A Study On The Attentional Bias Of Methamphetamine Addicts

Recently,meth has overtaken heroin as the main source of drug addiction.Previous studies have suggested that drug addiction may lead to an abnormal bias for addicts to pay more attention to the cues of addiction and showed abnormal bias in emotion.This study adopted dot-probe task to explore the characteristics of attention bias of meth addicts through three experiments.In experiment 1,2 groups(addiction group,normal group)x2 picture’s correlation to addiction(addictive relevant,addictive irrelevant)was designed to explore the characteristics of attentional bias to addictive clues.The results of response time showed that(1)the main effect of groups was significant,and the response time of addiction group was shorter than normal group.The main effect of picture’s correlation to addiction was significant,and the response time to point after addictive relevant was significantly longer than addictive irrelevant,but the interaction was not significant.(2)The results of further analysis of response time when the dot presented after addictive irrelevant under these two presentations in both groups showed that the main effect of groups was significant and the addiction group was faster than the normal group.The main effect of the presentation conditions was significant,and the response time to the addictive irrelevant-addictive relevant was significantly longer than the addictive irrelevant-addictive irrelevant condition.The interaction effect between groups and presentation conditions was significant.In addiction group,response time to relevant-irrelevant condition was significantly longer than irrelevant-irrelevant condition,and there was no significant difference between those two kinds of presentation conditions in the normal group.This suggests that meth addicts may have a bias towards addiction-related stimuli.In experiment 2,2 groups(addiction group,normal group)x3 picture’s valence of emotional clues(positive,negative,neutral)was designed to explore the characteristics of attentional bias to emotional clues.The results showed that(1)there was no significant difference between addiction group and normal group.The main effect of picture’s valence of emotional clues was not significant and the interaction effect between two factors wasn’t significant.(2)Further analysis to compare the response time of the same clues of emotion under different presentation in both groups showed that the response time to positive-negative was significantly longer than positive-neutral when the point was observed after positive pictures.There was no significant difference between different presentations when the point was observed after negative pictures and neutral picture.This suggests that meth addicts,like normal people,have more attention to negative emotional stimuli.In experiment 3,2 groups(addiction group,normal group)×2 picture’s correlation types to clues(addiction relevant,emotion relevant)was designed to explore the characteristics of attentional bias between addictive and emotional clues.The results of response time showed that(1)When the dot showed after addiction clues,the analysis showed that there was no main effect of groups and presentations and the interaction.(2)When the dot showed after emotional clues,the analysis showed that the main effect of presentations was significant,showing that the response time to positive-addictive was significantly longer than neutral-addictive,the response time to negative-addiction was significantly longer than neutral-addiction,and the difference of response time was not significant between positive-addiction and negative-addiction.(3)Further analysis showed there was no significant effect of picture’s correlation types to clues in addiction-positive and addiction-negative.But the response time to addiction was significantly longer than neutral emotion in addiction-neutral.This suggests that positive and negative clues of emotion may be competing with addictive cues in attention in both two groups.The above results indicated that:(1)in a condition of addictive independent stimulation or neutral stimulation,the addicts may have an attentional bias to the addictive stimuli,which showed a difficulty in disengaging to addiction stimulus.(2)in a condition without addiction stimulation,both the normal and the addicts will pay more attention to negative emotional stimulation;(3)in the context of the co-existence of addictive and emotional stimulation,there is a competition in attention between emotional stimulation and addictive stimulation,which seems to be appeared in both addiction’ group and normal group,but the mechanism in attentional bias processing to addiction might be different in two groups.