Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Scale-free brain functional networks   Functional magnetic resonance imaging (fMRI) is used to extract {\em
functional networks} connecting correlated human brain sites. Analysis of the
resulting networks in different tasks shows that: (a) the distribution of
functional connections, and the probability of finding a link vs. distance are
both scale-free, (b) the characteristic path length is small and comparable
with those of equivalent random networks, and (c) the clustering coefficient is
orders of magnitude larger than those of equivalent random networks. All these
properties, typical of scale-free small world networks, reflect important
functional information about brain states.

7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
16
The categories of this paper are: stat