Inhibitory Control in Children with Frontal Infarcts Related to Sickle Cell Disease

Evidence from past studies indicates that children with traumatic brain injury experience difficulties with inhibitory control. Less is known about inhibitory control in children with frontal brain injury related to cerebral infarction. We compared the inhibitory performance of children with frontal infarcts related to sickle cell disease with that of a control group of children with sickle cell disease but no history of cerebral infarction. On a stimulus-response reversal task, children with frontal infarcts made significantly more accuracy errors in the inhibitory condition than controls. Findings from this study and from previous research suggest that impairments in inhibitory control are common following frontal injury in a range of pediatric populations.     

Association between biological markers of sickle cell disease and cognitive functioning amongst Cameroonian children

Background: Some of the major complications of sickle cell disease (SCD) occur in the brain and apart from overt stroke, patients also present with cognitive impairments. We sought to evaluate the prevalence of cognitive deficits as well as their biological predicting factors in young SCD patients in Cameroon.

Methods: The cognitive performances of Cameroonian SCD young patients were evaluated using a neuropsychological test battery assessing four domains of cognitive functioning (executive functions, attention, memory, and sensory-motor skills) previously adapted and normalized on healthy subjects in Yaoundé.

Findings: Up to 37.5% of the 96 SCD patients aged 6 to 24 years (M?=?13.5, SD?=?4.9) had mild-to-severe cognitive deficits. The cognitive deficits tend to increase with age. There was a significant effect of SCD on executive functions and attention, whereas SCD patients performed as well as controls on memory and sensory-motor skills tests. Structural equation models showed a significant association between (a) severe anemia and lower executive functioning, (b) low fetal hemoglobin levels and lower executive functioning and attention, (c) history of cerebrovascular accidents and lower performances in executive functioning, sensory-motor skills, and memory, (d) pathological electroencephalogram and lower attention, and (e) abnormal Transcranial Doppler and lower memory.

Conclusion: SCD patients in Cameroon presented a very high prevalence of cognitive deficits, with a specific impairment of executive functions and attention. Routine neuropsychological evaluation for early detection of cognitive deficits in SCD patients could represent a cost-effective tool to implement in resource-limited contexts such as in sub-Saharan Africa.     

Connection between deformation-induced dislocation substructures and martensite formation in stainless steel

We report a quantitative connection between the strain amplitude dependencies of the organisation of dislocation cell substructures with the formation of deformation-induced martensite during cyclic plasticity of austenitic stainless steel at ambient temperature.     

THE ABSTRACT SUBLIME: Life as information waiting to be rewritten

We report here on a series of interaction-intensive, interdisciplinary workshops to foster collaboration among those who teach, study, and engage with the public about scientific developments and social change—the New England Workshop on Science and Social Change. We include one line of thinking that fed into the workshops and present an analysis of how they contribute to participants developing their interest and skills in collaboration. Workshop evaluations suggest that people are moved to develop themselves as collaborators when they view an experience or training as transformative. Four R's—respect, risk, revelation, and re-engagement—point to the important conditions for interactions among researchers to be experienced as transformative. Three considerations lie behind the focus on the process side of the workshops, not the specific workshop topics: (1) how best to fill in for readers what they missed out on by not being there; (2) workshops and meetings are a ubiquitous part of the culture of science and technology studies (STS) so it is valuable to examine this aspect of our own culture with a view to promoting positive changes; and (3) in some scientific fields organized multi-person collaborative processes form a highly valorized aspect of the culture of science, so reflection on experiences of participation and collaboration in STS might inform our analyses of fields that emphasize collaboration and group processes. Indeed, the authors' own involvement in the workshops extends our own STS work on actor networks and ‘heterogeneous engineering’, that is, the mobilization of a variety of resources by diverse agents spanning different realms of social action.     

Neural Computation and the Computational Theory of Cognition

We begin by distinguishing computationalism from a number of other theses that are sometimes conflated with it. We also distinguish between several important kinds of computation: computation in a generic sense, digital computation, and analog computation. Then, we defend a weak version of computationalism—neural processes are computations in the generic sense. After that, we reject on empirical grounds the common assimilation of neural computation to either analog or digital computation, concluding that neural computation is sui generis. Analog computation requires continuous signals; digital computation requires strings of digits. But current neuroscientific evidence indicates that typical neural signals, such as spike trains, are graded like continuous signals but are constituted by discrete functional elements (spikes); thus, typical neural signals are neither continuous signals nor strings of digits. It follows that neural computation is sui generis. Finally, we highlight three important consequences of a proper understanding of neural computation for the theory of cognition. First, understanding neural computation requires a specially designed mathematical theory (or theories) rather than the mathematical theories of analog or digital computation. Second, several popular views about neural computation turn out to be incorrect. Third, computational theories of cognition that rely on non‐neural notions of computation ought to be replaced or reinterpreted in terms of neural computation.     

The Modulation of Visual and Task Characteristics of a Writing System on Hemispheric Lateralization in Visual Word Recognition—A Computational Exploration

Through computational modeling, here we examine whether visual and task characteristics of writing systems alone can account for lateralization differences in visual word recognition between different languages without assuming influence from left hemisphere (LH) lateralized language processes. We apply a hemispheric processing model of face recognition to visual word recognition; the model implements a theory of hemispheric asymmetry in perception that posits low spatial frequency biases in the right hemisphere and high spatial frequency (HSF) biases in the LH. We show two factors that can influence lateralization: (a) Visual similarity among words: The more similar the words in the lexicon look visually, the more HSF/LH processing is required to distinguish them, and (b) Requirement to decompose words into graphemes for grapheme‐phoneme mapping: Alphabetic reading (involving grapheme‐phoneme conversion) requires more HSF/LH processing than logographic reading (no grapheme‐phoneme mapping). These factors may explain the difference in lateralization between English and Chinese orthographic processing.     

诱导多能干细胞技术的生命伦理分析

诱导多能干细胞(induced pluripotent stem cells,iPSCs)是通过向分化的体细胞转入特定的外源转录因子进行重编程,从而获得具有自我更新能力和多能性的细胞.iPSCs具有形成体内所有细胞类型的潜能,尤其是能以患者自身体细胞制备iPSCs,可用于特定疾病的治疗,规避了异体移植引发的免疫排斥风险以及伦理和法律冲突等问题,在基础研究和临床应用都有广阔的应用前景.目前,在重编程体细胞为iPSCs的过程中,由于细胞来源不同,所采用的基因组合以及转基因方式各不相同,获得的iPSCs具有潜在的致癌性等安全隐患,导致iPSCs的临床应用面临新的生命伦理挑战.     

Salutary effect of daily coping self-efficacy: impact on day-by-day coping to mood effects within dyads following hematopoietic stem cell transplantation

ABSTRACT

Background and Objectives: Little is known how coping self-efficacy (CSE) interacts with coping in dyad everyday life. The present study examined the moderating role of daily CSE in the relationship between coping and the next-day positive (PA) or negative (NA) affect in patient-caregiver dyads, following hematopoietic stem cell transplantation.

Design: This intensive longitudinal study was conducted during the first 28 days after post-transplant discharge.

Methods: Patients and their caregivers (N?=?200) maintained daily diaries on CSE, coping strategies, and affect.

Results: Daily CSE moderated daily coping–affect relationship: Positive emotion-focused coping increased PA in patients with higher than usual emotion-related CSE, whereas a buffering effect was found at lower than usual emotion-related CSE. A positive association between negative emotion-focused coping and NA in both patients and caregivers was stronger among those with lower than usual levels of emotion-related CSE. Higher than usual instrumental coping reduced NA in patients whose caregivers had higher than usual problem-related CSE, but increased NA for those whose caregivers had lower than usual instrumental CSE.

Conclusion: The findings show that daily CSE contributes to the effectiveness of daily coping within dyad, confirming its significance in effective adaptation and the role in the dyadic coping process.     

Intelligence is differentially related to neural effort in the task-positive and the task-negative brain network

Previous studies on individual differences in intelligence and brain activation during cognitive processing focused on brain regions where activation increases with task demands (task-positive network, TPN). Our study additionally considers brain regions where activation decreases with task demands (task-negative network, TNN) and compares effects of intelligence on neural effort in the TPN and the TNN. In a sample of 52 healthy subjects, functional magnetic resonance imaging was used to determine changes in neural effort associated with the processing of a working memory task. The task comprised three conditions of increasing difficulty: (a) maintenance, (b) manipulation, and (c) updating of a four-letter memory set. Neural effort was defined as signal increase in the TPN and signal decrease in the TNN, respectively. In both functional networks, TPN and TNN, neural effort increased with task difficulty. However, intelligence, as assessed with Raven's Matrices, was differentially associated with neural effort in the TPN and TNN. In the TPN, we observed a positive association, while we observed a negative association in the TNN. In terms of neural efficiency (i.e., task performance in relation to neural effort expended on task processing), more intelligent subjects (as compared to less intelligent subjects) displayed lower neural efficiency in the TPN, while they displayed higher neural efficiency in the TNN. The results illustrate the importance of differentiating between TPN and TNN when interpreting correlations between intelligence and fMRI measures of brain activation. Importantly, this implies the risk of misinterpreting whole brain correlations when ignoring the functional differences between TPN and TNN.     

Deep learning and punctuated equilibrium theory

Deep learning is associated with the latest success stories in AI. In particular, deep neural networks are applied in increasingly different fields to model complex processes. Interestingly, the underlying algorithm of backpropagation was originally designed for political science models. The theoretical foundations of this approach are very similar to the concept of Punctuated Equilibrium Theory (PET). The article discusses the concept of deep learning and shows parallels to PET. A showcase model demonstrates how deep learning can be used to provide a missing link in the study of the policy process: the connection between attention in the political system (as inputs) and budget shifts (as outputs).