An ERP Study On The Spatial And Temporal Characteristics Of Selective Attention Of University Students With High Suicidal Ideation

In recent years,the phenomenon of suicide among university students has aroused great concern in society and schools.Suicide has become the second leading cause of death among university students,according to research.It is found that suicidal individuals cannot make correct evaluation and value judgment on external events,and their feelings and experiences of external living environment are closely related to prejudice,so they are more likely to have suicidal thoughts,namely,suicidal ideation.Selective attention to threatening external stimuli is the first gateway to suicidal ideation.It is important to explore the selective attention of suicidal ideators,which can provide more support for the mechanism of suicidal ideation and suicide intervention programs.The selectivity of attention means that individuals choose one of two or more stimuli to pay attention while ignoring the other.Attentional bias and attentional blink are individuals’ selective attention to spatially presented stimuli and time series presented stimuli,respectively.The purpose of this study was to investigate whether university students with high suicidal ideation have selective attention to negative stimuli and its characteristics.Therefore,this study intends to use high temporal resolution event-related potential technology to explore the selective attention of suicidal ideation university students to negative stimuli,so as to provide more clues to the emotional bias mechanism of suicidal ideation university students and suicide intervention programs.Study 1 started from the perspective of spatial selective attention bias,using dot-probe paradigm to investigate the attention bias of the suicidal ideation university students on negative emotional faces.There are two groups,named control group and high suicidal ideation group.The participants of two groups need to finish dot-probe tasks with neutral-neutral face pairs,neutral-positive face pairs and neutral-sad face pairs as the prompt message.The results showed that the neutral-sad faces had alarger P2 amplitude in the group with the highest levels of suicidal ideation,compared with the control group’s students.And in addition,the neutral-sad face pairs induced greater P3 amplitude in the group with high suicidal ideation than the neutral-positive face pairs.Study 2 started from the perspective of time selective attention bias,using rapid serial visual presentation paradigm to investigate the attention blink mechanism of university students with suicidal ideation.The participants of two groups need to finish the task of rapid serial visual presentation with negative faces,negative environment,neutral faces and neutral environment as T1,and rotating unrelated landscape scenery as T2.The results showed that the environmental N3 amplitude of the subjects in the control group was larger than that of the faces.But the N3 amplitude of the faces in the suicidal ideation group was greater than the N3 amplitude of the environment.Conclusions: 1)University students with high suicidal ideation have disengagement difficulty to negative emotional stimuli in the late stage of cognitive processing in both temporal and spatial selective attention;2)In the early stage of cognitive processing,spatial selective attention is also manifested as attention vigilance to negative emotional stimuli.