Brain Activity Of Cognitive Reappraisal By TMS-EEG Co-registration

The ability of cognitive emotion regulation directly affects individual mental state and social behavior.Emotional disorders are the core problem of many mental illnesses.Cognitive reappraisal,one strategy of emotion regulation,aims to reinterpret the emotional meaning of the stimulus in order to change the response to emotional stimulus.This strategy is considered as the most effective one,so that be concerned by many researchers.Studies show that cognitive reappraisal has two important characteristics,whose temporally dynamical characteristic and spatially interacted with widespread brain regions.Cognitive reappraisal is complicated and diverse,containing various tactics to reappraisal.Different brain regions are engaged in cognitive control process of these tactics.Also,they have different temporal characteristics.In the past few decades,a large number of studies have pointed out that the prefrontal network plays an critical role in cognitive reappraisal.However,there is still a lack of evidence on causality of regions included in the prefrontal network in cognitive reappraisal.Moreover,it remains unclear in terms of the temporal and spatial dynamics of the specific tactic of cognitive reappraisal.Therefore,it is necessary to figure out how the brain activity evoked by different tactics of cognitive reappraisal completes the information transmission across different brain regions,and then determine what role of the brain region plays in the specific tactic of reappraisal.Such research has important academic significance on investigating the neural mechanism of cognitive reappraisal.We firstly investigated the way that different tactics of cognitive reappraisal regulated electrophysiological activities.Then,we investigated the causality of specific prefrontal cortex in cognitive reappraisal using the technique of transcranial magnetic stimulation(TMS)-electroencephalogram(EEG)co-registration based on the temporal and spatial characteristics of neural activity in the specific tactic of cognitive reappraisal.Three types of cognitive reappraisal experiments were designed.All participants were healthy people.The first experiment unlimited the ways that participants implemented cognitive reappraisal to reduce the response to negative emotional stimulus.The second one gave specific descriptions about the stimulus before the stimulus onset and instructed participants to understand the meaning of the stimulus according to the given descriptions,in order to allow all participants to use the same reinterpretations reappraising the stimuli.The last one was the paradigm with TMS-EEG co-registration.The first two experiments aimed to compare the regulatory effects of different tactics of cognitive reappraisal on neural activity.Next,the intervention parameters of TMS-EEG were determined according to the analysis of EEG data from the second experiment.Accordingly,we selected the left ventrolateral prefrontal cortex(VLPFC)as the targeted site;300 ms and 3300 ms after the stimulus onset as the stimulating time points.In all three experiments,participants were instructed to reappraise negative emotional stimuli and rated the valence and arousal of stimulus after the stimulus offset.We applied event-related brain potential(ERP),ERP source localization,event-related spectral perturbation(ERSP)and complex brain network analyses to analyze EEG data from different brain regions and time windows,in order to investigate how cognitive reappraisal impacted neural activity.We concluded:1)Different regulation effects on neural activity were involved in different cognitive processes of reappraisal.In the first experiment,participants were divided into the success group and the failure group according to the ratings of valence and arousal to negative stimuli.If the participant significantly reduced the ratings of unpleansantness(valence ratings increase)and emotional arousal,he/she belonged to the success group;otherwise,he/she belonged to the failure group.The ERP data indicated that there were two time windows in which the success group differed from the failure group.In the 200-300 ms latency window,post-stimulus,P200 was significantly more positive to the negative-watch condition relative to both negative-reappraisal and neutral conditions in the failure group while no condition difference was observed in the success group.In the LPP latency window(300-5000ms),cognitive reappraisal led to increased LPP relative to negative-watch at early and middle latency windows(300-3100ms)in both the reappraisal success and failure groups;at the late latency window(3100-5000 ms),the reappraisal success group showed the LPP amplitude difference between the cognitive reappraisal and negative watch conditions,while no difference was found in the reappraisal failure group.In the second experiment,the proportion of successful reappraisal was 86.2%.Results in reappraisal success indicated that N200 and P200 was affected by the given descriptions that negative stimuli differed with reappraisal stimuli.Moreover,negative reappraisal stimuli decreased the LPP amplitude on the left prefrontal and the central regions in 300-800 ms after the image onset and increased the LPP amplitude on the parietal region.Then,the LPP amplitude on the left prefrontal region was reduced again in 3000-5000 ms.2)Specific tactic(reinterpretation)shifted cognitive reappraisal to earlier time points before the stimulus onset.During participants viewed the descriptions about the image,the reinterpretation of the negative emotional stimulus led to an increase in the early(900-1700ms)and late(3000-4000ms)SPN amplitudes on the left prefrontal region,suggesting that such reinterpretation enhanced the orientation,preparation and anticipation of the upcoming stimuli.In the early stage of emotional processing(200-300ms)after the image onset,the specific descriptions about reinterpretation distinguished the N200 component on the left and right prefrontal and central regions,and the P200 component on the parietal region.In the early stage of cognitive reappraisal(300-800ms),negative reappraisal reduced the LPP amplitudes on the left prefrontal and central regions,and increased the LPP amplitude on the parietal region.In the late stage of cognitive reappraisal(3000-5000ms),negative reappraisal reduced the LPP amplitude on the left prefrontal region.In addition,the reinterpretation tactic increased the theta oscillation on the right prefrontal region and reduced the alpha oscillation on the central region.Our results suggested that from the descriptions onset to the image offset,the tactic of reinterpretation enhanced the orientation,preparation and anticipation process for the upcoming negative stimulus when participants viewed the descriptions.Then,different descriptions impacted the initial stage of emotional processing.Next,the reinterpretation tactic regulated the neural activities on the left/right prefrontal,central and parietal regions after 300 ms.The whole process reflected the temporal dynamics of the reinterpretation tactic.Also,the brain regions involved in the reinterpretation process changed over time:in 200-300ms,the inferior parietal lobe executed the function of cognitive control and chose to focus on the stimuli of negative reappraisal.In the early stage(300-800ms)of cognitive reappraisal,the insula was involved in the process of reinterpretation;in the middle stage(800-3000ms),the ventral anterior cingulate gyrus regulated the cortex that produced negative emotional response;in the late stage(3000-5000ms),the insula continued to implement the reinterpretation tactic and continuously adjusted the process of cognitive reappraisal,showing the recurrence characteristic of the cognitive reappraisal.Specially,the reinterpretation tactic activated the inferior parietal lobe and the left middle frontal gyrus in the early stages of emotional processing and cognitive reappraisal.These results reflected the temporal and spacial characteristics of the reinterpretation tactic.3)Single-pulse TMS intervention applied on the left VLPFC regulated neural activity of cognitive reappraisal and improved the valence ratings to negative reappraisal stimuli,demonstrating that the left VLPFC is an important region in the process of the reinterpretation tactic of cognitive reappraisal.Specifically,compared with the TMS on the control site,the TMS on the left VLPFC improved the valence ratings to negative reappraisal stimuli at two stimulating time points 300ms and 3300ms.TMS applied on the left VLPFC at 300ms impacted the neural activity in the early stages of emotional processing(200-3 00ms)and cognitive reappraisal(300-800ms)while the TMS Intervention at 3300 ms did not affect the neural activity of cognitive reappraisal.In addition,the TMS applied on the left VLPFC at 300ms increased the LPP amplitude on the central region in 300-800ms.This change on neural activity determined the valence rating to negative reappraisal stimuli on behavior.That means higher the LPP amplitude on the central region,less unpleasantness on the valence rating to the negative reappraisal stimuli.Moreover,the TMS on the left VLPFC affected the activities of brain regions involved in the early stage of emotional processing,including the left inferior frontal gyrus and the left posterior central gyrus in the parietal lobe.Further,it also affected the neural activity in the early stage of cognitive reappraisal,including the left inferior temporal gyrus and the left inferior parietal lobe.The results indicated that different brain regions above interacted in the process of cognitive reappraisal.Finally,using the analysis of the complex brain network,we found that the TMS applied on the left VLPFC at 300ms specifically shortened the characteristic path length of the negative reappraisal stimuli under the threshold 0.7 in the theta band,which enhanced capability of parallel information processing and accelerated the transmission efficiency of neural information during the process of cognitive reappraisal.In summary,we designed different types of cognitive reappraisal experiments and investigated the dynamical characteristics of neural activity in different processes of cognitive reappraisal using various methods of EEG analysis,and then suggested a temporal and spacial neural network in cognitive reappraisal.Importantly,we demonstrated the causality of the left VLPFC in the specific tatic of reinterpretation in cognitive reappraisal.Our results enriched the understanding of the time-varying characteristics of neurai activity during cognitive reappraisal.The paradigm of TMS intervention used in this intervention also provided an underlying program for emotional regulation training and for clinical therapy on mood disorders.