Authors: Jun Kitazono,Ryota Kanai,Masafumi Oizumi
ArXiv: 1712.06745
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Abstract URL: http://arxiv.org/abs/1712.06745v2
The ability to integrate information in the brain is considered to be an
essential property for cognition and consciousness. Integrated Information
Theory (IIT) hypothesizes that the amount of integrated information ($\Phi$) in
the brain is related to the level of consciousness. IIT proposes that to
quantify information integration in a system as a whole, integrated information
should be measured across the partition of the system at which information loss
caused by partitioning is minimized, called the Minimum Information Partition
(MIP). The computational cost for exhaustively searching for the MIP grows
exponentially with system size, making it difficult to apply IIT to real neural
data. It has been previously shown that if a measure of $\Phi$ satisfies a
mathematical property, submodularity, the MIP can be found in a polynomial
order by an optimization algorithm. However, although the first version of
$\Phi$ is submodular, the later versions are not. In this study, we empirically
explore to what extent the algorithm can be applied to the non-submodular
measures of $\Phi$ by evaluating the accuracy of the algorithm in simulated
data and real neural data. We find that the algorithm identifies the MIP in a
nearly perfect manner even for the non-submodular measures. Our results show
that the algorithm allows us to measure $\Phi$ in large systems within a
practical amount of time.