38 resultados para Executive dysfunction
Resumo:
We argue that hyper-systemizing predisposes individuals to show talent, and review evidence that hyper-systemizing is part of the cognitive style of people with autism spectrum conditions (ASC). We then clarify the hyper-systemizing theory, contrasting it to the weak central coherence (WCC) and executive dysfunction (ED) theories. The ED theory has difficulty explaining the existence of talent in ASC. While both hyper-systemizing and WCC theories postulate excellent attention to detail, by itself excellent attention to detail will not produce talent. By contrast, the hyper-systemizing theory argues that the excellent attention to detail is directed towards detecting 'if p, then q' rules (or [input-operation-output] reasoning). Such law-based pattern recognition systems can produce talent in systemizable domains. Finally, we argue that the excellent attention to detail in ASC is itself a consequence of sensory hypersensitivity. We review an experiment from our laboratory demonstrating sensory hypersensitivity detection thresholds in vision. We conclude that the origins of the association between autism and talent begin at the sensory level, include excellent attention to detail and end with hyper-systemizing.
Resumo:
Notes that the central executive lies at the heart of A. D. Baddeley's theory of working memory, but that what it does has been characterized in several different ways. This chapter reviews and brings together various interpretations of central executive functioning. The authors describe an experiment involving a novel cognitive task to point out the restrictive nature of the term 'executive capacity.' The chapter concludes by commenting briefly on the implications of a working memory model in which the executive does not play a major part.
Resumo:
We reported recently that bovine theca interna cells in primary culture express several type-I and type-II receptors for bone morphogenetic proteins (BMPs). The same cells express at least two potential ligands for these receptors (BMP-4 and - 7), whereas bovine granulosa cells and oocytes express BMP-6. Therefore, BMPs of intrafollicular origin may exert autocrine/paracrine actions to modulate theca cell function. Here we report that BMP-4, - 6, and - 7 potently suppress both basal ( P < 0.0001; respective IC50 values, 0.78, 0.30, and 1.50 ng/ml) and LH-induced ( P < 0.0001; respective IC50 values, 5.00, 0.55, and 4.55 ng/ml) androgen production by bovine theca cells while having only a moderate effect on progesterone production and cell number. Semiquantitative RT-PCR showed that all three BMPs markedly reduced steady-state levels of mRNA for P450c17. Levels of mRNA encoding steroidogenic acute regulatory protein, P450scc, and 3 beta-hydroxysteroid dehydrogenase were also reduced but to a much lesser extent. Immunocytochemistry confirmed a marked reduction in cellular content of P450c17 protein after BMP treatment ( P < 0.001). Exposure to BMPs led to cellular accumulation of phosphorylated Smad1, but not Smad2, confirming that the receptors signal via a Smad1 pathway. The specificity of the BMP response was further explored by coincubating cells with BMPs and several potential BMP antagonists, chordin, gremlin, and follistatin. Gremlin and chordin were found to be effective antagonists of BMP-4 and - 7, respectively, and the observation that both antagonists enhanced ( P < 0.01) androgen production in the absence of exogenous BMP suggests an autocrine/paracrine role for theca-derived BMP- 4 and - 7 in modulating androgen production. Collectively, these data indicate that an intrafollicular BMP signaling pathway contributes to the negative regulation of thecal androgen production and that ovarian hyperandrogenic dysfunction could be a result of a defective autoregulatory pathway involving thecal BMP signaling.
Resumo:
In this review we evaluate the cognitive and neural effects of positive and negative mood on executive function. Mild manipulations of negative mood appear to have little effect on cognitive control processes, whereas positive mood impairs aspects of updating, planning and switching. These cognitive effects may be linked to neurochemistry: with positive mood effects mediated by dopamine while negative mood effects may be mediated by serotonin levels. Current evidence on the effects of mood on regional brain activity during executive functions, indicates that the prefrontal cortex is a recurrent site of integration between mood and cognition. We conclude that there is a disparity between the importance of this topic and awareness of how mood affects, executive functions in the brain. Most behavioural and neuroimaging studies of executive function in normal samples do not explore the potential role of variations in mood, yet the evidence we outline indicates that even mild fluctuations in mood can have a significant influence on neural activation and cognition. (c) 2006 Elsevier Ltd. All rights reserved.
Resumo:
Individuals with fragile X syndrome (FXS) commonly display characteristics of social anxiety, including gaze aversion, increased time to initiate social interaction, and difficulty forming meaningful peer relationships. While neural correlates of face processing, an important component of social interaction, are altered in FXS, studies have not examined whether social anxiety in this population is related to higher cognitive processes, such as memory. This study aimed to determine whether the neural circuitry involved in face encoding was disrupted in individuals with FXS, and whether brain activity during face encoding was related to levels of social anxiety. A group of 11 individuals with FXS (5 M) and 11 age-and gender-matched control participants underwent fMRI scanning while performing a face encoding task with onlineeye-tracking. Results indicate that compared to the control group, individuals with FXS exhibited decreased activation of prefrontal regions associated with complex social cognition, including the medial and superior frontal cortex, during successful face encoding. Further, the FXS and control groups showed significantly different relationships between measures of social anxiety (including gaze-fixation) and brain activity during face encoding. These data indicate that social anxiety in FXS may be related to the inability to successfully recruit higher level social cognition regions during the initial phases of memory formation. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
This paper examines the pay-performance relationship between executive cash compensation (including bonuses) and company performance for a sample of large UK companies, focusing particularly on the financial services industry, since incentive misalignment has been blamed as one of the factors causing the global financial crisis of 2007–2008. Although we find that pay in the financial services sector is high, the cash-plus-bonus pay-performance sensitivity of financial firms is not significantly higher than in other sectors. Consequently, we conclude that it unlikely that incentive structures could be held responsible for inducing bank executives to focus on short-term results.
Resumo:
Increasingly, corporate occupiers seek more flexible ways of meeting their accommodation needs. One consequence of this process has been the growth of the executive suite, serviced office or business centre market. This paper, the final report of a research project funded by the Real Estate Research Institute, focuses upon the geographical distribution of business centers offering executive suites within the US. After a brief review of the development of the market, the paper examines the availability of data, provides basic descriptive statistics of the distribution of executive suites by state and by metropolitan statistical area and then attempts to model the distribution using demographic and socio-economic data at MSA level. The distribution reflects employment in key growth sectors and the position of the MSA in the urban hierarchy. An appendix presents a preliminary view of the global distribution of suites.
Resumo:
Purpose – The primary aim of this paper is to examine whether boards of directors with independent members function as effective corporate governance mechanisms in Chinese State-Owned Enterprises(SOEs), by analysing four characteristics of non-executive directors (NEDs) that impact on their effectiveness, namely their degree of independence, information, incentive, and competence. Design/methodology/approach – Being exploratory in nature, the research uses qualitative methods for data collection. It is based on an interpretivist perspective of social sciences, analysing and explaining the factors that influence the effectiveness of NEDs. Findings – The findings indicate that the NED system is weak in China as a result of the concentrated ownership structure, unique business culture, intervention of controlling shareholders and the lack of understanding of the benefits brought by NEDs. Research limitations/implications – The paper examines the salient features of and challenges to the system of NEDs of SOEs in present-day China. It provides an understanding of how the various perceptions of the board, gathered from in-depth interviews of corporate directors, leads to new interpretations of board effectiveness. The research, however, is limited owing to a relatively small sample size and the sensitive nature of the information collected. Originality/value – The study aims to fill gaps in the literature and contribute to it by assessing the “real” views and perceptions of NEDs in China in an institutional environment significantly different from that of the USA, the UK and other western economies.