High-frequency Repetitive Transcranial Magnetic Stimulation over the Left Dorsolateral Prefrontal Cortex Can Improve Attentional Control Under Stress: Behavioral and Electrophysiological Evidence.

Abstract

Psychological stress impairs cognition, forcing attention toward stressor-related information. However, stress may reallocate limited cognitive resources in adaptive ways. How stress modulates the attentional control remains unclear. In this study, the stress-related changes in both target processing and distractor interference were investigated in Experiment 1, where an additional singleton task was employed with a stress group and a control group. The left dorsolateral prefrontal cortex (DLPFC) has been associated with both stress responses and attentional control. The role of the left DLPFC in regulating attention control under stress was investigated using repetitive TMS in Experiment 2, which included control-vertex, stress-vertex, and stress-DLPFC groups. Electroencephalography was recorded. The results showed that, (1) the stress/stress-vertex group exhibited increased RT attentional capture effect and greater distractor-elicited N2pc effect compared with the control/control-vertex group, indicating increased distractor interference under stress. (2) The stress/stress-vertex group exhibited a greater target-elicited N2pc effect compared with the control/control-vertex group, suggesting enhanced target processing under stress. (3) Compared with the stress-vertex group, the stress-DLPFC group exhibited greater target-elicited N2pc effect, but a similar distractor-elicited N2pc effect, suggesting that left-DLPFC stimulation improved target processing but exerted no influence on distractor processing. In addition, faster RTs, along with a reduced RT attentional capture effect, were found for the stress-DLPFC group, implying that the target processing following left-DLPFC stimulation might be less affected by the distractor due to the heightened target processing. The left DLPFC may play a crucial role in modulating attentional control under stress.