The Effects Of Long-term Academic Stress On Response Inhibition Of Non-emotional And Emotional Stimuli

Stress should be considered as a cognitive perception of uncontrollability and/or unpredictability that is expressed in a physiological and behavioral response.Long-term stress is usually a repetitive event that lasts for more than one month.Exposure to long-term and sustained stress has a variety of consequences on the brain,cognition and behavior.Among these consequences,long-term stress may lead to neuropsychiatric disorders in the prefrontal cortex,including depression,bipolar disorder,schizophrenia and anxiety disorders.Response inhibition ability to ensure individual selective attention task-related information to complete the goal-directed behavior and inhibit habitual response,which has been the ability to prove the existence of a close relationship with a variety of psychiatric disorders.Therefore,investigating the effect of long-term academic stress on response inhibition has important scientific and clinical significance.However,there is currently no study that directly investigates the cognitive neural mechanisms of long-term academic stress on response inhibition.In addition,the reasonable processing of emotional stimuli is of great significance to effectively cope with long-term academic stress and maintain physical and mental health.Therefore,this study explored the effects of long-term academic stress on the response inhibition of emotional and non-emotional stimuli through two experiments.Experiment 1 uses the event-related potential(ERP)technique to explore the effect of long-term academic stress on the response inhibition of non-emotional stimuli and its neural mechanism using a dual-task paradigm.The Beck Depression Inventory(BDI)and Life Events Scale(LES)were used to screen 35 postgraduate students who will take the National Postgraduate Entrance Exam(NPEE)in one month as the stress group,and 36 general college students as the control group to participate in the experiment.Long-term academic stress was assessed with Cohen' s Perceived Stress Scale(PSS,10-itemversion).Furthermore,participants emotional states and anxiety levels were assessed by the Positive and Negative Affect Scale(PANAS)and State-Trait Anxiety Inventory(STAI),respectively,after the participants arrived at the laboratory.The dual-task paradigm is to embed a probe task(single left or right arrow)after the classic Go/No Go paradigm,requiring the participants to judge the direction of the arrow after completing the Go/No Go task,and use the reaction time as a behavioral indicator of response inhibition.By comparing the similarities and differences in behaviors and neural activity of the students in the stress group and the control group in the dual-task paradigm,the effects of long-term academic stress on the ability of responseinhibition and their cognitive neural mechanisms were investigated.Experiment 2 selected 21 students preparing for NPEE as the stress group and 22 general college students as the control group.The questionnaires to be filled out after the participants arrive at the laboratory are consistent with Experiment 1.Use the emotional Go/No Go paradigm to explore the effect of long-term academic stress on the response inhibition of emotional stimulus.In this paradigm,select neutral and negative emotional pictures as stimuli,and add a pink or blue border to each picture to indicate separately.Participants performed key press response(Go)or response inhibition(No Go)after the stimulus appeared.By comparing the behavioral performance of the participants in the stress and control groups on the response inhibition of negative and neutral emotional stimuli,the role of emotion in the effects of long-term academic stress on response inhibition was explored.The results of this study found that,whether it was Experiment 1 or Experiment 2,the stress level,state anxiety,trait anxiety,and negative emotions of the stress group were significantly higher than those of the control group,indicating that preparing for the NPEE can indeed improve the level of stress.In Experiment 1,the behavioral results found that whether it was the stress group or the control group,the probe response time after Go stimulation was significantly shorter than that after No Go stimulation,indicating that the processing of No Go stimulation consumed more cognitive resources.For Go stimuli,Longer reaction time(RTs)were found for the control group.For the probe task,longer RTs were found for No Go-probe in the control group;RTs difference(No Go-Go)for the stress group were shouter than control group.These results indicate that participants under stress have a faster decision-making speed and less cognitive load,and long-term stress promotes the response suppression of non-emotional stimuli.For the Go/No Go task,greater No Go-P2 than Go-P2 was found for the both two group,shows that No Go processing requires more attention resources.Greater No Go-P3 than Go-P3 was found for the both two group,indicating that No Go induces a successful response inhibition than Go.The stress group showed increased P3 amplitude and No Go-probe P3 amplitude compared with the control group.It shows that when completing the dual-task paradigm,the participants in the stress group invested more cognitive resources than the participants in the control group,showed stronger response inhibition ability,and completed the target task more efficiently.In Experiment 2,the reaction time of the stress group to neutral and negative pictures was significantly shorter than that of the control group,indicating that long-term academic stress increased the alertness of the participants and accelerated the speed of information processing.The reaction time of the stress group to Go stimuli was significantly shorter than that of the control group,indicating that the participants in the stress group were more capable of identifying and performing emotional stimuli.The control group's response time to negative emotion pictures was significantly longer than that of neutral pictures,but the stress group showed no significant difference,which may indicate that long-term academic stress improved the individual's ability to detect,pay attention to and recognize emotional stimuli.