Do Questions Get Infants Talking? Infant Vocal Responses to Questions and Declaratives in Maternal Speech

Maternal questions play a crucial role in early language acquisition by virtue of their special grammatical, prosodic and lexical forms, and their abundance in the input. Infants are able to discriminate questions from other sentence types and produce rising intonations in their own requests. This study examined whether caregiver questions were related to the quantity of infant vocalizations. Thirty‐six infants aged 10 and 14 months participated in a laboratory play session with their mothers. In separate blocks, mothers were instructed to ask questions and to refrain from asking questions. Both block‐level and utterance‐level analyses found no evidence that maternal questions affected the amount of infant‐response vocalizations. Mothers of 14‐month‐olds (but not 10‐month‐olds) tended to repeat questions. Copyright © 2016 John Wiley & Sons, Ltd.     

奖赏对海洛因成瘾者执行功能的影响机制

一些研究发现海洛因成瘾者奖赏失调表现为:对海洛因相关线索的注意偏向、渴求感增加,对金钱奖赏表现出"即时收益优先"的高风险决策模式和对长时收益的敏感性降低。另一些研究发现海洛因成瘾者的执行功能存在障碍。奖赏失调和执行功能障碍在成瘾物质使用的维持和复吸中起着重要作用。双重竞争模型认为奖赏和执行功能的交互作用决定着行为的结果,但是奖赏对海洛因成瘾者执行功能的影响机制还不清楚。因此,拟使用事件相关电位技术来考察海洛因相关线索和金钱奖赏对不同戒断期成瘾者执行功能的影响机制,短期(1~3个月)、长期(18个月以上)海洛因戒断者和健康对照组被比较。这不仅有助于构建完善的成瘾理论体系,还有助于确定临床戒断后复吸的风险因素和不同戒断期的治疗目标。     

Study of behavioural and neural bases of visuo‐spatial working memory with an fMRI paradigm based on an n‐back task

The goal of this study was to propose a new functional magnetic resonance imaging (fMRI) paradigm using a language‐free adaptation of a 2‐back working memory task to avoid cultural and educational bias. We additionally provide an index of the validity of the proposed paradigm and test whether the experimental task discriminates the behavioural performances of healthy participants from those of individuals with working memory deficits. Ten healthy participants and nine patients presenting working memory (WM) deficits due to acquired brain injury (ABI) performed the developed task. To inspect whether the paradigm activates brain areas typically involved in visual working memory (VWM), brain activation of the healthy participants was assessed with fMRIs. To examine the task's capacity to discriminate behavioural data, performances of the healthy participants in the task were compared with those of ABI patients. Data were analysed with GLM‐based random effects procedures and t‐tests. We found an increase of the BOLD signal in the specialized areas of VWM. Concerning behavioural performances, healthy participants showed the predicted pattern of more hits, less omissions and a tendency for fewer false alarms, more self‐corrected responses, and faster reaction times, when compared with subjects presenting WM impairments. The results suggest that this task activates brain areas involved in VWM and discriminates behavioural performances of clinical and non‐clinical groups. It can thus be used as a research methodology for behavioural and neuroimaging studies of VWM in block‐design paradigms.     

Extraversion modulates functional connectivity hubs of resting‐state brain networks

Personality dimension extraversion describes individual differences in social behaviour and socio‐emotional functioning. The intrinsic functional connectivity patterns of the brain are reportedly associated with extraversion. However, whether or not extraversion is associated with functional hubs warrants clarification. Functional hubs are involved in the rapid integration of neural processing, and their dysfunction contributes to the development of neuropsychiatric disorders. In this study, we employed the functional connectivity density (FCD) method for the first time to distinguish the energy‐efficient hubs associated with extraversion. The resting‐state functional magnetic resonance imaging data of 71 healthy subjects were used in the analysis. Short‐range FCD was positively correlated with extraversion in the left cuneus, revealing a link between the local functional activity of this region and extraversion in risk‐taking. Long‐range FCD was negatively correlated with extraversion in the right superior frontal gyrus and the inferior frontal gyrus. Seed‐based resting‐state functional connectivity (RSFC) analyses revealed that a decreased long‐range FCD in individuals with high extraversion scores showed a low long‐range functional connectivity pattern between the medial and dorsolateral prefrontal cortex, middle temporal gyrus, and anterior cingulate cortex. This result suggests that decreased RSFC patterns are responsible for self‐esteem, self‐evaluation, and inhibitory behaviour system that account for the modulation and shaping of extraversion. Overall, our results emphasize specific brain hubs, and reveal long‐range functional connections in relation to extraversion, thereby providing a neurobiological basis of extraversion.     

Neural substrates of the ‘low‐level’ system for speech articulation: Evidence from primary opercular syndrome

We describe a patient with progressive disorder of speech, without language impairment (opercular syndrome). Morphometric analysis confirmed asymmetric volume reduction of the precentral areas (>left). Diffusion imaging showed significant white matter changes in the left frontal lobe, with specific involvement of the left corticobulbar tract and connections between supplementary/pre‐supplementary motor areas and the frontal operculum (frontal aslant tract). We suggest that the organization of expressive language includes a ‘low level’ motor system principally distributed in the left hemisphere that shows specific susceptibility to neurodegeneration, distinct from neural systems subtending praxic, and cognitive aspects of language.     

Distance stability analysis in multidimensional scaling using the jackknife method

Stability or sensitivity analysis is an important topic in data analysis that has received little attention in the application of multidimensional scaling (MDS), for which the only available approaches are given in terms of a coordinate‐based analytical jackknife methodology. Although in MDS the prime interest is in assessing the stability of the points in the configuration, this methodology may be influenced by imprecisions resulting from the inherently necessary Procrustes method. This paper proposes an analytical distance‐based jackknife procedure to study stability and cross‐validation in MDS in terms of the jackknife distances, which is not influenced by the Procrustes method. For each object, the corresponding jackknife estimated points are considered as naturally clustered points, and stability and cross‐validation are analysed in terms of the MDS distances arising from the jackknife procedure, on the basis of a weighted cluster‐MDS algorithm. A jackknife‐relevant configuration is also proposed for cross‐validation in terms of coordinates, in a cluster‐MDS framework.     

Developing new online calibration methods for multidimensional computerized adaptive testing

Multidimensional computerized adaptive testing (MCAT) has received increasing attention over the past few years in educational measurement. Like all other formats of CAT, item replenishment is an essential part of MCAT for its item bank maintenance and management, which governs retiring overexposed or obsolete items over time and replacing them with new ones. Moreover, calibration precision of the new items will directly affect the estimation accuracy of examinees’ ability vectors. In unidimensional CAT (UCAT) and cognitive diagnostic CAT, online calibration techniques have been developed to effectively calibrate new items. However, there has been very little discussion of online calibration in MCAT in the literature. Thus, this paper proposes new online calibration methods for MCAT based upon some popular methods used in UCAT. Three representative methods, Method A, the ‘one EM cycle’ method and the ‘multiple EM cycles’ method, are generalized to MCAT. Three simulation studies were conducted to compare the three new methods by manipulating three factors (test length, item bank design, and level of correlation between coordinate dimensions). The results showed that all the new methods were able to recover the item parameters accurately, and the adaptive online calibration designs showed some improvements compared to the random design under most conditions.