The Neural Basis Of Smoking Cue Response And The Prediction Of The Therapeutic Effect Of Neurofeedback Intervention

A common characteristic of nicotine addiction is smoking cue reactivity.Lots of studies have shown that smoking cue reactivity is associated with relapse or continued withdrawal in abusers.At the same time,lots of fMRI and EEG studies have proved that drug cure reactivity involves lots of brain regions or rapid cognitive processes.However,fMRI has the disadvantage of low temporal resolution,which makes it difficult to found results of temporal processes inevitably.In contrast,EEG studies have relatively limited results of brain networks.Based on the clinical value of smoking cue reactivity in the treatment of addiction,it is necessary to explore the brain mechanism of that through a new method.Neurofeedback training is a promising method for the treatment of addiction.However,the long-term effect and the applicable population of this method are still unclear.Therefore,these two questions are also the focus of this study.The research on the mechanism of smoking cue reactivity will help to provide a target for addiction treatment.Advances in the treatment of addiction are also conducive to the development of individuals and society.To solve the problems above,we designed three experiments:In experiment 1,we assessed the cortical connectivity of nicotine dependent smokers in response to smoking cues based on EEG coherence.EEG technology was used to measure the EEG coherence of the subjects of nicotine dependent group(25 participants)and non-smoking group(22 participants)on smoking or neutral cue reactivity tasks.The result found that the subjects in nicotine dependent group showed a significant brain network of low-theta coherence in the frontal-parietal region when faced with smoking cues,which also showed a significant correlation with changes in smoking craving.However,there were no similar results in control group.In experiment 2,we investigated whether the mean coherence network above could predict abusers' drug craving.To solve the problem of reproducibility of the results of neuroimaging studies,13 nicotine dependent subjects were recruited for experiment 2,who also completed the cue reactivity task for conducted external verification.The results showed that the estimated correlation model for predicting the variation of smoking craving based on the coherence of low-theta network in experiment 1 could effectively predict the subjective craving level in experiment 2.In experiment 3,using EEG based neurofeedback technology,60 subjects were randomly assigned to the real feedback and sham control groups.Firstly,we investigated the long-term effects of feedback training.At the same time,subjects were asked to complete a resting-EEG task for two times before and after the feedback training.In this way,we could find a predictor of the long-term effects of feedback training.The results showed that the real feedback group had a significant decline in daily smoking during the four month follow-up.There was a significant correlation between delta power in the resting state before the feedback training and the long-term effects.However,no such results were found in the sham control group.According to the results of the three experiments above,we draw the following conclusions:(1)The coherence of the low-theta network(3-5Hz,400-600ms after stimulation cues were presented)in frontal-parietal area was enhanced when nicotine abusers faced smoking cues.(2)The average coherence of low-theta network can significantly predict the changes of craving in nicotine abusers.(3)The real feedback group showed a significant decline in daily smoking during the four month follow-up.(4)Delta power in resting state before feedback training is a stable and specific predictor of the long-term effect of neurofeedback training.