A technique based on trade‐off maps to visualise and analyse relationships between objectives in optimisation problems

Understanding the relationships between objectives in a multiobjective optimisation problem is important for developing tailored and efficient solving techniques. In particular, when tackling combinatorial optimisation problems with many objectives, that arise in real‐world logistic scenarios, better support for the decision maker can be achieved through better understanding of the often complex fitness landscape. This paper makes a contribution in this direction by presenting a technique that allows a visualisation and analysis of the local and global relationships between objectives in optimisation problems with many objectives. The proposed technique uses four steps: First, the global pairwise relationships are analysed using the Kendall correlation method; then, the ranges of the values found on the given Pareto front are estimated and assessed; next, these ranges are used to plot a map using Gray code, similar to Karnaugh maps, that has the ability to highlight the trade‐offs between multiple objectives; and finally, local relationships are identified using scatter plots. Experiments are presented for three combinatorial optimisation problems: multiobjective multidimensional knapsack problem, multiobjective nurse scheduling problem, and multiobjective vehicle routing problem with time windows . Results show that the proposed technique helps in the gaining of insights into the problem difficulty arising from the relationships between objectives.     

工作记忆负荷、形状干扰对聋人与听力正常人注意捕获影响的眼动研究

通过记录和分析被试的行为和眼动指标,本研究试图探讨不同工作记忆负荷下,形状干扰对聋人与听力正常人不同视野位置上刺激信息捕获注意的异同。研究结果表明：（1）形状干扰刺激虽然没有影响被试视觉加工的认知绩效,但被试的眼动模式会由于工作记忆负荷的改变而改变,高工作记忆负荷时,有形状干扰的注视次数高于无形状干扰。（2）工作记忆负荷、视野位置影响被试视觉加工任务的完成,被试在不同视野位置的加工过程表现出不一致的眼动模式。（3）聋人视觉加工在高工作记忆负荷时存在一定的劣势,但其对不同视野位置的信息加工及形状干扰所产生的注意捕获效应与听力正常人一致。     

Cognitive deficits in relation to personality type and hypothalamic-pituitary-adrenal (HPA) axis dysfunction in women with stress-related exhaustion

Exhaustion caused by long-term work-related stress may cause cognitive dysfunction. We explored factors that may link chronic stress and cognitive impairment. Personality, psychiatric screening, and behavior were assessed by self-reporting measures in 20 female patients (mean age 39.3 years; range 26-53) with a preliminary diagnosis of stress-related exhaustion and in 16 healthy matched controls. Cognitive performance was investigated with a detailed neuropsychological test battery. Cortisol axis function was assessed by urinary and saliva collections of cortisol, dexamethasone suppression, Synacthen response, and corticotropin-releasing hormone (CRH) tests. Proinflammatory cytokines were measured. Hippocampal volumes were estimated by magnetic resonance imaging. Multivariate and univariate statistical methods were used to explore putative differences between groups and factors linked to cognitive impairment. Cognitive function clearly differed between groups, with decreased attention and visuospatial memory in the patient group, suggesting frontal cortex/medial temporal cortex-network dysfunction. Increased harm avoidance and persistence was present among patients, with lowered self-directedness linked to lower quality of life, increased anxious and depressive tendencies, and experiences of psychosocial stress. Attention was decreased with concomitantly impaired visuospatial memory. The pituitary (adrenocorticotropic hormone, ACTH) response to CRH was decreased in patients, with an increased cortisol/ACTH response to CRH. However, cortisol production rates, diurnal or dexamethasone-suppressed saliva cortisol levels, and the cortisol response to Synacthen were unaltered. Hippocampal volumes did not differ between groups. These findings suggest that cognitive dysfunction in stress-related exhaustion is linked to distinct personality traits, low quality of life, and a decreased ACTH response to CRH.     

Magnitude and chronometry of neural mechanisms of emotion regulation in subtypes of aggressive children

Emotion regulation is a key social skill and children who fail to master it are at risk for clinical disorders. Specific styles of emotion regulation have been associated with particular patterns of prefrontal activation. We investigated whether anxious aggressive children would reveal a different pattern of cortical activation than non-anxious aggressive children and normally-developing children. We examined the magnitude and timing of source activation underlying the N2—an ERP associated with inhibitory control—during a go/nogo task with a negative emotion induction component (loss of earned points). We estimated cortical activation for two regions of interest—a ventral prefrontal and a dorsomedial prefrontal region—for three 100-ms windows over the range of the N2 (200–500 ms). Anxious aggressive children showed high ventral prefrontal activation in the early window; non-anxious aggressive children showed high ventral prefrontal activation in the late window, but only for the duration of the emotion induction; and normally-developing children showed low ventral prefrontal activation throughout. There were no group differences in dorsomedial prefrontal activation. These results suggest that anxious aggressive children recruit ventral prefrontal activation quickly and indiscriminately, possibly giving rise to their rigid, threat-oriented approach to conflict. The late ventral prefrontal activation seen for non-anxious aggressive children may underlie a more delayed, situation-specific, but ineffective response to frustration.     

早期高级认知发展与前额叶功能发育的fNIRS研究

儿童早期阶段是各项认知能力和脑发育的关键阶段。近红外光谱成像技术(fNIRS)凭借其非侵害性、便捷操作以及对头动容忍度高等特点,在早期阶段儿童认知发展与脑发育的研究中得到越来越多的应用。从早期高级认知发展与前额叶功能的单侧优势变化、对应前额叶脑区逐渐专门化、发展关键期与前额叶功能的可塑性,以及前额叶功能异常与早期发展障碍的关系等四个方面对基于fNIRS技术开展的早期认知发展与脑发育的研究进展进行了梳理和分析。指出未来研究应探究儿童早期认知能力发展和脑发育的轨迹及关键期,探讨有发展性障碍家族风险儿童的早期大脑发育特点,为早期教育和发展障碍的早期预警提供依据。     

经颅直流电刺激在抑郁症治疗中的应用

已有的神经影像学研究成果揭示, 抑郁症发作的重要原因之一是大脑前额叶皮层结构和功能受损。经颅直流电刺激(tDCS)作为一种无创脑刺激, 选取前额叶皮层作为刺激区域, 通过调节皮层兴奋性来治疗抑郁症, 能够有效缓解抑郁症状和改善受损的认知功能, 疗效明显且持久稳定。针对tDCS在抑郁症治疗研究中的问题, 未来可从有效性、个体差异以及预防干预等六个方面进一步研究, 以期tDCS作为一种具有潜力的治疗手段, 在临床上有更为广泛地应用。     

内侧颞叶与来源记忆

来源记忆不同于项目记忆。早期的研究认为来源记忆的神经基础主要是前额叶,但近几年的相关研究发现内侧颞叶在来源记忆中的作用也是相当重要的,健康被试的功能神经成像研究和内侧颞叶损伤病人研究都为内侧颞叶在来源记忆中的作用提供了可靠证据。     

Evaluating Factorial Invariance: An Interval Estimation Approach Using Bayesian Structural Equation Modeling

In this study, we introduce an interval estimation approach based on Bayesian structural equation modeling to evaluate factorial invariance. For each tested parameter, the size of noninvariance with an uncertainty interval (i.e. highest density interval [HDI]) is assessed via Bayesian parameter estimation. By comparing the most credible values (i.e. 95% HDI) with a region of practical equivalence (ROPE), the Bayesian approach allows researchers to (1) support the null hypothesis of practical invariance, and (2) examine the practical importance of the noninvariant parameter. Compared to the traditional likelihood ratio test, simulation results suggested that the proposed Bayesian approach could offer additional insight into evaluating factorial invariance, thus, leading to more informative conclusions. We provide an empirical example to demonstrate the procedures necessary to implement the proposed method in applied research. The importance of and influences on the choice of an appropriate ROPE are discussed.