Transcranial direct current stimulation facilitates cognitive multi-task performance differentially depending on anode location and subtask.

Raja Parasuraman,Jon Strohl,Mahtab Alam,Marom Bikson,Melissa Scheldrup,Pamela M Greenwood,Ryan Mckendrick,R Andy Mckinley

doi:10.3389/fnhum.2014.00665

Abstract

There is a need to facilitate acquisition of real world cognitive multi-tasks that require long periods of training (e.g., air traffic control, intelligence analysis, medicine). Non-invasive brain stimulation—specifically transcranial Direct Current Stimulation (tDCS)—has promise as a method to speed multi-task training. We hypothesized that during acquisition of the complex multi-task Space Fortress, subtasks that require focused attention on ship control would benefit from tDCS aimed at the dorsal attention network while subtasks that require redirection of attention would benefit from tDCS aimed at the right hemisphere ventral attention network. We compared effects of 30 min prefrontal and parietal stimulation to right and left hemispheres on subtask performance during the first 45 min of training. The strongest effects both overall and for ship flying (control and velocity subtasks) were seen with a right parietal (C4, reference to left shoulder) montage, shown by modeling to induce an electric field that includes nodes in both dorsal and ventral attention networks. This is consistent with the re-orienting hypothesis that the ventral attention network is activated along with the dorsal attention network if a new, task-relevant event occurs while visuospatial attention is focused (Corbetta et al., 2008). No effects were seen with anodes over sites that stimulated only dorsal (C3) or only ventral (F10) attention networks. The speed subtask (update memory for symbols) benefited from an F9 anode over left prefrontal cortex. These results argue for development of tDCS as a training aid in real world settings where multi-tasking is critical.

Highlights

Many occupations of high importance to the nation require long periods of training on complex multi-tasks
No stimulation montage affected the points subtask. These findings suggest that initial learning of a complex multitask engages attention and working memory systems simultaneously, with these systems separately stimulated by specific transcranial Direct Current Stimulation (tDCS) montages
The present findings argue for development of tDCS as a training aid useful in real world settings where multi-tasking is critical

Summary

Introduction

Many occupations of high importance to the nation (e.g., air traffic control, intelligence analysis, medicine) require long periods of training on complex multi-tasks. Interest has turned to use of tDCS to facilitate acquisition of cognitive tasks that are quite complex and capture aspects of work or everyday environments, viz., decision-making (Fecteau et al, 2007; Boggio et al, 2010), driving a complex route (Beeli et al, 2008), military threat detection (Clark et al, 2012; Falcone et al, 2012), and air traffic control (Nelson et al, 2014). Such findings raise the prospect that tDCS could facilitate multitask training in real-world settings. There are several questions about use of tDCS with complex multi-tasks that need to be addressed

Methods

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Discussion

Conclusion