465 research outputs found
Reply to "Comment on `Performance of different synchronization measures in real data: A case study on electroencephalographic signals'"
We agree with the Comment by Nicolaou and Nasuto about the utility of mutual information (MI) when properly estimated and we also concur with their view that the estimation based on k nearest neighbors gives optimal results. However, we claim that embedding parameters can indeed change MI results, as we show for the electroencephalogram data sets of our original study and for coupled chaotic systems. Furthermore, we show that proper embedding can actually improve the estimation of MI with the k nearest neighbors algorithm
Ethics in the Suburbs: An Exegesis of the film The King of Frankston
This study outlines and examines three prominent ethical concerns in the short documentary ‘The King of Frankston’
Latency and Selectivity of Single Neurons Indicate Hierarchical Processing in the Human Medial Temporal Lobe
Neurons in the temporal lobe of both monkeys and humans show selective responses to classes of visual stimuli and even to specific individuals. In this study, we investigate the latency and selectivity of visually responsive neurons recorded from microelectrodes in the parahippocampal cortex, entorhinal cortex, hippocampus, and amygdala of human subjects during a visual object presentation task. During 96 experimental sessions in 35 subjects, we recorded from a total of 3278 neurons. Of these units, 398 responded selectively to one or more of the presented stimuli. Mean response latencies were substantially larger than those reported in monkeys. We observed a highly significant correlation between the latency and the selectivity of these neurons: the longer the latency the greater the selectivity. Particularly, parahippocampal neurons were found to respond significantly earlier and less selectively than those in the other three regions. Regional analysis showed significant correlations between latency and selectivity within the parahippocampal cortex, entorhinal cortex, and hippocampus, but not within the amygdala. The later and more selective responses tended to be generated by cells with sparse baseline firing rates and vice versa. Our results provide direct evidence for hierarchical processing of sensory information at the interface between the visual pathway and the limbic system, by which increasingly refined and specific representations of stimulus identity are generated over time along the anatomic pathways of the medial temporal lobe
On a comparative study between dependence scales determined by linear and non-linear measures
In this manuscript we present a comparative study about the determination of
the relaxation (\textit{i.e.}, independence) time scales obtained from the
correlation function, the mutual information, and a criterion based on the
evaluation of a nonextensive generalisation of mutual entropy. Our results show
that, for systems with a small degree of complexity, standard mutual
information and the criterion based on its nonextensive generalisation provide
the same scale, whereas for systems with a higher complex dynamics the standard
mutual information presents a time scale consistently smaller.Comment: 14 pages. To appear in Physica
Independent components in spectroscopic analysis of complex mixtures
We applied two methods of "blind" spectral decomposition (MILCA and SNICA) to
quantitative and qualitative analysis of UV absorption spectra of several
non-trivial mixture types. Both methods use the concept of statistical
independence and aim at the reconstruction of minimally dependent components
from a linear mixture. We examined mixtures of major ecotoxicants (aromatic and
polyaromatic hydrocarbons), amino acids and complex mixtures of vitamins in a
veterinary drug. Both MICLA and SNICA were able to recover concentrations and
individual spectra with minimal errors comparable with instrumental noise. In
most cases their performance was similar to or better than that of other
chemometric methods such as MCR-ALS, SIMPLISMA, RADICAL, JADE and FastICA.
These results suggest that the ICA methods used in this study are suitable for
real life applications. Data used in this paper along with simple matlab codes
to reproduce paper figures can be found at
http://www.klab.caltech.edu/~kraskov/MILCA/spectraComment: 22 pages, 4 tables, 6 figure
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