Word chunk frequencies affect the processing of pronominal object-relative clauses

We present experimental support for the view that fine-grained statistical information may play a crucial role in the processing of centre-embedded linguistic structure. Using both offline and online methods, we show that the processing of pronominal object-relative clauses is influenced by the frequency of co-occurrence of the word combinations (chunks) forming the clause. We use materials that are controlled for capacity-based factors that have been previously shown to influence comprehension of relative clauses. The results suggest that, other factors being equal, the frequency of the word chunk forming the clause affects processing difficulty. Analyses of the data indicate that the results cannot be explained by differential access to individual lexical items. Following recent constructivist approaches, we argue that frequency of co-occurrence influences the chunking mechanism by which multiword sequences may become fused into processing units that are easier to access.     

The secret is in the sound: from unsegmented speech to lexical categories

When learning language, young children are faced with many seemingly formidable challenges, including discovering words embedded in a continuous stream of sounds and determining what role these words play in syntactic constructions. We suggest that knowledge of phoneme distributions may play a crucial part in helping children segment words and determine their lexical category, and we propose an integrated model of how children might go from unsegmented speech to lexical categories. We corroborated this theoretical model using a two‐stage computational analysis of a large corpus of English child‐directed speech. First, we used transition probabilities between phonemes to find words in unsegmented speech. Second, we used distributional information about word edges – the beginning and ending phonemes of words – to predict whether the segmented words from the first stage were nouns, verbs, or something else. The results indicate that discovering lexical units and their associated syntactic category in child‐directed speech is possible by attending to the statistics of single phoneme transitions and word‐initial and final phonemes. Thus, we suggest that a core computational principle in language acquisition is that the same source of information is used to learn about different aspects of linguistic structure.     

Asking an eyewitness to predict their later lineup performance could harm the confidence–accuracy relationship

Few studies have investigated eyewitnesses' ability to predict their later lineup performance, known as predecision confidence. We applied calibration analysis in two experiments comparing predecision confidence (immediately after encoding but prior to a lineup) to postdecision confidence (immediately after a lineup) to determine which produces a superior relationship with lineup decision accuracy. Experiment 1 (N = 177) featured a multiple-block lineup recognition paradigm featuring several targets and lineups; Experiment 2 featured an eyewitness identification paradigm with a mock-crime video and a single lineup for each participant (N = 855). Across both experiments, postdecision confidence discriminated well between correct and incorrect lineup decisions, but predecision confidence was a poor predictor of accuracy. Moreover, simply asking for predecision confidence weakened the postdecision confidence–accuracy relationship. This implies that police should exercise caution when interviewing eyewitnesses, as they should not be asked to predict their ability to make an accurate lineup decision.     

Hormonal,anthropometrical, and behavioral correlates of physical aggression in !Kung San men of Namibia

Differences in physical aggression among 114 male !Kung San (bushmen) from Namibia were investigated with regard to sex hormone levels, body dimensions, consumption of alcohol, and degree of acculturation. Subjects were classified from injuries resulting from prior conflicts with mutual physical aggression between the opponents as either violent or nonviolent. The comparison of mean sex hormone values (total serum testosterone, T_ser; serum 5α-dihydrotestosterone, DHT; serum estradiol 17β, E₂; “free,” non-SHBG-bound salivary testosterone, T_sal) and hormone ratios (T_sal/T_ser; DHT/T_ser) did not yield any significant differences between the violent and nonviolent group. However, correlation coefficients of sex hormone levels with the frequency of violent behavior within the group of physically aggressive San men were significantly positive for DHT, T_sal, and T_sal/T_ser (P < .05) while T_ser, E₂, and DHT/T_ser showed only weak positive correlations. Moreover, the violent men exhibit higher mean values in certain measures of physical robustness which may point to a possible pathway of indirect androgen action on human aggression. When the probands were classified according to their drinking habits, usually abstinent men had shown significantly less violent behavior in the past than men who habitually consume alcohol.     

Toward a better understanding of the effects of hindrance and challenge stressors on work behavior

This study investigated the processes whereby hindrance and challenge stressors may affect work behavior. Three mechanisms were examined to explain the differential effects these stressors have demonstrated: job satisfaction, strains, and work self-efficacy. A model is proposed in which both types of stressors will result in increases in strains, but that job satisfaction is primarily involved in the relationship between hindrance stressors and citizenship behavior, and efficacy is involved in the relationship between challenge stressors and job performance. Although the results generally supported the dual-stressor framework showing meaningful relationships to the work outcomes through the proposed processes, the link between work self-efficacy and job performance was not significant. This model was analyzed using multi-source data collected from 143 employees from a variety of organizational settings. Implications for the conceptualization of stressors and the development of interventions are discussed.     

Science-Based Neurorehabilitation: Recommendations for Neurorehabilitation From Basic Science

ABSTRACT

Neuroscience has fundamentally changed the understanding of learning and memory within recent years. Here, the authors discuss a number of specific areas where they believe new understanding of the CNS from basic science is having a fundamental impact on neurorehabilitation and is leading to new therapeutic approaches. These areas have constituted a basis for development of some basic principles for neurorehabilitation: Optimal rehabilitation should involve (a) active (patient) participation in the training, (b) training that does not only involve many repetitions, but also continues to challenge the skill of the training person, (c) motivation and reward, (d) intensive training and practice over a long time, (e) careful organization of the training in relation to other activities, and (f) incorporation of other potentially beneficial parameters such as sleep and diet. It should in this relation also be pointed out that albeit neurorehabilitation may be predicted to have the most optimal effect early in life and as soon after injury as possible, there is no reason to believe that beneficial effects of training may not be obtained late in life or several years after injury.     

Sequential learning in non-human primates

Sequential learning plays a role in a variety of common tasks, such as human language processing, animal communication, and the learning of action sequences. In this article, we investigate sequential learning in non-human primates from a comparative perspective, focusing on three areas: the learning of arbitrary, fixed sequences; statistical learning; and the learning of hierarchical structure. Although primates exhibit many similarities to humans in their performance on sequence learning tasks, there are also important differences. Crucially, non-human primates appear to be limited in their ability to learn and represent the hierarchical structure of sequences. We consider the evolutionary implications of these differences and suggest that limitations in sequential learning may help explain why non-human primates lack human-like language.