A Study Based On The Effect Of 2D/3D Vision-induced Fear Stress On Brain Cognitive Function

BackgroundFear stress is an unavoidable part of military operations.Well-cooperation with fear stress events is an important factor to maintain high task execution ability in high-risk situations.It is of great military significance to investigate how the critical situation affects the task execution ability of military operators,in order to evaluate and early warn the cognitive impairment in high-risk conditions,and to select and train the individuals who can still maintain good cognitive function in the state of fear stress.In the past,the methods of inducing fear stress under laboratory conditions were limited and could not meet the military needs.3D immersive film technology can improve the participants' sense of presence and immersion and make people feel immersed in a surreal world.Asides from that,the highly programmability and scalability make it suitable for the study of executive function changes induced by fear stress with high ecological validity.Objective3D immersion fear stress induction was used to investigate the effect of fear stress on cognitive function,extract the neurophysiological characteristics after fear stress,and compare with the effect of 2D visual fear stress induction commonly used in the laboratory.MethodA self-control design was used to study the effects of fear stress induced by different ways on executive function and salience processing function through 3D visual evoked fear stress and 2D visual evoked fear stress.Region of interest based esting state f MRI functional connectivity analysis,EEG power spectrum analysis,Granger causality analysis,event-related potential analysis and traceability analysis were used.Result1.Effect of fear stress on EEG power spectrum of spontaneous brain activityThe change of EEG power spectrum was selected as the index of fear stress affecting cognitive function.The results showed that:(1)fear stress increased the oscillations of slow wave(? and ?)and weakened the oscillations of fast wave(?,? and ?);(2)under the condition of 3D visual evoked fear stress,the right side of ? band was more obvious around parietal areas;(3)the increase of slow wave oscillation and the decrease of fast wave oscillation were more significant under the condition of 3D visual evoked fear stress.2.The effect of fear stress on the functional connection of insular leafAs a critical hub of the salience network,the right anterior insula(r AI)is a causal node that switches the brain from the default network activation to the central execution network under task condition.The r AI-based f MRI functional connectivity analysis was used to study the changes of the functional connectivity of the r AI after 2D horror films.Then the functional network from f MRI was introduced into EEG source imaging as spatial prior information,and the Granger causal connection between the r AI and other brain regions was analyzed under different stress-induced modes.f MRI results showed that:(1)the functional connectivity between the r AI and key nodes in the frontal executive network was weakened after fear stress,and the functional connection with salient information processing brain area was enhanced;(2)the functional connectivity between the r AI and the orbital frontal cortex and the temporal middle gyrus was weakened after fear stress;the EEG results showed that:(3)The information transmission from dl PFC and IPL to the r AI is enhanced under 3D visual induced fear stress,and the two-way information transmission between r AI and postcentral gyrus is also enhanced.3.The impact of fear stress on executive functionThe Stroop task was used to study the effects of 2D visually induced fear stress and3 D visually induced fear stress on executive functions.The results found that:(1)the Stroop task performance was significantly impaired after 3D visually induced fear stress;(2)the 3D visually induced fear stress leads to a greater difference in the ERP amplitude between the color word inconsistent trials and the color word consistent trials;(3)When performing the color word conflict task after 3D visually induced fear stress,the synchronization of neuronal activity in the ? band of the cuneus,posterior central gyrus and parahippocampal gyrus increased,and the ? band synchronization increases in the cuneus and the medial frontal gyrus;(4)When performing color word conflict tasks after3 D visually induced fear stress,the increase in the synchronization of high-frequency components(? and ?)of neuron firing starts at 100 ms after the presentation of the stimulus,and the increase in the synchronicity of low-frequency components(? and ?))of neuronal firing starts 400 ms after the presentation of the stimulus.ConclusionCompared with 2D visually evoked fear stress,3D visually evoked fear stress has a lower power spectrum in the fast-wave frequency band and higher power spectrum in the slow-wave frequency band.The main brain areas of the executive network have enhanced information transmission to r AI and sensory processing.The two-way information transmission between sensory processing brain area and r AI is enhanced.Task state data shows that the performance of Stroop task is worse after 3D visual evoked fear stress.The neuron firing in sensory information processing area caused by Stroop effect is more consistent,and the power of EEG frequency band related to cognitive load is increased while the power of the EEG frequency band related to the processing of irrelevant information is reduced.The results show that the brain function changes caused by 3D visual fear stress are more obvious than 2D visually induced fear stress.In addition,after fear stress,the functional connection between the right anterior insula and key nodes in the frontal parietal executive network is weakened,the functional connection with the orbitofrontal cortex and the middle temporal gyrus is weakened,and the functional connection with the sensory information processing brain area is strengthened.The results show that fear stress leads to increased sensory processing and decreased executive function.