The inferential interference effects of environmental sounds on spoken speech in Japanese and British people

Spoken speech was paired with several kinds of environmental sounds and presented dichotically to both native Japanese and British subjects to compare the direction and degree of ear advantage. Results suggest that environmental sounds interfere in a similar manner for both groups of subjects but that there are highly significant differences in the degree of ear advantage between the Japanese and British subjects which might be due to some linguistic influences.     

Reversal Learning in Conditional Discriminations Is Not Controlled by Reinforcer Density

The Psychological Record - Three experiments have examined whether a whole-partial reversal effect is due to shift in reinforcement density across phases, between whole and partial reversal in both...     

The gestural repertoire of the wild bonobo (<Emphasis Type="Italic">Pan paniscus</Emphasis>): a mutually understood communication system

In animal communication, signallers and recipients are typically different: each signal is given by one subset of individuals (members of the same age, sex, or social rank) and directed towards another. However, there is scope for signaller–recipient interchangeability in systems where most signals are potentially relevant to all age–sex groups, such as great ape gestural communication. In this study of wild bonobos (Pan paniscus), we aimed to discover whether their gestural communication is indeed a mutually understood communicative repertoire, in which all individuals can act as both signallers and recipients. While past studies have only examined the expressed repertoire, the set of gesture types that a signaller deploys, we also examined the understood repertoire, the set of gestures to which a recipient reacts in a way that satisfies the signaller. We found that most of the gestural repertoire was both expressed and understood by all age and sex groups, with few exceptions, suggesting that during their lifetimes all individuals may use and understand all gesture types. Indeed, as the number of overall gesture instances increased, so did the proportion of individuals estimated to both express and understand a gesture type. We compared the community repertoire of bonobos to that of chimpanzees, finding an 88 % overlap. Observed differences are consistent with sampling effects generated by the species’ different social systems, and it is thus possible that the repertoire of gesture types available to Pan is determined biologically.     

Culture, emotion regulation, and adjustment

This article reports differences across 23 countries on 2 processes of emotion regulation--reappraisal and suppression. Cultural dimensions were correlated with country means on both and the relationship between them. Cultures that emphasized the maintenance of social order--that is, those that were long-term oriented and valued embeddedness and hierarchy--tended to have higher scores on suppression, and reappraisal and suppression tended to be positively correlated. In contrast, cultures that minimized the maintenance of social order and valued individual Affective Autonomy and Egalitarianism tended to have lower scores on Suppression, and Reappraisal and Suppression tended to be negatively correlated. Moreover, country-level emotion regulation was significantly correlated with country-level indices of both positive and negative adjustment.     

Do pointing gestures by infants provoke comments from adults?

In the field of developmental psychology, there is speculation that pointing gestures by infants are good precursors of infant language acquisition, and some researchers have found correlations between these pointing gestures and some indices of language acquisition. Infants’ pointing gestures are presumably related to language acquisition because they provoke verbal responses from adults. To test this, seven boys and six girls were observed during free play time in a nursery classroom, and post-pointing and matched-control data were collected. Comparison between these data confirmed that the nursery staff spoke to infants at a significantly earlier stage in post-pointing sequences, compared with control sequences, indicating that pointing gestures elicit verbal responses from adult caregivers.     

Computational models of inductive reasoning using a statistical analysis of a Japanese corpus

Existing computational models of human inductive reasoning have been constructed based on psychological evaluations concerning the similarities or relationships between entities. However, the costs involved in collecting psychological evaluations for the sheer number of entities that exist mean that they are prohibitively impractical. In order to avoid this problem, the present article examines three types of models: a category-based neural network model, a category-based Bayesian model, and a feature-based neural network model. These models utilize the results of a statistical analysis of a Japanese corpus computing co-occurrence probabilities for word pairs, rather than using psychological evaluations. Argument strength ratings collected by a psychological experiment were found to correlate well with simulations for the category-based neural network model.     

Overtraining, extinction and shift learning in a concurrent discrimination in rats

Two experiments examined the influence of overtraining on the reversal of a concurrent discrimination. After rats are trained to criterion on two different discriminations in the same apparatus, the reversal of one of these proceeds more rapidly than when both are reversed. If the reversal is conducted after overtraining on the original discriminations, then the opposite pattern of results is observed. That is, learning about the reversal of both discriminations is more rapid than when only a single discrimination is reversed. Experiment 1 replicated this effect and suggested that it is not caused by differences in the rate of extinction during reversal learning. In order to test a cue-association account for these findings, Experiment 2 examined the effect of exchanging the negative stimuli of a concurrent discrimination. This manipulation had a disruptive influence on performance, but only when subjects were not overtrained on the original discrimination.     

Transfer of Learning Between Concurrent and Matching (or Non-matching)-to-Sample Discriminations in Rats

Three experiments examined transfer of learning between a concurrent discrimination and a matching (or non-matching)-to-sample discrimination in rats. In Experiment 1, rats were trained to criterion (group NOT) or were overtrained (group OT) on two concurrent discriminations. Subsequently, group OT learned a matching (or non-matching) task more rapidly than did group NOT. In Experiment 2, rats were initially given matching (or nonmatching) tasks and then given whole or half reversal with these tasks. Group whole reversed faster than group half. In Experiment 3, two groups of rats were trained on matching (or non-matching) tasks, and then given concurrent discrimination training, followed by either whole or half reversal training (groups matching and non-matching). Another group (group control) received a pseudo-discrimination followed by the same training in Phases 2 and 3 as groups matching and non-matching. In groups matching and non-matching, rats learned the whole reversal more rapidly than the half reversal. But the opposite result was observed in group control. These findings suggest that transfer effects reported in Experiments 1 and 2 are governed by the same mechanism for the formation of associations between stimuli.     

Effects of overtraining on reversal learning by rats in concurrent and single discriminations

Two experiments examined the whole-partial effect of overtraining in concurrent discriminations and assessed the effect against single discrimination training in rats. In Experiment 1 overtraining facilitated reversal in Group W, in which rats were given concurrent training on two simultaneous discrimination tasks (A and B) in original learning before both tasks were reversed. By contrast, overtraining delayed reversal in Group P, in which animals were given the same training as in Group W in original learning, but only Task A was reversed. After overtraining, Group W reversed more rapidly than Group P. Without overtraining, Group P reversed more rapidly than both Group W and Group C, in which animals were trained only on Task A before this task was reversed. Experiment 2 investigated the effects of overtraining on the reversal of a successive discrimination in Groups W, P, and C. In addition, animals in a further group, Group S, received the same concurrent training as Group W before Task B was omitted and Task A reversed. Overtraining facilitated reversal in Groups W, C, and S but delayed it in Group P. After overtraining, Group W reversed more rapidly than Groups P, S, and C. Both Groups S and C also reversed more rapidly than did Group P. Without overtraining, Group P reversed more rapidly than Groups W, S, and C. There were no significant differences in reversal performance among Groups W, S, and C. These findings indicate that the effects of overtraining on reversal learning in concurrent discriminations differ from those observed in single discriminations.     

The Influence of Contraction Types on the Relationship Between the Intended Force and the Actual Force

Abstract

It has been demonstrated that the intended force (subjective estimation of force) does not always match to actual force without external feedback. The purpose of this study was to compare the influence of ballistic and tonic contractions on the relationship between the intended and actual force. Subjects produced isometric force at requested percentages of their MVC (20, 40, 60 and 80%) based on subjective estimation of force under two conditions (tonic and ballistic conditions). The tonic condition was to maintain force production, whereas the ballistic condition was to produce force as fast as possible. As a result, the actual force amplitude, the coefficient of variance and EMG amplitude were larger under the ballistic contraction compared with the tonic condition, even the same intended force levels. These results suggest that different motor unit activity and control systems in the ballistic and tonic contractions could alter the relationship between the intended force and the actual force.