Synergistic Information Transfer in the Global System of Financial Markets.

Uncovering dynamic information flow between stock market indices has been the topic of several studies which exploited the notion of transfer entropy or Granger causality, its linear version. The output of the transfer entropy approach is a directed weighted graph measuring the information about the future state of each target provided by the knowledge of the state of each driving stock market index. In order to go beyond the pairwise description of the information flow, thus looking at higher order informational circuits, here we apply the partial information decomposition to triplets consisting of a pair of driving markets (belonging to America or Europe) and a target market in Asia. Our analysis, on daily data recorded during the years 2000 to 2019, allows the identification of the synergistic information that a pair of drivers carry about the target. By studying the influence of the closing returns of drivers on the subsequent overnight changes of target indexes, we find that (i) Korea, Tokyo, Hong Kong, and Singapore are, in order, the most influenced Asian markets; (ii) US indices SP500 and Russell are the strongest drivers with respect to the bivariate Granger causality; and (iii) concerning higher order effects, pairs of European and American stock market indices play a major role as the most synergetic three-variables circuits. Our results show that the Synergy, a proxy of higher order predictive information flow rooted in information theory, provides details that are complementary to those obtained from bivariate and global Granger causality, and can thus be used to get a better characterization of the global financial system.

Mapping attention during gameplay: Assessment of behavioral and ERP markers in an auditory oddball task.

Video games are enjoyed most when the level and speed of the game match the players' skills. An optimal balance between challenges and skills triggers the subjective experience of "flow," a focused motivation leading to a feeling of spontaneous joy. The present research investigates the behavioral and neural correlates of a paradigm aimed to assess the players' subjective experience during gameplay. Attentional engagement changes were assessed first at the behavioral level and in a second stage by means of EEG recordings. An auditory novelty oddball paradigm was implemented as a secondary task while subjects played in three conditions: boredom, frustration, and flow. We found higher reaction times and error rates in the flow condition. In a second stage, EEG time domain analysis revealed a significantly delayed response-locked frontocentral negative deflection during flow, likely signaling the reallocation of attentional resources. Source reconstruction analyses showed that the brain regions responsible for the genesis of this negativity were located within the medial frontal cortex. Frequency domain analyses showed a significant power increase only in the alpha band for the flow condition. Our results showed that this alpha power enhancement was correlated with faster reaction times. This suggests that frontal alpha changes recorded as maximal at the midfrontal lines during flow might be related to inhibitory top-down cognitive control processes.