The Effect Of Acute Psychological Stress Intensity On Attentional Functions

Stress often influences cognitive processes.At the neural level,acute psychological stress leads to increased activation in the occipital and parietal cortex and deactivation in the prefrontal cortex.Thus,acute psychological stress might affect cognitive processes that are supported by these brain regions.Attention is subserved by distinct neural networks serving the functions of alerting,orienting,and executive control function.These attentional networks involve activation of frontal and parietal sites,along with the lateral prefrontal cortex.However,whether and how acute psychological stress affects attentional function has not been investigated as yet.Some evidence suggests that acute psychological stress enhances attentional function,shortens response time,and improves task performance.However,other evidence suggests that acute psychological stress weakens attentional functions,increases response time,and impairs cognitive control.These divergent findings might be caused at least in some part by methodological differences such as the stress intensity of stressors,or selected different attention paradigms.Since different cognitive tasks were adopted in previous studies,the stress effects on the efficiency of attentional networks has not been measured simultaneously within one attentional task.The Attention Network Test(ANT)was designed to quantify the efficiency of the three networks at the behavioral level in the same individual at the same time.As recent studies have demonstrated,the N1 component may be involved in both alerting and orienting functions,whereas the P3 component is involved in executive control function.Experiment 1aims to explore the impact of mild acute psychological stress on the efficiency of three attentional functions and neural activity evoked by ANT.After stress was induced by a mental arithmetic task,Twenty-three college students were asked to complete the ANT.Record ECG signals throughout the experiment.Experiment 2 aims to investigate the effects of severe acute psychological stress on attentional functions.Forty-eight college students were randomly divided into stress group and control group.After stress was induced by the trier social stress test,participants were informed to complete the ANT.The results of experiment 1 were as follows,1)alerting and orienting effects resulted in enhanced parietal N1 and frontal P2 component in the stress blocks compared to the control blocks,suggesting that the alerting and orienting functions might be increased in the stress blocks;2)executive control effect resulted in larger P3 amplitude in the stress versus control blocks,reflecting an enhanced executive control process in the stress blocks.The results of experiment 2 were as follows,1)The N1 difference wave between the stress group and the control group was not significant,suggesting that alerting effect might not affected by stress;2)Compared with the control group,the amplitude of the P2 difference wave in the stress group increased,suggesting that the orienting functions might be increased in the stress group;3)Compared with the control group,the amplitude of the P3 difference wave in the stress group decreased,reflecting an decreased executive control process in the stress group.Taken together,these results suggest that mild acute psychological stress may increase alerting,orienting,and executive control functions of selective attention.However,the severe acute psychological stress might enhance orienting function,weaken executive control function,and has no significant effect on alerting function.