HD-tDCS mitigates the executive vigilance decrement only under high cognitive demands

Abstract

Maintaining vigilance is essential for many everyday tasks, but over time, our ability to sustain it inevitably decreases, potentially entailing severe consequences. High-definition transcranial direct current stimulation (HD-tDCS) has proven to be useful for studying and improving vigilance. This study explores if/how cognitive load affects the mitigatory effects of HD-tDCS on the vigilance decrement. Participants (N = 120) completed a modified ANTI-Vea task (single or dual load) while receiving either sham or anodal HD-tDCS over the right posterior parietal cortex (rPPC). This data was compared with data from prior studies (N = 120), where participants completed the standard ANTI-Vea task (triple load task), combined with the same HD-tDCS protocol. Against our hypotheses, both the single and dual load conditions showed a significant executive vigilance (EV) decrement, which was not affected by the application of rPPC HD-tDCS. On the contrary, the most cognitively demanding task (triple task) showed the greatest EV decrement; importantly, it was also with the triple task that a significant mitigatory effect of the HD-tDCS intervention was observed. The present study contributes to a more nuanced understanding of the specific effects of HD-tDCS on the vigilance decrement considering cognitive demands. This can ultimately contribute to reconciling heterogeneous effects observed in past research and fine-tuning its future clinical application.

Can transcutaneous auricular vagus nerve stimulation mitigate vigilance loss? Examining the effects of stimulation at individualized vs. constant current intensity

“…Dissociable patterns at the behavioral (Luna, Barttfeld, et al, 2022;Luna, Tortajada, et al, 2022;Román-Caballero et al, 2021), physiological (Feltmate et al, 2020;Sanchis et al, 2020;Sanchis-Navarro et al, 2024), and neural (Hemmerich et al, 2023(Hemmerich et al, , 2024Luna et al, 2020Luna et al, , 2023bLuna et al, , 2023a levels were observed for EV and AV when measuring vigilance components via the ANTI-Vea task. Most importantly, the EV and AV decrements were independently mitigated by stimulating different mechanisms of sustained attention.…”