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  • Because of its abstract nature, worrying might function as an avoidance response in order to cognitively disengage from fearful imagery. The present functional magnetic resonance imaging study investigated neural correlates of aversive imagery and their association with worry tendencies, as measured by the Penn State Worry Questionnaire (PSWQ). Nineteen healthy women first viewed, and subsequently imagined pictures from two categories, 'threat' and 'happiness'. Worry tendencies were negatively correlated with brain activation in the anterior cingulate cortex, the prefrontal cortex (dorsolateral, dorsomedial, ventrolateral), the parietal cortex and the insula. These negative correlations between PSWQ scores and localized brain activation were specific for aversive imagery. Moreover, activation in the above mentioned regions was positively associated with the experienced vividness of both pleasant and unpleasant mental pictures. As the identified brain regions are involved in emotion regulation, vivid imagery and memory retrieval, a lowered activity in high PSWQ scorers might be associated with cognitive disengagement from aversive imagery as well as insufficient refresh rates of mental pictures. Our preliminary findings encourage future imagery studies on generalized anxiety disorder patients, as one of the main symptoms of this disorder is excessive worrying.

  • RATIONALE: Biased processing of drug-associated stimuli is believed to be a crucial feature of addiction. Particularly, an attentional bias seems to contribute to the disorder's maintenance. Recent studies suggest differential effects for stimuli associated with the beginning (BEGIN-smoking-stimuli) or the terminal stage of the smoking ritual (END-smoking-stimuli), with the former but not the later evoking high cue-reactivity. OBJECTIVE: The current study investigated the neuronal network underlying an attentional bias to BEGIN-smoking-stimuli and END-smoking-stimuli in smokers and tested the hypothesis that the attentional bias is greater for BEGIN-smoking-stimuli. METHODS: Sixteen non-deprived smokers and 16 non-smoking controls participated in an fMRI study. Drug pictures (BEGIN-smoking-stimuli, END-smoking-stimuli) and control pictures were overlaid with geometrical figures and presented for 300 ms. Subjects had to identify picture content (identification-task) or figure orientation (distraction-task). The distraction-task was intended to demonstrate attentional bias. RESULTS: Behavioral data revealed an attentional bias to BEGIN-smoking-stimuli but not to END-smoking-stimuli in both groups. However, only smokers showed mesocorticolimbic deactivations in the distraction-task with BEGIN-smoking-stimuli. Importantly, these deactivations were significantly stronger for BEGIN- than for END-smoking-stimuli and correlated with the attentional bias score. CONCLUSIONS: Several explanations may account for missing group differences in behavioral data. Brain data suggest smokers using regulatory strategies in response to BEGIN-smoking-stimuli to prevent the elicitation of motivational responses interfering with distraction-task performance. These strategies could be reflected in the observed deactivations and might lead to a performance level in smokers that is similar to that of non-smokers.

  • An important feature of addiction is the high drug craving that may promote the continuation of consumption. Environmental stimuli classically conditioned to drug-intake have a strong motivational power for addicts and can elicit craving. However, addicts differ in the attitudes towards their own consumption behavior: some are content with drug taking (consonant users) whereas others are discontent (dissonant users). Such differences may be important for clinical practice because the experience of dissonance might enhance the likelihood to consider treatment. This fMRI study investigated in smokers whether these different attitudes influence subjective and neural responses to smoking stimuli. Based on self-characterization, smokers were divided into consonant and dissonant smokers. These two groups were presented smoking stimuli and neutral stimuli. Former studies have suggested differences in the impact of smoking stimuli depending on the temporal stage of the smoking ritual they are associated with. Therefore, we used stimuli associated with the beginning (BEGIN-smoking-stimuli) and stimuli associated with the terminal stage (END-smoking-stimuli) of the smoking ritual as distinct stimulus categories. Stimulus ratings did not differ between both groups. Brain data showed that BEGIN-smoking-stimuli led to enhanced mesolimbic responses (amygdala, hippocampus, insula) in dissonant compared to consonant smokers. In response to END-smoking-stimuli, dissonant smokers showed reduced mesocortical responses (orbitofrontal cortex, subcallosal cortex) compared to consonant smokers. These results suggest that smoking stimuli with a high incentive value (BEGIN-smoking-stimuli) are more appetitive for dissonant than consonant smokers at least on the neural level. To the contrary, smoking stimuli with low incentive value (END-smoking-stimuli) seem to be less appetitive for dissonant smokers than consonant smokers. These differences might be one reason why dissonant smokers experience difficulties in translating their attitudes into an actual behavior change.

Last update from database: 11.08.25, 05:41 (UTC)