1,720,977 research outputs found
Calcium time series from OGB labeled V1 neurons in awake or anesthesized mice.
No full text<p>Calcium time series from OGB labeled V1 neurons in awake or anesthesized mice.</p>
<p>Data published in:</p>
<p>Pieter M. Goltstein, Jorrit S. Montijn, Cyriel M.A. Pennartz. (2015). Effects of isoflurane anesthesia on ensemble patterns of Ca2+ activity in mouse V1: Reduced direction selectivity independent of increased correlations in cellular activity. PLOS ONE.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Consciousness, Representation, Action: The Importance of Being Goal-Directed
No full textRecent years have witnessed fierce debates on the dependence of consciousness on interactions between a subject and the environment. Reviewing neuroscientific, computational, and clinical evidence, I will address three questions. First, does conscious experience necessarily depend on acute interactions between a subject and the environment? Second, does it depend on specific perception–action loops in the longer run? Third, which types of action does consciousness cohere with, if not with all of them? I argue that conscious contents do not necessarily depend on acute or long-term brain–environment interactions. Instead, consciousness is proposed to be specifically associated with, and subserve, deliberate, goal-directed behavior (GDB). Brain systems implied in conscious representation are highly connected to, but distinct from, neural substrates mediating GDB and declarative memory
Functional determinants of enhanced and depressed inter-areal information flow in NREM sleep between neuronal ensembles in rat cortex and hippocampus
No full textAbstractCompared to wakefulness, neuronal activity during non-REM sleep is characterized by a decreased ability to integrate information, but also by the re-emergence of task-related information patterns. To investigate the mechanisms underlying these seemingly opposing phenomena, we measured directed information flow by computing transfer entropy between neuronal spiking activity in three cortical regions and the hippocampus of rats across brain states. State-dependent information flow resulted to be jointly determined by the anatomical distance between neurons and by their functional specialization. We distinguished two regimes, operating at short and long time scales, respectively. From wakefulness to non-REM sleep, transfer entropy at short time scales increased for inter-areal connections between neurons showing behavioral task correlates. Conversely, transfer entropy at long time scales became stronger between non-task modulated neurons and weaker between task- modulated neurons. These results may explain how, during non-REM sleep, a global inter-areal disconnection is compatible with highly specific task-related information transfer.Author SummaryThe brain remains active during deep sleep, yet we still do not know which rules govern information processing between neurons across wakefulness and sleep. Here we provide a first study of how information flow at the level of spiking activity varies as a function of brain state, temporal scale, brain area and behavioral task correlates of single neurons. We found that inter-areal communication at millisecond time scales is enhanced during sleep compared to wakefulness between neurons that code for task information. Conversely, non-modulated neurons showed more prominent communication at longer time scales. These results indicate that multiple, functionally determined communicative architectures coexist in the brain, and provide a novel framework to understand information processing and its consequences during sleep.</jats:sec
Do intransitive choices reflect genuinely context-dependent preferences?
No full textA multitude of theories on decision making suppose that individuals choose between different prospects by placing a value, or utility, on these prospects and selecting whichever prospect has the highest value. If decisions were at all times value-based, then choices should always be transitive. Transitivity holds that, if prospect A is preferred over prospect B, and B is preferred over C, A should also be preferred over C. Despite its intuitive appeal, individuals often show striking violations of transitivity. Intransitive decisions could be the consequence of asymmetrically distributed errors made during the implementation of transitively organized values because individuals may be more likely to erroneously choose against their true preference when the discrimination between the prospects' values is difficult compared to situations where the prospect with the highest value is clearly and easily detectable. Alternatively, intransitive choices may reflect genuinely context-dependent preferences because individuals may compare the options' multiple attributes separately, not in an integrated fashion. This chapter replicates intransitive choices in a risky decision-making task, and presents a novel analysis that argues against the noisy implementation of transitive value account. It argues that choices reflect truly intransitive and context-dependent preferences, and discusses several possible explanations why individuals make decisions in such a way.<br/
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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