Neurocomputational Model of EEG Complexity during Mind Wandering.

Antonio J Ibáñez-Molina,Sergio Iglesias-Parro

doi:10.3389/fncom.2016.00020

Antonio J Ibáñez-Molina, Sergio Iglesias-Parro

Open Access

https://doi.org/10.3389/fncom.2016.00020

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Abstract

Mind wandering (MW) can be understood as a transient state in which attention drifts from an external task to internal self-generated thoughts. MW has been associated with the activation of the Default Mode Network (DMN). In addition, it has been shown that the activity of the DMN is anti-correlated with activation in brain networks related to the processing of external events (e.g., Salience network, SN). In this study, we present a mean field model based on weakly coupled Kuramoto oscillators. We simulated the oscillatory activity of the entire brain and explored the role of the interaction between the nodes from the DMN and SN in MW states. External stimulation was added to the network model in two opposite conditions. Stimuli could be presented when oscillators in the SN showed more internal coherence (synchrony) than in the DMN, or, on the contrary, when the coherence in the SN was lower than in the DMN. The resulting phases of the oscillators were analyzed and used to simulate EEG signals. Our results showed that the structural complexity from both simulated and real data was higher when the model was stimulated during periods in which DMN was more coherent than the SN. Overall, our results provided a plausible mechanistic explanation to MW as a state in which high coherence in the DMN partially suppresses the capacity of the system to process external stimuli.

Highlights

Mind wandering (MW) is a transient cognitive state in which conscious attention is decoupled from the external environment of an ongoing task in favor of focusing on intrinsic, self-generated thoughts or images
If we accept that external attention (EA) and MW are related to salience network (SN) and Default Mode Network (DMN), respectively, these findings suggest that transitions between EA and MW are characterized by changes in the general metastability of the cortex
It is accepted that EEG complexity can be related to the amount of underlying independent neural sources and, it can be sensitive to cortical synchrony. Their results indicated that the complexity of EEGs when participants were focused on the content of the videos was significantly lower for most recording sites than complexity of EEG series associated with a MW state. These results suggest that MW arises in the presence of a heterogeneous pattern of neural activation, and to what Hellyer et al (2014) found, it might indicate that the general cortical synchrony would be reduced, when compared with signals from externally generated thoughts

Summary

Introduction

Mind wandering (MW) is a transient cognitive state in which conscious attention is decoupled from the external environment of an ongoing task in favor of focusing on intrinsic, self-generated thoughts or images. This sensorial decoupling is associated with a reduction in the extent to which we process external events (Smallwood et al, 2008; Kam et al, 2010; Smilek et al, 2010; Hu et al, 2012; Mooneyham and Schooler, 2013). Despite important progress has been made, the underlying mechanism by which decoupled thoughts emerge has yet to be determined (Scott et al, 2015)

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