Core-periphery organization of brain dynamics during learning.

<p>The relationship between temporal and geometrical core-periphery organization and their associations with learning are present in individual subjects. We represent this relationship using spirals in a plane; data points in this plane represent brain regions located at the polar coordinates (, ), where is the flexibility of the region, is the skewness of flexibility over all regions, and is the learning parameter (see the <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003171#s4" target="_blank">Materials and Methods</a>) that describes each individual's relative improvement between sessions. The skewness predicts individual differences in learning; the Spearman rank correlation is and . Poor learners (straighter spirals) tend to have a low skewness (short spirals), whereas good learners (curvier spirals) tend to have high skewness (long spirals). Color indicates flexibility: blue nodes have lower flexibility, and brown nodes have higher flexibility.