实验性恶心与呕吐——大脑皮层与内脏相关研究的新途径

大脑皮层与内脏关系的脑机制是揭示心身疾病和心理疾病的重要依据。本文综述了经典条件学习与期待性恶心与呕吐的关系以及实验性恶心与呕吐的研究方法。作者认为,实验性恶心与呕吐结合脑成像技术是研究大脑皮层与内脏关系神经机制的重要途径。     

Consistency in physiological stress responses and electromyographic activity during induced stress exposure in women and men

Physiological responses serve the role as objective indicators of stress as well as a link between psychosocial stress and various health outcomes. The aim of the present exposure session was to compare different physiological stress responses (systolic and diastolic blood pressure, heart rate, urinary epinephrine and norepinephrine, salivary cortisol) as well as trapezius muscle activity, measured by surface electromyography, during mental and physical stress in 11 women and ten men. The results show significantly increased activity in all measures but cortisol and significant associations between sympathetic arousal and EMG activity. The association between sympathetic arousal and muscle activity is of importance for understanding the high prevalence of musculoskeletal disorders in mentally stressful but physically light work tasks. Men had higher blood pressure and a more pronounced increase in epinephrine output than women, whereas women had higher heart rate. It was concluded that sympathetic activity is more sensitive to moderately intense stress exposure than pituitary adrenocortical (cortisol) activity and that men respond to performance stress with more epinephrine output than women. Although the correlations between the different indicators of sympathetic arousal were high, together they could still only explain 30–70% of the inter-individual variance. Thus, several parameters are needed in order to obtain a reliable measure of sympathetic activity.     

Emergence from brain architectures: a new cognitive science?

The way in which artificial intelligence has developed over the last 50 years has had a major role in shaping cognitive science as it is today. This has generated computational models of behaviour. The connectionist revival of the 1980s added a tinge of neurodynamics to this. Here I suggest that some post-connectionist work in artificial intelligence is turning towards an understanding and formalisation of the mechanisms of brain architectures which contribute to an emergence of cognition providing a closer link between brain mechanisms and experienced brain states. This even addresses the neurological basis of consciousness.     

Smoking reduces language lateralization: a dichotic listening study with control participants and schizophrenia patients

Schizophrenia has been associated with deficits in functional brain lateralization. According to some authors, the reduction of asymmetry could even promote this psychosis. At the same time, schizophrenia is accompanied by a high prevalence of nicotine dependency compared to any other population. This association is very interesting, because sex-dependent effects of smoking in auditory language asymmetries have been reported recently, and the verbal domain is also one major focus in cognitive deficit studies of schizophrenia. Thus, the altered laterality pattern in schizophrenia could, at least in part, result from secondary artefacts due to smoking rather than being a pure cause of the disease itself. To test this hypothesis, the present study examined auditory language lateralization in 67 schizophrenia patients and in 72 healthy controls in a phonemic and an emotional dichotic listening task. Our findings replicate previous research, in that smoking reduces language lateralization in men in phonemic dichotic listening. In addition, we show that smoking also reduces laterality in women in the emotional dichotic listening task. Thus, smoking alters phonemic and emotional language asymmetries differentially for men and women, with a stronger effect for men in the left hemisphere phonemic task, and a stronger effect for women in the right hemisphere emotional task. Together, these findings point towards an effect of smoking which is possibly independent of sex and hemisphere. Importantly, by testing equal numbers of smoking and non-smoking patients and controls, we found no schizophrenia-associated asymmetry effect. Possible neurobiological mechanisms with which smoking may alter auditory microcircuits and thereby diminish left-right differences are discussed.     

小麦中烟曲霉生长温度与水分活度预测模型的建立

为快速预测和监控引起小麦霉变的烟曲霉的生长,在15～40℃温度及0.70～0.96水分活度下进行小麦储藏模拟实验,建立和验证烟曲霉D6生长的一级和二级预测模型。结果表明,一级生长模型中Bo-ltsmann模型优于Logistic模型。以Boltsmann模型拟合数据建立二级模型,采用平方根模型拟合,得烟曲霉D6的最低生长温度和水分活度分别为5.784℃和0.721。经验证,平方根模型能较好描述烟曲霉D6最大比生长速率与温度、水分活度之间的对应关系。     

Towards a computational theory of experience

A standing challenge for the science of mind is to account for the datum that every mind faces in the most immediate – that is, unmediated – fashion: its phenomenal experience. The complementary tasks of explaining what it means for a system to give rise to experience and what constitutes the content of experience (qualia) in computational terms are particularly challenging, given the multiple realizability of computation. In this paper, we identify a set of conditions that a computational theory must satisfy for it to constitute not just a sufficient but a necessary, and therefore naturalistic and intrinsic, explanation of qualia. We show that a common assumption behind many neurocomputational theories of the mind, according to which mind states can be formalized solely in terms of instantaneous vectors of activities of representational units such as neurons, does not meet the requisite conditions, in part because it relies on inactive units to shape presently experienced qualia and implies a homogeneous representation space, which is devoid of intrinsic structure. We then sketch a naturalistic computational theory of qualia, which posits that experience is realized by dynamical activity-space trajectories (rather than points) and that its richness is measured by the representational capacity of the trajectory space in which it unfolds.     

« Femmes au volant,danger au tournant » Les conductrices sont-elles victimes d’une menace de stéréotype ?

Owing to the sexuation of occupations associating technical attributes with men and relational skills with women, the latter are less numerous in professions where driving is involved. The negative stereotype associating women with poor driving skills is thus likely to have a cognitive and behavioral impact. According to the model of the stereotype threat, could activation of the threat inhibit the performance of women in a Highway Code test? After performing an association task that demonstrated a largely negative stereotype, 56 female students took a Highway Code test in two conditions: an experimental condition where the stereotype was activated by a comparison between men and women (N = 17); and a control condition without activation (N = 39). Subjects performed less well in the experimental condition, demonstrating the expected effects of the stereotype threat.     

Quelles méthodes et quelle modélisation d’analyse de l’activité de travail de l’encadrement ? L’exemple de l’encadrement des chantiers de la construction

By referring to the ergonomic analysis of work and to the management sciences, the authors propose an analysis model of the managers’ activity. Until then, few researchs were realized in ergonomics science with this population which has to prepare and to organize the works of other operators. According to the authors, it is possible to apply to this population the model of “the centre de décision”. It allows to understand how their activity is determined by “upstream” centres and then how it determines the activity of centres “approval”. Applied to the project and site managers, this model brings solutions to transform their work and the work of the workmen.     

The vocational well-being of workers with childhood onset of disability: Life satisfaction and perceived workplace discrimination

Workers with disabilities are understudied, and workers with childhood onset of disability have been excluded from many of the studies on disability and work that do exist. This research compares the effects of childhood and adult onset of disability in a nationally representative sample of workers with disabilities. Educational disruptions due to disability status in childhood are negatively associated with life satisfaction and positively associated with perceived discrimination. Although age is associated with increased life satisfaction and decreased perceptions of discrimination for workers with adult disability onset, age is unrelated to these outcomes for workers with childhood disability onset. Receiving workplace accommodations is positively associated with satisfaction and negatively associated with discrimination for both groups, however, these relationships are stronger in magnitude for the childhood disability onset group. Organizational environments, both in education and in the workplace, play a critical role in the vocational well-being of workers with childhood disability onset.     

Sleep EEG changes during adolescence: An index of a fundamental brain reorganization

Delta (1–4 Hz) EEG power in non-rapid eye movement (NREM) sleep declines massively during adolescence. This observation stimulated the hypothesis that during adolescence the human brain undergoes an extensive reorganization driven by synaptic elimination. The parallel declines in synaptic density, delta wave amplitude and cortical metabolic rate during adolescence further support this model. These late brain changes probably represent the final ontogenetic manifestation of nature’s strategy for constructing nervous systems: an initial overproduction of neural elements followed by elimination. Errors in adolescent brain reorganization may cause mental illness; this could explain the typical age of onset of schizophrenia. Longitudinal studies of sleep EEG are enhancing our knowledge of adolescent brain maturation. Our longitudinal study of sleep EEG changes in adolescence showed that delta power, which may reflect frontal cortex maturation, begins its decline between ages 11 and 12 years and falls by 65% by age 17 years. In contrast, NREM theta power begins its decline much earlier. Delta and theta EEG frequencies are important to sleep theory because they behave homeostatically. Surprisingly, these brain changes are unrelated to pubertal maturation but are strongly linked to age. In addition to these (and other) maturational EEG changes, sleep schedules in adolescence change in response to a complex interaction of circadian, social and other influences. Our data demonstrate that the daytime sleepiness that emerges in adolescence is related to the decline in NREM delta as well as to altered sleep schedules. These longitudinal sleep data provide guideposts for studying cognitive and behavioral correlates of adolescent brain reorganization.