181 research outputs found

    Beyond the Vestibulo-Ocular Reflex:Vestibular Input is Processed Centrally to Achieve Visual Stability

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    The current study presents a re-analysis of data from Zink et al. (1998, Electroencephalography and Clinical Neurophysiology, 107), who administered galvanic vestibular stimulation through unipolar direct current. They placed electrodes on each mastoid and applied either right or left anodal stimulation. Ocular torsion and visual tilt were measured under different stimulation intensities. New modelling introduced here demonstrates that directly proportional linear models fit reasonably well with the relationship between vestibular input and visual tilt, but not to that between vestibular input and ocular torsion. Instead, an exponential model characterised by a decreasing slope and an asymptote fitted best. These results demonstrate that in the results presented by Zink et al. (1998), ocular torsion could not completely account for visual tilt. This suggests that vestibular input is processed centrally to stabilise vision when ocular torsion is insufficient. Potential mechanisms and seemingly conflicting literature are discussed

    Tutorial: a priori estimation of sample size, effect size, and statistical power for cluster analysis, latent class analysis, and multivariate mixture models

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    Before embarking on data collection, researchers typically compute how many individual observations they should do. This is vital for doing studies with sufficient statistical power, and often a cornerstone in study pre-registrations and grant applications. For traditional statistical tests, one would typically determine an acceptable level of statistical power, (gu)estimate effect size, and then use both values to compute the required sample size. However, for analyses that identify subgroups, statistical power is harder to establish. Once sample size reaches a sufficient threshold, effect size is primarily determined by the number of measured features and the underlying subgroup separation. As a consequence, a priory computations of statistical power are notoriously complex. In this tutorial, I will provide a roadmap to determining sample size and effect size for analyses that identify subgroups. First, I introduce a procedure that allows researchers to formalise their expectations about effect sizes in their domain of choice, and use this to compute the minimally required number of measured variables. Next, I outline how to establish the minimum sample size in subgroup analyses. Finally, I use simulations to provide a reference table for the most popular subgroup analyses: k-means, Ward agglomerative hierarchical clustering, c-means fuzzy clustering, latent class analysis, latent profile analysis, and Gaussian mixture modelling. The table shows the minimum numbers of observations per expected subgroup (sample size) and features (measured variables) to achieve acceptable statistical power, and can be readily used in study design.Comment: Code and data: https://github.com/esdalmaijer/cluster_power_tutoria

    Cumulative culture spontaneously emerges in artificial navigators who are social and memory-guided

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    Cumulative cultural evolution occurs when adaptive innovations are passed down to consecutive generations through social learning. This process has shaped human technological innovation, but also occurs in non-human species. While it is traditionally argued that cumulative culture relies on high-fidelity social transmission and advanced cognitive skills, here I show that a much simpler system suffices. Cumulative culture spontaneously emerged in artificial agents who navigate with a minimal cognitive architecture of goal-direction, social proximity, and route memory. Within each generation, naive individuals benefitted from being paired with experienced navigators because they could follow previously established routes. Crucially, experienced navigators also benefitted from the presence of naive individuals through regression to the goal. As experienced agents followed their memorised path, their naive counterparts (unhindered by route memory) were more likely to err towards than away from the goal, and thus biased the pair in that direction. This improved route efficiency within each generation. In control experiments, cumulative culture was attenuated when agents' social proximity or route memory were lesioned, whereas eliminating goal-direction only reduced efficiency. These results demonstrate that cumulative cultural evolution occurs even in the absence of sophisticated communication or thought. One interpretation of this finding is that current definitions are too loose, and should be narrowed. An alternative conclusion is that rudimentary cumulative culture is an emergent property of systems that seek social proximity and have an imprecise memory capacity, providing a flexible complement to traditional evolutionary mechanisms.Comment: Code: https://github.com/esdalmaijer/artificial_navigators Data: https://doi.org/10.5281/zenodo.694418

    The Graded Fate of Unattended Stimulus Representations in Visuospatial Working Memory.

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    As in visual perception, information can be selected for prioritized processing at the expense of unattended representations in visual working memory (VWM). However, what is not clear is whether and how this prioritization degrades the unattended representations. We addressed two hypotheses. First, the representational quality of unattended items could be degraded as a function of the spatial distance to attended information in VWM. Second, the strength with which an item is bound to its location is degraded as a function of the spatial distance to attended information in VWM. To disentangle these possibilities, we designed an experiment in which participants performed a continuous production task in which they memorized a visual array with colored discs, one of which was spatially retro-cued, informing the target location of an impending probe that was to be recalled (Experiment 1). We systematically varied the spatial distance between the cued and probed locations and obtained model-based estimates of the representational quality and binding strengths at varying cue-probe distances. Although the representational quality of the unattended representations remained unaffected by the cue-probe distance, spatially graded binding strengths were observed, as reflected in more spatial confusions at smaller cue-probe distances. These graded binding strengths were further replicated with a model-free approach in a categorical version of the production task in which stimuli and responses consisted of easily discriminable colors (Experiment 2). These results demonstrate that unattended representations are prone to spatial confusions due to spatial degradation of binding strengths in WM, even though they are stored with the same representational quality

    Моральна свідомість та релігійна віра в перспективі філософії Іммануїла Канта

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    У статті розкриваються головні ідеї та логічна структура філософії релігії Іммануїла Канта у її зв’язку з практичною філософією. Обґрунтовано тезу про те, що розуміння Кантом головних релігійних ідей – особистого безсмертя та Бога − було дуже неортодоксальним і наближає його філософію до індійської релігійно-філософської традиції.В статье раскрываются главные идеи и логическая структура философии религии Иммануила Канта в связи с его практической философией. Обосновывается тезис о том, что понимание Кантом главных религиозных идей – личного бессмертия и Бога − было очень неортодоксальным и сближает его философию с индийской религиозно-философской традицией.The article explains main ideas and logical structure of Immanuel Kant’s philosophy of religion in its connection with practical philosophy. It argues that Kant’s views of main religious ideas – personal immortality and God − were very unorthodox and congenial with Indian religious-philosophical tradition

    Forever yuck: Oculomotor avoidance of disgusting stimuli resists habituation.

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    Disgust is an adaptation forged under the selective pressure of pathogens. Yet disgust may cause problems in contemporary societies because of its propensity for "false positives" and resistance to corrective information. Here, we investigate whether disgust, as revealed by oculomotor avoidance, might be reduced through the noncognitive process of habituation. In each of three experiments, we repeatedly exposed participants to the same pair of images, one disgusting and one neutral, and recorded gaze. Experiment 1 (N = 104) found no decline in oculomotor avoidance of the disgusting image after 24 prolonged exposures. Experiment 2 (N = 99) replicated this effect and demonstrated its uniqueness to disgust. In Experiment 3 (N = 93), we provided a gaze-contingent reward to ensure perceptual contact with the disgusting image. Participants looked almost exclusively at the disgusting image for 5 min but resumed baseline levels of oculomotor avoidance once the reward ceased. These findings underscore the challenge of reducing disgust. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

    Banana for scale: Gauging trends in academic interest by normalising publication rates to common and innocuous keywords

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    Many academics use yearly publication numbers to quantify academic interest for their research topic. While such visualisations are ubiquitous in grant applications, manuscript introductions, and review articles, they fail to account for the rapid growth in scientific publications. As a result, any search term will likely show an increase in supposed "academic interest". One proposed solution is to normalise yearly publication rates by field size, but this is arduous and difficult. Here, we propose an simpler index that normalises keywords of interest by a ubiquitous and innocuous keyword, such as "banana". Alternatively, one could opt for field-specific keywords or hierarchical structures (e.g. PubMed's Medical Subject Headings, MeSH) to compute "interest market share". Using this approach, we uncovered plausible trends in academic interest in examples from the medical literature. In neuroimaging, we found that not the supplementary motor area (as was previously claimed), but the prefrontal cortex is the most interesting part of the brain. In cancer research, we found a contemporary preference for cancers with high prevalence and clinical severity, and notable declines in interest for more treatable or likely benign neoplasms. Finally, we found that interest in respiratory viral infections spiked when strains showed potential for pandemic involvement, with SARS-CoV-2 and the COVID-19 pandemic being the most extreme example. In sum, the time is ripe for a quick and easy method to quantify trends in academic interest for anecdotal purposes. We provide such a method, along with software for researchers looking to implement it in their own writing.Comment: The software described in this manuscript can be found on https://github.com/esdalmaijer/bibliobanan

    П.А. Столыпин и развитие сельской кредитной кооперации в дореволюционной России

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    Цель статьи - рассмотрение аграрной реформы П.А. Столыпина в контексте развития в дореволюционной России сельской кредитной кооперации
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