435 research outputs found

    The role of working memory in carrying and borrowing

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    The present study analyzed the role of phonological and executive components of working memory in the borrow operation in complex subtractions (Experiments 1 and 2) and in the carry operation in complex multiplications (Experiments 3 and 4). The number of carry and borrow operations as well as the value of the carry were manipulated. Results indicated that both the number of carry/borrow operations and the value of the carry increased problem difficulty, resulting in higher reliance on phonological and executive working-memory components. Present results are compared with those obtained for the carry operation in complex addition and are further discussed in the broader framework of working-memory functions

    Influence of pathogenic stimuli on Müller cell transfection by lipoplexes

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    Neuroprotection is a mutation-independent therapeutic strategy that seeks to enhance the survival of neuronal cell types through delivery of neuroprotective factors. The Willer cell, a retinal glial cell type appreciated for its unique morphology and neuroprotective functions, could be regarded as an ideal target for this strategy by functioning as a secretion platform within the retina following uptake of a transgene of our choice. In this in vitro study we aimed to investigate the capability of Willer cells to take up a standard liposomal vector (i.e. Lipofectamine 2000) and process its pDNA or mRNA cargo into the reporter GFP protein. By doing so, we found that mRNA outperformed pDNA in Willer cell transfection efficiency. Since neuroprotection is explored as a therapy for diabetic retinopathy and glaucoma, we furthermore examined the Willer cell's lipoplex-induced transfection efficiency and cytotoxicity in stressful conditions linked to these diseases - i.e. hypoxia, hyperglycemia and oxidative stress. Interestingly, Willer cells were able of maintaining high GFP expression regardless of these noxious stimuli. In terms of lipoplex-induced toxicity, hyperglycemia seemed to have a protective effect while hypoxia and oxidative stress led to a slightly higher toxicity. In conclusion, our study indicates that mRNA-lipoplexes have potential in transfecting Willer cells in healthy as well as diseased conditions

    Where to attend next: guiding refreshing of visual, spatial, and verbal representations in working memory

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    One of the functions that attention may serve in working memory (WM) is boosting information accessibility, a mechanism known as attentional refreshing. Refreshing is assumed to be a domain-general process operating on visual, spatial, and verbal representations alike. So far, few studies have directly manipulated refreshing of individual WM representations to measure the WM benefits of refreshing. Recently, a guided-refreshing method was developed, which consists of presenting cues during the retention interval of a WM task to instruct people to refresh (i.e., attend to) the cued items. Using a continuous-color reconstruction task, previous studies demonstrated that the error in reporting a color varies linearly with the frequency with which it was refreshed. Here, we extend this approach to assess the WM benefits of refreshing different representation types, from colors to spatial locations and words. Across six experiments, we show that refreshing frequency modulates performance in all stimulus domains in accordance with the tenet that refreshing is a domain-general process in WM. The benefits of refreshing were, however, larger for visual-spatial than verbal materials

    Tournament incentives and corporate fraud

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    This paper identifies a new incentive for managers to engage in corporate fraud stemming from the relative performance evaluation feature of CEO promotion tournaments. We document higher propensities to engage in fraud for firms with strong tournament incentives (as proxied for by the CEO pay gap). We posit that the relative performance evaluation feature of CEO promotion tournaments creates incentives to manipulate performance, while the option-like character can motivate managers to engage in risky activities. We thereby extend previous corporate fraud literature that focuses mainly on equity-based incentives and reports mixed findings. Our results are robust to using different fraud samples, and controlling for other known determinants of fraud as well as manager skills

    An examination of refreshing in between-category sequences

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    The present study focused on refreshing within a working memory (WM) context. Refreshing refers to the mechanism that brings back information into the focus of attention in order to counteract forgetting of memory traces. Despite some research on this topic, the exact nature of refreshing remains unclear. The present study investigated refreshing by means of the cognitive load (CL) effect. This effect is typically observed in complex span tasks, which combine processing and storage demands. It refers to the observation that WM performance depends on the CL of concurrent processing, defined as the proportion of time between list items that is occupied by concurrent processing and therefore not available to refresh memory items. Traditionally, the CL effect has been demonstrated using within-category memory sequences in which all memory items are drawn from one category (e.g., all words). Here, we show that the CL effect also applies to between-category memory sequences in which memory items are drawn from different categories (e.g., words, orientations, faces, etc.). The ensemble of the results adds to the domain-generality of the CL effect. Implications concerning the specific nature of refreshing and future research directions are discussed

    A common short-term memory retrieval rate may describe many cognitive procedures

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    We examine the relationship between response speed and the number of items in short-term memory (STM) in four different paradigms and find evidence for a similar high-speed processing rate of about 25–30 items per second (∼35–40 ms/item). We propose that the similarity of the processing rates across paradigms reflects the operation of a very basic covert memory process, high-speed retrieval, that is involved in both the search for information in STM and the reactivation or refreshing of information that keeps it in STM. We link this process to a specific pattern of rhythmic, repetitive neural activity in the brain (gamma oscillations). This proposal generates ideas for research and calls for an integrative approach that combines neuroscientific measures with behavioral cognitive techniques
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