Modulation of executive attention and decision-making using transcranial Direct Current Stimulation (tDCS): a double-blind sham-controlled study

Successful behaviour depends on the ability to focus resources on goal-relevant information while filtering out, or inhibiting, irrelevant information. Indeed, a core feature of flexible and adaptive behaviour is the ability to override an automatic propensity to respond in a given situation, while performing an unnatural, but advantageous response. In particular, decision-making is characterized by a careful balance of oppositely-valenced drives, such as gains versus losses or sure versus probabilistic outcomes, resulting in a general preference for avoiding losses over acquiring equivalent gains (loss aversion) and for sure over risky outcomes (risk aversion). Starting from this assumption, the aim of the study is to investigate the impact of the High-Definition transcranial Direct Current Stimulation (HD-tDCS) of the dorsal Anterior Cingulate Cortex (dACC) both on executive attention via the Flanker task, and on risk- and loss-aversion with two gambling tasks. Alongside a marginal effect on risk aversion, the cathodal stimulation of dACC was found to elicit a significant improvement of executive attention, as tracked by a decreased “conflict effect” at the Flanker task. Even though the actual mechanisms and outcome of tDCS are debated, dACC – which has been consistently associated with cognitive dysfunctions in several neuro-psychiatric disorders, represents an ideal target for neurostimulation treatment protocols, The present results provide preliminary evidence of the capabilities of tDC of dACC, highlighting possible applications in brain diseases involving executive attention, decision-making inhibitory control, such as addictions.