1,721,004 research outputs found
Identity Assurance through EEG Recordings
No full textThe problem of identity assurance, i.e. determining if a claimed identity can be trusted, has been gaining relevance in the last decade, due to the increasing use of on-line services. While this trend can be seen for many biometric sensors, very few studies have considered the use of brain electric signals. This contribution proposes a first solution, based on the reconstruction of motifs (patterns of connectivity between three electroencephalographic sensors) and on the assessment of their stability across different trials for a single subject. Results indicate that, although computationally costly, this approach is promising in terms of the classification scores obtained
Does the brain behave like a (complex) network? I. Dynamics.
No full textGraph theory is now becoming a standard tool in system-level neuroscience. However, endowing
observed brain anatomy and dynamics with a complex network structure does not entail that the
brain actually works as a network. Asking whether the brain behaves as a network means asking
whether network properties count. From the viewpoint of neurophysiology and, possibly, of brain
physics, the most substantial issues a network structure may be instrumental in addressing relate
to the influence of network properties on brain dynamics and to whether these properties ultimately
explain
some
aspects
of
brain
function.
Here,
we
address
the
dynamical
implications
of
complex
network, examining which aspects and scales of brain activity may be understood to
genuinely behave as a network. To do so, we first define the meaning of networkness, and analyse
some of its implications. We then examine ways in which brain anatomy and dynamics can be
endowed with a network structure and discuss possible ways in which network structure may be
shown to represent a genuine organisational principle of brain activity, rather than just a
convenient description of its anatomy and dynamics
Network Theory in Neuroscience
No full textNetwork theory is a branch of mathematics concerned with the analysis of the structure of graphs,
the mathematical abstraction of networks. Since the beginning of the twenty-first century, it has
become an applied discipline due to the availability of large datasets for social, technological, and
biological systems. Although network theory was initially restricted to topological analysis, it has
soon become a tool for understanding the emergence, functioning, and evolution of networks and the
dynamical processes occurring on them. The application of network theory to neuroscience and,
more specifically, to the analysis of brain structure and function represents a qualitatively different
view of brain activity and brain-behavior mapping, shifting from a computerlike to a complex
system vision of the brain, where networks are endowed with properties which stem in a nontrivial
way from those of their constituent nodes. The network approach allows addressing an entirely new
set of issues, such as detection and description of modularity and hierarchical structure, evaluation of
efficiency and vulnerability, and structure-function relationships in healthy brains and disease
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
Editorial: Advances in brain dynamics in the healthy and psychiatric disorders
No full textPsychiatry aims at diagnosing and treating psychological disorders and other mental health conditions affecting how subjects behave, think, or feel. Psychiatrists resort to a variety of diagnostic techniques, ranging from standard semiotics to physiological testing, and imaging or stimulation techniques, and treatment strategies may be behavioral, pharmacological, or instrumental. However, knowledge of how neural activity translates into behavior is often insufficient to define precise nosological categories and to interact with the brain in a language it can understand. Improvements in both modeling and treatment require a better understanding of the underlying neural processes and finding new meaningful variables to characterize both healthy brain activity and its pathology
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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