The Static Impairment And Dynamic Weakening Of Cognitive Control In Addicts

The functional impairment of cognitive control,especially inhibitory control,has been proved to be an essential factor in the development and maintenance of addictive behaviors.In order to explore the unitary and the specificity of different categories of addiction,the author proposed a model of the Static Impairment and Dynamic Weakening of Cognitive Control in Addicts.There are three central assumptions of the model:(1)Compared with healthy individuals,addicts manifest static impairment of cognitive control;(2)The cognitive control of addicts would be further weakened under the varying environments,for example,the motivational cues and mental cues in the circumstance;(3)There are similarities and discrepancy in aforementioned static impairment and dynamic weakening of cognitive control in substance and behavioral addicts.Three studies were conducted to verify this model,in which abstinent methamphetamine-dependent individuals(MDs)and excessive social media use individuals(ESMUs)were recruited as the representative groups of substance and behavioral addiction.Study 1 investigated the static impairment of the following dimensions of cognitive control in MDs and ESMUs via 4 experiments(8 sub-experiments):(1)working memory resources used to execute cognitive control;(2)the basic levels and the relative utilization mode of proactive and reactive control;(3)conflict inhibition and(4)prepotent response inhibition(both with proactive and reactive control capacities evaluated separately).Study 2 explored the dynamic weakening caused by(approach /avoidance)motivational cues on proactive/reactive response inhibition of MDs and ESMUs through 2 experiments(4 sub-experiments).In study 3,2 experiments(4 subexperiments)were deployed to investigate the dynamic weakening caused by(endogenous working memory / exogenous visual attentional)load on proactive/reactive response inhibition of MDs and ESMUs.The main conclusions of the present study include:(1)Both MDs and ESMUs show deficiency in working memory resources that are essential for utilizing cognitive control and entail a decrease in overall cognitive control,nevertheless the impairments of MDs’ cognitive control are more severe than that of ESMUs.(2)In regard to inhibitory control,MDs exhibit insufficient function of behavioral prepotent response inhibition,wheras ESMUs mainly manifest impairment of cognitive conflict inhibition.(3)Exposure to approach motivational cues limits the functions of inhibitory control in both MDs and ESMUs,though the mechanisms are different.MDs demonstrate deteriorated impairment of reactive inhibition when exposed to methamphetamine cues;meanwhile ESMUs illustrate further impairment of proactive inhibition induced by social media cues.(4)The priming of avoidance motivational cues(negative emotional cues)weakens the proactive inhibition of MDs and ESMUs.For MDs,there are a positive correlation between the degree of proactive inhibition weakening and the years of drug use.As for ESMUs,negative emotional cues first overactivate their monitoring process of proactive control,followed by the weakened proactive behavioral inhibition due to excessive resource depletion.(5)Both endogenous working memory load and exogenous visual attentional load limit the cognitive control function of MDs and ESMUs.In specific,working memory load has a significant weakening effect on the proactive/reactive control in both groups;visual attentional load,however,limits the reactive inhibition of both groups.Nevertheless,there are discrepancy between the two groups that working memory load has a greater limiting effect on MDs,while ESMUs are more sensitive to visual attentional load,both of which directly lead to an increased probability of inhibitory control failure.Finally,the author proposed a theoretical framework accounting for the impairment of cognitive control and its dynamic changes in substance/behavioral addicts.Under this theoretical framework,researchers are able to make a comparative analysis of the characteristics of the functional impairment of cognitive control on different addiction groups,so as to deeply clarify the substantial role of cognitive control in the development and maintenance of substance and behavioral addiction.