The Infraslow Frequency Oscillatory Transcranial Direct Current Stimulation Over the Left Dorsolateral Prefrontal Cortex Enhances Sustained Attention

Jingwen Qiao; Xinyu Li; Youhao Wang; Yifeng Wang; Gen Li; Ping Lu; Shouyan Wang

doi:10.3389/fnagi.2022.879006

The Infraslow Frequency Oscillatory Transcranial Direct Current Stimulation Over the Left Dorsolateral Prefrontal Cortex Enhances Sustained Attention

Front Aging Neurosci. 2022 Mar 30:14:879006. doi: 10.3389/fnagi.2022.879006. eCollection 2022.

Authors

Jingwen Qiao¹, Xinyu Li², Youhao Wang¹, Yifeng Wang³, Gen Li³, Ping Lu³, Shouyan Wang^{1

4}

Affiliations

¹ Academy for Engineering and Technology, Fudan University, Shanghai, China.
² Department of Electronic Engineering, Fudan University, Shanghai, China.
³ Institute of Brain and Psychological Sciences, Sichuan Normal University, Chengdu, China.
⁴ Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China.

Abstract

Background: The vigilance fluctuation and decrement of sustained attention have large detrimental consequences to most tasks in daily life, especially among the elderly. Non-invasive brain stimulations (e.g., transcranial direct current stimulation, tDCS) have been widely applied to improve sustained attention, however, with mixed results.

Objective: An infraslow frequency oscillatory tDCS approach was designed to improve sustained attention.

Methods: The infraslow frequency oscillatory tDCS (O-tDCS) over the left dorsolateral prefrontal cortex at 0.05 Hz was designed and compared with conventional tDCS (C-tDCS) to test whether this new protocol improves sustained attention more effectively. The sustained attention was evaluated by reaction time and accuracy.

Results: Compared with the C-tDCS and sham, the O-tDCS significantly enhanced sustained attention by increasing response accuracy, reducing response time, and its variability. These effects were predicted by the evoked oscillation of response time at the stimulation frequency.

Conclusion: Similar to previous studies, the modulation effect of C-tDCS on sustained attention is weak and unstable. In contrast, the O-tDCS effectively and systematically enhances sustained attention by optimizing vigilance fluctuation. The modulation effect of O-tDCS is probably driven by neural oscillations at the infraslow frequency range.

Keywords: infraslow frequency oscillatory tDCS; left dorsolateral prefrontal cortex; steady-state brain response; sustained attention; variability.