for a given event, the extent to which its associated properties or sub-components differ from one another modulates our representation of its duration. These properties include the similarity between sub-events and the similarity between the situational contexts in which an event occurs. We suggest that the diversity of representations that we associate with events in memory plays an important role in remembering and estimating the duration of experienced or described events.