Long-distance neural synchrony correlates with processing strategies to compare fractions

Abstract

Adults use different processing strategies to work with fractions. Depending on task requirements, theymay analyze the fraction components separately (componential processing strategy, CPS) or consider thefraction as a whole (holistic processing strategy, HPS). It is so far unknown what is the brain coordinationdynamics underlying these types of fraction processing strategies. To elucidate this issue, we analyzedoscillatory brain activity during a fraction comparison task, presenting pairs of fractions either with orwithout common components. Results show that CPS induces a left frontal-parietal alpha phase desyn-chronization after the onset of fraction pairs, while HPS induces an increase of phase synchrony on thetaand gamma bands, over frontal and central-parietal sites, respectively. Additionally, the HPS evokes morenegative ERPs around 400 ms over the right frontal scalp than the CPS. This ERP activity correlates withthe increase of Theta phase synchrony. Our results reveal the emergence of different functional neuralnetworks depending on the kind of cognitive strategy used for processing fractions.